Lost circulation materials (LCM's) effective to maintain emulsion stability of drilling fluids

Information

  • Patent Application
  • 20030158045
  • Publication Number
    20030158045
  • Date Filed
    August 29, 2002
    22 years ago
  • Date Published
    August 21, 2003
    21 years ago
Abstract
Lost circulation materials and methods for maintaining emulsion stability in emulsion type drilling, drill-in, and completion fluids, particularly invert emulsions.
Description


FIELD OF THE INVENTION

[0002] The present invention relates to lost circulation materials, and to methods for maintaining emulsion stability in emulsion type drilling, drill-in, and completion fluids (hereinafter sometimes collectively referred to as “drilling fluids”) containing lost circulation material(s).



BACKGROUND OF THE INVENTION

[0003] Drilling fluids serve various functions, such as promoting borehole stability, removing drilled cuttings from the wellbore, cooling and lubricating the bit and the drillstring, as well as controlling subsurface pressure. Certain subsurface conditions can cause, or lead to, “loss of circulation,” or the loss of whole drilling fluid in quantity to the formation. Examples of such subsurface conditions include, but are not necessarily limited to: (1) natural or intrinsic fractures, (2) induced or created fractures; (3) cavernous formations (crevices and channels), and (4) unconsolidated or highly permeable formations (loose gravels).


[0004] Lost circulation materials are used to minimize loss of circulation. The lost circulation material forms a filter cake that effectively blocks voids in the formation. Currently, lost circulation materials include fibrous materials, such as cedar bark and shredded cane stalk, flaky materials such as mica flakes, and granular materials such as ground limestone, wood, nut hulls, corncobs, and cotton hulls.


[0005] Unfortunately, low electrical stability values have been reported for invert emulsion drilling fluids containing fibrous cellulosic lost circulation material. If the electrical stability value of a drilling fluid becomes too low, water wetting of solids occurs, which may cause the rheological properties of the fluid to break down, rendering the drilling fluid ineffective and even resulting in a shutdown of drilling operations.


[0006] Lost circulation materials and methods of use are needed which maintain electrical stability, and thereby emulsion stability of drilling fluids.



SUMMARY OF THE INVENTION

[0007] The invention provides a method for maintaining electrical stability in a drilling, drill-in, or completion fluid comprising lost circulation material (LCM), said method comprising:


[0008] providing an initial fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said initial fluid having effective rheology and fluid loss control properties;


[0009] adding to said initial fluid a fibrous LCM consisting essentially of a quantity of high lignin lost circulation material (HLLCM), thereby producing a treated fluid.


[0010] In another aspect, the invention provides a method for maintaining electrical stability in a drilling, drill-in, or completion fluid, said method comprising:


[0011] providing an initial fluid selected from the group consisting of a drilling, drill-in, or completion fluid having effective rheology and fluid loss control properties; and


[0012] using as LCM in said initial fluid a fibrous HLLCM having a water retention value of about 1 or less.


[0013] In yet another aspect, the invention provides a method for maintaining electrical stability in a drilling, drill-in, or completion fluid, said method comprising:


[0014] providing an initial fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said initial fluid having effective rheology and fluid loss control properties; and


[0015] using grape pumice as a lost circulation material.


[0016] In preferred embodiments, said initial fluid exhibits a first electrical stability value and said treated fluid exhibits a second electrical stability value that is a maximum of 18% less than said first electrical stability value; more preferably 15% less than said first electrical stability value; most preferably 12% less than said first electrical stability value. The initial fluid preferably is an emulsion base fluid, most preferably an invert emulsion fluid. The fibrous HLLCM preferably has a water retention value of about 1 or less, more preferably about 0.5 or less, even more preferably about 0.3 or less. Preferred HLLCM's are selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from processing plant material into paper. A most preferred HLLCM is grape pumice. The HLLCM preferably comprises a particle size distribution of from about 10 μm to about 200 μm.


[0017] In another aspect, the invention provides a fluid selected from the group consisting of a drilling, drill-in, or completion fluid having effective rheology and fluid loss control properties and comprising a lost circulation material consisting essentially of an HLLCM.


[0018] In another aspect, the invention provides a fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said fluid having effective rheology and fluid loss control properties and consisting essentially of an LCM having a water retention value of about 1 or less.


[0019] In another aspect, the invention provides a fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said fluid having effective rheology and fluid loss control properties and comprising a fibrous LCM, said fibrous LCM consisting essentially of materials selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from the processing of plant material into paper.


[0020] In yet another aspect, the invention provides a fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said fluid having effective rheology and fluid loss control properties and comprising a fibrous LCM consisting essentially of grape pumice.


[0021] In preferred embodiments, the initial fluid exhibits a first electrical stability value and a fluid comprising said HLLCM exhibits a second electrical stability value that is a maximum of 18% less than said first electrical stability value; more preferably 15% less than said first electrical stability value; most preferably 12% less than said first electrical stability value. The initial fluid preferably is an emulsion base fluid, most preferably an invert emulsion fluid. The fibrous HLLCM preferably has a water retention value of about 1 or less, more preferably about 0.5 or less, even more preferably about 0.3 or less. Preferred HLLCM's are selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from processing plant material into paper. A most preferred HLLCM is grape pumice. The HLLCM preferably comprises a particle size distribution of from about 10 μm to about 200 μm.


[0022] In yet another aspect, the invention provides a spotting pill comprising from about 1 to about 100 ppb of an HLLCM and a carrier liquid. Preferably, the spotting pill comprises from about 5 to about 50 ppb of an HLLCM and a carrier liquid.


[0023] The HLLCM preferably consists essentially of materials selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from the processing of plant material into paper. In a most preferred embodiment, the HLLCM is grape pumice.


[0024] In yet another aspect, the invention provides a spotting pill comprising from about 1 to about 100 ppb grape pumice a carrier liquid, preferably from about 5 to about 50 ppb of grape pumice and a carrier liquid.


[0025] The carrier liquid preferably is selected from the group consisting of a polyalkylene oxides and copolymers thereof, polyalkyleneoxide glycol ethers, glycols, polyglycols, tripropylene glycol bottoms, and combinations thereof. In a preferred embodiment, the carrier liquid is selected from the group consisting of ethylene glycols, diethylene glycols, triethylene glycols, tetraethylene glycols, propylene glycols, dipropylene glycols, tripropylene glycols, tetrapropylene glycols, polyethylene oxides, polypropylene oxides, copolymers of polyethylene oxides and polypropylene oxides, polyethylene glycol ethers, polypropylene glycol ethers, polyethylene oxide glycol ethers, polypropylene oxide glycol ethers, and polyethylene oxide/polypropylene oxide glycol ethers. In another preferred embodiment, the carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.


[0026] In a most preferred embodiment, the carrier liquid comprises tripropylene glycol bottoms. In a most preferred embodiment, the HLLCM is grape pumice, most preferably combined with tripropylene glycol bottoms. Where alkalinity of the drilling fluid is a concern, the pH may be maintained by using about 0.2 lb soda ash to about 1 lb grape pumice, in the spotting additive, or during mixing.







BRIEF DESCRIPTION OF THE DRAWINGS

[0027]
FIG. 1 is a graph showing comparative LCM effects upon electrical stability in a field ECO-FLOW sample.


[0028]
FIG. 2 is a graph showing a particle size distribution analyses of CHECK-LOSS® in various fluids.







DETAILED DESCRIPTION OF THE INVENTION

[0029] Measurements of an emulsion-type drilling fluid are continually made in an effort to identify any loss in emulsion stability resulting from loss of circulation of the drilling fluid. A preferred method of measuring emulsion stability in invert emulsion drilling fluids is to measure the electrical stability of the drilling fluid.


[0030] The electrical stability of an oil-based drilling fluid relates both to its emulsion stability and to its oil-wetting capability. Electrical stability of a drilling fluid is determined by applying a voltage-ramped, sinusoidal electrical signal across a pair of parallel flat-plate electrodes immersed in the drilling fluid. The resulting current remains low until a threshold voltage is reached, whereupon the current rises very rapidly. This threshold voltage is the electrical stability of the drilling fluid and is defined as the voltage in peak volts-measured when the current reaches 61 μA.


[0031] Field operators monitor the emulsion stability of a drilling fluid by reading the voltage across the drilling fluid. The resulting electrical stability reading is directly related to the ratio of water to oil in a particular drilling fluid. As the concentration of water in the drilling fluid increases, the electrical stability value tends to decrease.


[0032] The reported decrease in electrical stability values in invert emulsion drilling fluids appears to be attributable to swollen, hydrated fibers of lost circulation material that come into contact with the electrical stability meter probe. In order to preserve electrical stability (and thereby emulsion stability), water wetting of such fibrous materials must be minimized.


[0033] The type of lost circulation material added to a particular drilling fluid varies according to the primary purpose of the drilling operation; the nature of the rocks to be penetrated; the site, and the skill and experience of the drilling crew. Various plant source fibers are used as lost circulation materials. Cellulose is a major constituent of most plant cell walls, and also has a high affinity for water. Without limiting the invention to a particular mechanism of action, the decrease in electrical stability of drilling fluids comprising many fibrous lost circulation materials is believed to be due to the intrinsic affinity of the cellulose in those fibers for water. In order to reduce the impact of a lost circulation material on electrical stability readings, the present invention reduces the cellulosic content of the fibrous material.


[0034] Lignin also is found in plant cell walls. Lignin is a strengthening polymer which provides rigidity and strength to the plant material. Lignin does not have as great an affinity for water as cellulose. Plant materials with higher lignin contents should have a directly or indirectly proportional decrease in affinity for water. It is difficult to analyze plant materials directly to determine their lignin content.


[0035] The present invention involves the use of “high lignin” lost circulation materials (HLLCM's) in drilling fluids. HLLCM's increase electrical stability values in emulsion type fluids, and thereby increase emulsion stability. “HLLCM's” are herein defined as fibrous lost circulation materials effective to maintain the electrical stability value of a given drilling, drill-in or completion fluid to within 20% or less of the electrical stability value of the same fluid in the absence of the HLLCM. Preferred HLLCM's are effective to maintain the electrical stability value of a given drilling, drill-in or completion fluid within 18% of the electrical stability value of the same fluid in the absence of the HLLCM, more preferably to within about 15%, and most preferably to within about 12%. Another way of stating the electrical stability limitation is that the addition of the HLLCM causes a maximum reduction in voltage reading of 20% or less relative to the initial voltage reading, more preferably about 18% or less, even more preferably about 15 % or less, most preferably about 12% or less.


[0036] Suitable HLLCM's may be identified with reference to their “Water Retention Value” (WRV). A given plant material has a given hydration rate based on the size of voids within the fibers of that plant material. When the dry plant material is exposed to water, these voids are swollen by the water. The swelling of these voids in the presence of water may be measured, and the measured value is known as the material's WRV. The WRV is a measure of the amount of water intimately associated with a given dry weight of a given plant material, and is approximately equal to the total change in volume of the cell wall of the plant material.


[0037] The WRV for a given plant material may be calculated upon performing a simple test. Add 25 g test material to a glass jar. Mix 250 ml of deionized water with the test material. Shear the slurry at 3000 rpm for 5 min. Cap the glass jar roll 16 hr at 150° F. After cooling, pour the jar contents into an assembled Buchner funnel (using Whatman filter paper No. 41) fitted on a 2-liter Erlenmeyer flask, hooked to a vacuum pump. Filter for two hours maximum. Remove the Buchner funnel with test material from the flask and weigh. Calculate the WRV using the following equation:


(Buchner funnel with filter (Buchner funnel with wet paper)−paper and retained wet test material)/Initial 25 g dry test material.


[0038] Fibrous lost circulation materials in current use have a calculated WRV of about 4 or more. HLLCM's that are suitable for use in the present invention have a calculated WRV of 1 or less, preferably 0.5 or less, and more preferably 0.3 or less.


[0039] Examples of suitable HLLCM's include, but are not necessarily limited to plants that actually grow in water but tend to remain dry, such as bulrush plants, which include cattails, papyrus, and the like. Also suitable are lignin byproducts derived from the processing of wood or other plant materials into paper. The products made from such processes typically require high contents of cellulose, and lignin is processed out of the wood. The lignin typically is sold for sulfonation.


[0040] The HLLCM generally has a particle size distribution effective to form a filter cake and to block loss of circulation of the drilling fluid to the formation. Suitable particle size distributions generally are from about 10 μm to about 200 μm, preferably from about 15 to about 170.


[0041] A most preferred HLLCM for use in the invention is grape pumice. HLLCMs, preferably grape pumice, have the added advantage of inducing less impact upon rheological properties.


[0042] The HLLCM preferably is used in emulsion type drilling fluids, most preferably invert emulsion drilling fluids. However, HLLCM's are useful as a lost circulation materials in any type of drilling fluid, including water base fluids, natural or synthetic oil base fluids, oil-in-water emulsion fluids, and water-in-oil emulsion fluids.


[0043] The HLLCM may be included as an integral part of a drilling fluid, and/or added to a drilling fluid, as needed, during drilling operations. Where the HLLCM is used as an integral part of a drilling fluid, the quantity used is from about 0.1 ppg to about 25 ppg, preferably from about 5 ppg to about 10 ppg. Where the HLLCM is added to the drilling fluid as needed during operation, the HLLCM is simply added to the mud pit with mixing, as needed. The quantity of HLLCM added will vary depending upon the extent of the loss in circulation. Typically, the quantity is from about 0.1 ppg to about 25 ppg or more.


[0044] Alternately, the HLLCM is added to the mud pit as a spotting pill. In this embodiment, the HLLCM is added as a slurry, together with a small amount of a carrier liquid that is compatible with the fluid being treated. A preferred slurry comprises from about 1 ppb to about 100 ppb HLLCM, preferably about 5 to about 50 ppb HLLCM. A most preferred spotting pill is from about 1 ppb to about 100 ppb grape pumice in a carrier fluid, preferably from about 5 to about 50 ppb grape pumice. Typically, after the HLLCM is spotted opposite the loss zone, it is desirable to pull into the casing and wait six to eight hours before continuing operations.


[0045] Whether used as a integral part of the drilling fluid, or in a spotting pill, certain HLLCM's, such as grape pumice, tend to increase the acidity of water base fluids. Hence, where the HLLCM is used in a water base fluid, it is preferred to add a sufficient quantity of a buffering agent to increase the pH to neutral, or about 7. Suitable buffering agents include but are not necessarily limited to soda ash, sodium bicarbonate, sodium hydroxide, lime, calcium hydroxide, and the like. A suitable amount of buffering agent is from about 0.1 lb to about 0.2 lb, preferably 0.1 lb, for every 10 lbs. HLLCM, preferably grape pumice.


[0046] Suitable carrier fluids for a spotting pill vary depending upon the fluid being treated. Where the fluid is a water base fluid, the carrier preferably will be aqueous. Where the fluid is an oil base fluid, the carrier preferably will be non-aqueous, and so forth. In a preferred embodiment, the carrier fluid is selected from the group consisting of glycols, polyglycols, polyalkyleneoxides, alkyleneoxide copolymers, alkylene glycol ethers, polyalkyleneoxide glycol ethers, and salts of any of the foregoing compounds, and combinations of the foregoing compounds.


[0047] Examples of suitable glycols and polyglycols include, but are not necessarily limited to ethylene glycols, diethylene glycols, triethylene glycols, tetraethylene glycols, propylene glycols, dipropylene glycols, tripropylene glycols, and tetrapropylene glycols. Examples of suitable polyalkyleneoxides and copolymers thereof include, but are not necessarily limited to polyethylene oxides, polypropylene oxides, and copolymers of polyethylene oxides and polypropylene oxides. Suitable polyalkyleneoxide glycol ethers include, but are not necessarily limited to polyethylene glycol ethers, polypropylene glycol ethers, polyethylene oxide glycol ethers, polypropylene oxide glycol ethers, and polyethylene oxide/polypropylene oxide glycol ethers. Preferred carriers are ethylene glycol, tripropylene glycol bottoms, and combinations thereof. A most preferred carrier is tripropylene glycol bottoms.


[0048] The invention will be better understood with reference to the following Examples, which are illustrative only. In the examples, CHEK-LOSS® is a corn cob based LCM, available from Baker Hughes INTEQ; PHENO-SEAL® is a ground plastic resin material, available from Montello, Inc.; MUD-LINER is a paper based LCM, available from BCI Incorporated; LIQUID CASING is a peanut hull based LCM available from Liquid Casing, Incorporated; KWIK SEAL FINE is a blend of vegetable and polymer fibers available from Kelco Oilfield Group; and BAROFIBRE is an almond hull based LCM, available from Baroid/Halliburton.



EXAMPLE 1

[0049] Field operations personnel reported continuing problems of low electrical stability values for invert emulsion drilling fluids containing fibrous lost circulation material (LCM) additives. Although not identifying the specific additives, a report indicated that all fibrous materials lowered electrical stability values. However, HPHT fluid losses of the laboratory test muds showed no evidence of water. The criteria of absence of water in the HPHT filtrate was used as the preferred method of determining emulsion stability.


[0050] The following is an assessment of the effects of various LCM additives on electrical stability, Theological properties, and HPHT/PPA filtration control of synthetic-based fluids.


[0051] Equipment


[0052] 1. Prince Castle mixer


[0053] 2. Fann viscometer, Model 35A


[0054] 3. Thermometer, dial, 0-220° F.


[0055] 4. Balance with precision of 0.01 g


[0056] 5. Sieves (conforming to ASTM E11 requirements)


[0057] 6. Roller oven, 150-250±5° F. (66-121±3° C.)


[0058] 7. Static aging oven


[0059] 8. Wash bottle


[0060] 9. Retsch grinding mill


[0061] 10. Mortar and pestle


[0062] 11. Spatula


[0063] 12. Timer: interval, mechanical or electrical, precision of 0.1 minute


[0064] 13. Jars (approximately 500 ml capacity) with sealing lids


[0065] 14. Heating cup, OFI, 115 volt


[0066] 16. Malvern Mastersizer


[0067] Procedures


[0068] The following INTEQ Fluids Laboratory procedures were used:


[0069] Recommended Practice Standard Procedure for Field Testing Oil-Based Drilling Fluids, API Recommended Practice 13B-2, Third Edition, February 1998


[0070] Recommended Practice Standard Procedure for Field Testing Water-Based Drilling Fluids, API Recommended Practice 13B-1, Second Edition, September 1997


[0071] Instrumentation Manual for Malvern Mastersizer


[0072] The following were the results
1TABLE 1Comparative evaluation of CHEK-LOSS ® and BLEN-PLUG OM in field SYN-TEQ ® samplesMaterialsSYN-TEQ (unknown LCM) Sample A, bbl1.01.01.01.0SYN-TEQ Sample B, bbl1.01.01.0CHEK-LOSS, Sample C, lb/bbl1010BLEN-PLUG OM, Sample D, lb/bbl1010Stirred 15 min1290116010401290220175160Electrical stability, voltRolled 16 hr, 150° F.FANN 35 Properties:600 rpm rdg, 120° F.145233n/m1455470n/m300 rpm rdg82131823039200 rpm rdg6195612128100 rpm rdg3858381317  6 rpm rdg10141034  3 rpm rdg811823Plastic viscosity, cp63102632431Yield point, lb/100 ft21929196810-sec gel, lb/100 ft21012103510-min gel, lb/100 ft213161357Electrical stability, volt1150350330115022015013060-mesh screenedElectrical stability, volt390350Treatment:Baroid DrilTreat, lb/bbl5.05.05.0INTOIL-S, lb/bbl5.0Electrical stability, volt12903853501290CHEK-LOSS, lb1010Rolled 16 hr, 150° F.Electrical stability, volt430440600 rpm rdg, 120° F.205222300 rpm rdg118129200 rpm rdg8795100 rpm rdg5460  6 rpm rdg1415  3 rpm rdg1112Plastic viscosity, cp8793Yield point, lb/100 ft2313610-sec gel, lb/100 ft2151610-min gel, lb/100 ft21819


[0073]

2





TABLE 2










Comparative evaluation of a) wetting agents with CHEK-LOSS ® in a field ECO-FLOW


and b) competitive fibrous LCM additives versus MIL-CARB ® or PHENO-SEAL










A: Wetting Agents with CHEK-LOSS
B: Fibrous LCM versus MIL-CARB
























Materials















ECO-FLOW,
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0


Sample E, bbl


DRILTREAT,


5.0












lb/bbl


INTOIL-S,



5.0











lb/bbl


BIO-COTE ™,




2.5










lb/bbl


OMNI-





2.5









COTE ®,


lb/bbl


CHEK-LOSS,

10
10
10
10
10









lb/bbl


PHENO-






10








SEAL, lb/bbl


LUBRA-







10







SEAL, lb/bbl


BAROFIBRE,








10






lb/bbl


MUD LINER,









10





lb/bbl


LIQUID










10




CASING,


lb/bbl


ULTRASEAL, lb/bbl











10



MIL-CARB,












10


lb/bbl


Stirred 15 min


Rolled 16 hr,


150° F.







Properties




















600 rpm rdg,
122
178
155
168
153
150
125
136
157
198
165
160
124


120° F.


300 rpm rdg
72
100
88
95
80
80
73
79
90
112
94
90
73


200 rpm rdg
52
73
66
70
54
57
54
59
65
81
68
67
54


100 rpm rdg
33
45
41
43
30
33
34
36
41
49
42
45
33


  6 rpm rdg
10
12
11
12
4
4
10
10
11
12
11
13
10


  3 rpm rdg
8
10
9
10
3
3
8
8
10
11
10
12
8


Plastic
50
78
67
73
73
70
52
57
67
86
71
70
51


viscosity, cp


Yield point,
22
22
21
22
7
10
21
22
23
26
23
20
22


lb/100 ft2


10-sec gel,
11
12
12
12
4
4
11
11
12
13
12
12
11


lb/100 ft2


10-min gel,
14
15
15
16
6
9
14
15
14
16
15
15
14


lb/100 ft2


Electrical
1170
620
640
500
440
480
1170
720
850
500
650
750
1160


stability, volt


HPHT
10.8
11.2




10.0
10.6
11.6
10.8
10.2
10.8
10.0


(250° F.), ml


Water in
no
no




no
no
no
no
no
no
no


filtrate










[0074]

3





TABLE 3








Effect of CHEK-LOSS ® on electrical stability and particle size



























Materials














ISO-TEQ ®,


0.75
0.75
0.85
0.85
0.95
0.95
1.00
1.00
1.00
1.00


bbl


OMNI-


12
12
12
12
12
12
12
12




MUL ®, lb/bbl


Deionized
1.00
1.00
0.25
0.25
0.15
0.15
005
0.05






Water, bbl


CHEK-

50

50

50

50

50

50


LOSS ®, lb/bbl


Stirred 30 min


Rolled 16 hr,


150° F.


Properties


Electrical
<5
<5
150
10
230
15
1100
95
2000
2000
2000
2000


stability, volt


Particle Size


Analyses


by Malvern


D (v, 0.1)

17.9

23.6

36.8

16.4

17.9

15.1


D (v, 0.5)

64.5

84.3

95.2

70.3

60.7

65.6


D (v, 0.9)

142

204

203

169

137

175










[0075]

4





TABLE 4








Evaluation of Other fibrous LCM additives as compared to CHEK-LOSS ®






















Materials









UNOCAL ECO-
1.0
1.0
1.0
1.0
1.0
1.0
1.0


FLOW


Field Sample (FSR 4341d), bbl


CHEK-LOSS, lb/bbl

10







Slurry Blend*, lb/bbl


12.5






LCM Blend**, lb/bbl



10





KWIK-SEAL Fine,




10




lb/bbl


MASTERSEAL, lb/bbl





10



LCP***, lb/bbl






10


Stirred 30 min


Rolled 16 hr, 150° F.







Properties














Electrical stability, volt
1470
700
740
880
1280
1300
970


600 rpm rdg, 120° F.
126
175
128
166
134
137
150


300 rpm rdg
72
100
70
95
77
77
85


200 rpm rdg
53
78
50
70
58
57
60


100 rpm rdg
32
49
31
42
37
36
37


  6 rpm rdg
8
12
8
11
10
10
10


  3 rpm rdg
7
10
7
10
8
8
8


Plastic viscosity, cp
54
75
58
71
57
60
65


Yield point, lb/100 ft2
18
25
12
24
20
17
20


10-sec gel, lb/100 ft2
10
11
9
13
12
11
12


10-min gel, lb/100 ft2
13
15
11
15
14
14
14


HPHT (250° F.), cm3/30 min
2.0
2.4


2.4
2.0



Water in Filtrate?
no
no


no
no







Notes:




*Slurry blend prepared by mixing 0.86 bbl ISO-TEQ ®, 12 lb/bbl OMNI-COTE ® and 125 lb/bbl CHEK-LOSS ®; added 12 lb/bbl of slurry (equivalent to 10 lb/bbl CHEK-LOSS) to base mud.




**LCM blend prepared by mixing 60% by weight MIL-GRAPHITE, 35% CHEK-LOSS ®, 2.5% WITCO 90 FLAKE and 2.5% INDUSTRENE R FLAKE.




***LCP supplied by Environmental Drilling Technology (Tulsa, OK).








[0076]

5





TABLE 5








Performance of KWIK-SEAL Fine compared


to CHEK-LOSS ® Coarse















Materials:












UNOCAL ECO-FLOW
1.0
1.0
1.0
1.0
1.0


Field Sample


(FSR 4341d), bbl


CHEK-LOSS ® Coarse,

10





lb/bbl


CHEK-LOSS ® Coarse


10




Retsch ground*,


lb/bbl


KWIK-SEAL Fine,



10



lb/bbl


KWIK-SEAL Fine




10


Retsch ground*,


lb/bbl


Stirred 30 min


Rolled 16 hr,


150° F.







Properties:












Electrical
1470
900
580
1280
1100


stability, volt


600 rpm rdg,
126
150
160
134
145


120° F.


300 rpm rdg
72
85
90
77
83


200 rpm rdg
53
63
67
58
61


100 rpm rdg
32
38
41
37
37


  6 rpm rdg
8
12
12
10
11


  3 rpm rdg
7
11
11
8
10


Plastic viscosity,
54
65
70
57
62


cp


Yield point,
18
20
20
20
21


lb/100 ft2


10-sec gel,
10
12
12
12
12


lb/100 ft2


10-min gel,
12
14
16
14
14


lb/100 ft2


Particle Size


Analyses of


Ground LCM additives


by Malvern:


D (v, 0.1)


12.96

15.11


D (v, 0.5)


100.9

99.4


D (v, 0.9)


335.8

369






Notes:




*LCM additives ground by Retsch apparatus








[0077]

6





TABLE 6








PPA STUDY - Evaluation of KWIK-SEAL ® Fine


compared to CHEK-LOSS ® Coarse in a laboratory


prepared 12 lb/gal SYN-TEQ ® fluid





















Materials








Lab-Prepared Base
1.0
1.0
1.0
1.0
1.0
1.0


Mud*, bbl


CHEK-LOSS ®, lb/bbl

10






CHEK-LOSS ® Coarse,


10


lb/bbl


CHEK-LOSS ® Coarse



10




Retsch ground**,


lb/bbl


KWIK-SEAL ® Fine,




10



lb/bbl


KWIK-SEAL ® Fine





10


Retsch ground**,


lb/bbl


Stirred 30 min


Rolled 16 hr,


150° F.







Properties













Electrical
1000
440
600
475
750
700


stability, volt


600 rpm rdg,
113
120
114
118
94
112


120° F.


300 rpm rdg
73
75
76
75
60
70


200 rpm rdg
58
59
60
59
45
53


100 rpm rdg
40
42
43
43
32
36


  6 rpm rdg
17
17
17
17
14
15


  3 rpm rdg
15
15
15
15
12
13


Plastic
40
45
38
43
34
42


viscosity, cp


Yield point,
33
30
38
32
26
28


lb/100 ft2


10-sec gel,
17
17
17
17
14
15


lb/100 ft2


10-min gel,
19
19
19
19
16
18


lb/100 ft2


PPA (90-micron,


250° F.)


Initial spurt
4.2
3.0
3.0
3.4
2.8
3.2


loss, ml


Total loss, ml
8.2
5.8
6.6
7.0
5.6
4.8






Notes:




*Base mud composition: 0.629 bbl ISO-TEQ ®, 12 lb OMNI-MUL ®, 0.15 bbl water, 8 lb/bbl CARBO-GEL ®, 18 lb calcium chloride, 239 lb/bbl MIL-BAR ®




**LCM additives ground by Retsch apparatus








[0078] From the foregoing, it was concluded that the intrinsic affinity of cellulosic fibers for water was the cause of the influence of these fibers on electrical stability. Decreased electrical stability values were attributable to swollen, hydrated fibers coming into contact with the electrical stability meter probe. The magnitude of the phenomenon was related to the amount of available water—i.e. the more water, the lower the value. Therefore, the reduction in electrical stability increased as oil/water ratios decreased. Water wetting of solids was never observed in the test fluids. The bar chart of FIG. 1 summarizes the variety of LCM effects upon electrical stability. Particulate LCMs such as MIL-CARB® had no effect. Mud property data is presented in the foregoing Tables, and in FIG. 2.


[0079] The following are oil mud evaluations detailing routine analytical results of submitted field mud samples used in the test matrices.
7TABLE 7Sample:ASample Used For:DrillingMud System:Syn-TeqDepth taken, feet:14800External Phase-Oil:Iso-S G, Weight Material:4.2TeqMud Weight, lbm/gal:17.1Density of Oil,6.6lbm/gal:Specific Gravity2.05Excess Lime, lbm/bbl1.04of Mud:Rheologies @, ° F.:150Total Calcium, mg/L12000mud600 rpm:98Total Chlorides, mg/L26000mud300 rpm:58CaCl2, mg/L mud40820200 rpm:44CaCl2, lbm/bbl of14.29mud100 rpm:28CaCl2, mg/L402,797  6 rpm:8CaCl2, % by weight31.2  3 rpm:7Brine Density, g/ml1.29Plastic Viscosity,40Corrected Brine, %10.1cPs:by vol.Yield Point, lbf/18Corrected Solids, %38.9100 ft2:by vol.Initial Gel, lbf/9Average Solids3.90100 ft2:Density,g/ml10 min Gel, lbf/12Weight Material, %31.3100 ft2:by vol.30 min Gel, lbf/13Weight Material,460.0100 ft2:lbm/bblAPI, mls/30 mins:Low Gravity Solids, %7.6by vol.HT-HP Temp, ° F.:300Low Gravity Solids,70.3lbm/bblHT-HP, mls/30 mins:2.2Oil:Water Ratio =15.0WaterPom, mls/1 ml mud:0.8Oil:Water Ratio =85.0OilAgN03, mls/1 ml mud:2.6Corrected Water16.6RatioEDTA, mls/1 ml mud:3Corrected Oil83.4RatioES, volts:1200Solids, % by vol.:40Water, % by vol.:9Oil, % by vol.:51


[0080]

8








TABLE 8













Sample:
E



Sample Used For:
Drilling



Mud System:
ECOFLOW 200



Depth taken, feet:














External Phase-Oil:
Eco-
S G, Weight Material:
4.2



flow




Mud Weight, lbm/gal:
16.6
Density of Oil,
6.6




lbm/gal:


Specific Gravity
2.00
Excess Lime, lbm/bbl
3.51


of Mud:


Rheologies @, ° F.:
150
Total Calcium,
11200




mg/L mud


600 rpm:
82
Total Chlorides,
24000




mg/L mud


300 rpm:
47
CaCl2, mg/L mud
37680


200 rpm:
35
CaCl2, lbm/bbl
13.19




of mud


100 rpm:
22
CaCl2, mg/L
530,455


  6 rpm:
6
CaCl2, % by weight
38.6


  3 rpm:
5
Brine Density, g/ml
1.38


Plastic Viscosity,
35
Corrected Brine, %
7.1


cPs:

by vol.


Yield Point, lbf/
12
Corrected Solids, %
39.9


100 ft2:

by vol.


Initial Gel, lbf/
7
Average Solids
3.71


100 ft2:

Density, g/ml


10 min Gel, lbf/
11
Weight Material, %
27.2


100 ft2:

by vol.


30 min Gel, lbf/
11
Weight Material,
399.4


100 ft2:

lbm/bbl


API, mls/30 mins:

Low Gravity Solids, %
12.7




by vol.


HT-HP Temp, ° F.:

Low Gravity Solids,
118.1




lbm/bbl


HT-HP, mls/30 mins:

Oil:Water Ratio =
10.2




Water


Pom, mls/1 ml mud:
2.7
Oil:Water Ratio =
89.8




Oil


AgN03, mls/1 ml
2.4
Corrected Water
11.8


mud:

Ratio


EDTA, mls/1 ml mud:
2.8
Corrected Oil
88.2




Ratio


ES, volts:
1360


Solids, % by vol.:
41


Water, % by vol.:
6


Oil, % by vol.:
53










[0081]

9








TABLE 9













Sample Number:
E



Sample Used For:
Drilling



Mud System:
Syn-Teq



Depth taken, feet:














External Phase-Oil:
Eco-
S G, Weight Material:
4.2



Flow 200




Mud Weight, lbm/gal:
17.0
Density of Oil,
6.5




lbm/gal:


Specific Gravity
2.04
Excess Lime,
5.46


of Mud:

lbm/bbl


Rheologies @, ° F.:
150
Total Calcium,
14800




mg/L mud


600 rpm:
89
Total Chlorides,
30000




mg/L mud


300 rpm:
52
CaCl2, mg/L mud
47100


200 rpm:
38
CaCl2, lbm/bbl
16.48




of mud


100 rpm:
25
CaCl2, mg/L
530,455


  6 rpm:
7
CaCl2, % by weight
38.6


  3 rpm:
6
Brine Density,
1.38




g/ml


Plastic Viscosity,
37
Corrected Brine, %
8.9


cPs:

by vol.


Yield Point, lbf/
15
Corrected Solids, %
38.1


100 ft2:

by vol.


Initial Gel, lbf/
8
Average Solids
3.94


100 ft2:

Density, g/ml


10 min Gel, lbf/
12
Weight Material, %
31.7


100 ft2:

by vol.


30 min Gel, lbf/
13
Weight Material,
466.6


100 ft2:

lbm/bbl


API, mls/30 mins:

Low Gravity Solids, %
6.4




by vol.


HT-HP Temp, ° F.:
300
Low Gravity Solids,
59.1




lbm/bbl


HT-HP, mls/30 mins:
2
Oil:Water Ratio =
12.4




Water


Pom, mls/1 ml mud:
4.2
Oil:Water Ratio =
87.6




Oil


AgN03, mls/1 ml mud:
3
Corrected Water
14.3




Ratio


EDTA, mls/1 ml mud:
3.7
Corrected Oil
85.7




Ratio


ES, volts:
1420


Solids, % by vol.:
39.5


Water, % by vol.:
7.5


Oil, % by vol.:
53











EXAMPLE 2

[0082] The following LCM's were obtained from Grinding & Sizing Co. labeled as: “Wood Fiber” (pine), “Grape Pumice”, “Pith”, “Furfural” and “Total Control” (ground rubber). Ground coconut shell was obtained from Reade Co. in 325 mesh size and 80-325 mesh size ( “Reade 325F” and “Reade 325/80,” respectively).


[0083] Equipment


[0084] 1. Prince Castle mixer


[0085] 2. Fann viscometer, Model 35A


[0086] 3. Thermometer, dial, 0-220° F.


[0087] 4. Balance with precision of 0.01 g


[0088] 5. Sieves (conforming to ASTM E11 requirements)


[0089] 6. Roller oven, 150-250±5° F. (66-121±3° C.)


[0090] 7. Spatula


[0091] 8. Timer: interval, mechanical or electrical, precision of 0.1 minute


[0092] 9. Jars (approximately 500 ml capacity) with sealing lids


[0093] 10. Heating cup, OFI, 115 volt


[0094] 11. Particle Plugging Apparatus


[0095] 12. Aloxite disks


[0096] 13. Malvern Mastersizer


[0097] PROCEDURES


[0098] The following INTEQ Fluids Laboratory procedures were used


[0099] Recommended Practice Standard Procedure for Field Testing Oil-Based Drilling Fluids, API Recommended Practice 13B-2, Third Edition, February 1998


[0100] Recommended Practice Standard Procedure for Field Testing Water-Based Drilling Fluids, API Recommended Practice 13B-1, Second Edition, September 1997


[0101] Instrumentation Manual for Malvern Mastersizer


[0102] The following results were observed:
10TABLE 10Evaluation of Various Fibrous LCM Additives from Grinding& Sizing Co., Inc., as compared to CHEK-LOSSMaterials:Field Mud FSR No. 4502, bbl1.01.01.01.01.01.01.0CHEK-LOSS, lb10Wood Fiber, lb10Grape Pumice, lb10Pith, lb10Furfural, lb10Total Control, lb10Stirred 15 min; rolled 16 hr, 150° F.Properties:600 rpm rdg at 120° F.91119114100108108107300 rpm rdg52696660646463200 rpm rdg38514844474746100 rpm rdg24313028303028  6 rpm rdg7888888  3 rpm rdg5666666Plastic viscosity, cp39504840444444Yield point, lb/100 sq ft1319182020201910-sec gel, lb/100 sq ft899999910-min gel, lb/100 sq ft11121212121212Electrical stability, volt750300350670540490590Pom, mls/1 ml mud1.61.551.55Particle plugging apparatus results,(300° F., 1000 psi, 90-micron)Spurt loss, ml3.04.82.0Final total loss, ml5.07.22.8


[0103] Oil-Mud Sample Evaluation Report (FSR No. 4502)
11External Phase-Eco-S G, Weight Material:4.2Oil:flowMud Weight,15.3Density of Oil, lbm/gal:6.6lbm/gal:Specific Gravity1.84Excess Lime, lbm/bbl1.95of Mud:Rheological150Total Calcium, mg/L mud10400Properties, ° F.:600 rpm:60Total Chlorides,22000mg/L mud300 rpm:35CaCl2, mg/L mud34540200 rpm:26CaCl2, lbm/bbl of mud12.09100 rpm:17CaCl2, mg/L347,539  6 rpm:5CaCl2, % by weight27.7  3 rpm:4Brine Density, g/ml1.25Plastic25Corrected Brine, %9.9Viscosity,by vol.cPs:Yield Point,10Corrected Solids, %35.1lbf/100 ft2:by vol.Initial Gel,7Average Solids3.65lbf/100 ft2:Density, g/ml10 min Gel,10Weight Material, %22.6lbf/100 ft2:by vol.30 min Gel,10Weight Material,331.5lbf/100 ft2:lbm/bblAPI, mls/30 mins:Low Gravity Solids, %12.5by vol.HT-HP Temp, ° F.:Low Gravity Solids,116.0lbm/bblHT-HP, mls/30Oil:Water Ratio =14.1mins:WaterPom, mls/11.5Oil:Water Ratio =85.9ml mud:OilAgN03, mls/12.2Corrected Water Ratio15.3ml mud:EDTA, mls/12.6Corrected Oil Ratio84.7ml mud:ES, volts:700Solids, % by36vol.:Water, % by vol.:9Oil, % by vol.:55


[0104]

12





TABLE 11








Evaluation of Grinding & Sizing Co. Grape Pumice, as compared


to CHEK-LOSS, in a Solids-Laden Oil-Based Field Mud

















Materials:












Field Mud (FSR No. 4522), bbl
1.0
1.0
1.0



CHEK-LOSS, lb

10




Grape Pumice, lb


10



Stirred 15 min; rolled 16 hr, 150° F.









Properties:












600 rpm rdg at 120° F.
150
190
150



300 rpm rdg
81
104
80



200 rpm rdg
58
72
56



100 rpm rdg
32
42
31



  6 rpm rdg
5
7
5



  3 rpm rdg
4
5
4



Plastic viscosity, cp
69
86
70



Yield point, lb/100 sq ft
12
18
10



10-sec gel, lb/100 sq ft
7
8
7



10-min gel, lb/100 sq ft
23
27
24



Electrical stability, volt
620
350
585



Pom, mls/1 ml mud
1.0
1.0
1.0



Particle plugging apparatus results,



(300° F., 1000 psi, 90-micron)



Spurt loss, ml
4.6
5.2
2.8



Final total loss, ml
9.0
9.6
5.2











[0105]

13





TABLE 12








Evaluation of Reade Co. Ground Coconut Shell, as compared


to CHEK-LOSS, in a Solids-Laden Oil-Based Field Mud















Materials:











Field Mud (FSR No. 4522), bbl
1.0
1.0
1.0
1.0


CHEK-LOSS, lb

10




Reade 325F, lb


10



Reade 80/325, lb



10


Stirred 15 min; rolled 16 hr, 150° F.







Properties:











600 rpm rdg at 120° F.
150
190
173
185


300 rpm rdg
81
104
97
102


200 rpm rdg
58
72
72
75


100 rpm rdg
32
42
41
42


  6 rpm rdg
5
7
8
6


  3 rpm rdg
4
5
6
4


Plastic viscosity, cp
69
86
76
83


Yield point, lb/100 sq ft
12
18
21
19


10-sec gel, lb/100 sq ft
7
8
11
11


10-min gel, lb/100 sq ft
23
27
48
40


Electrical stability, volt
620
350
605
585


Pom, mls/1 ml mud
1.0
1.0

0.95


Particle plugging apparatus results,


(300° F., 1000 psi, 90-micron)


Spurt loss, ml
4.6
5.2

3.4


Final total loss, ml
9.0
9.6

6.6










[0106] The coconut materials had very minimal impact upon the electrical stability value of the base fluid. However, these materials appeared to be kilned, thus making them more characteristic as a particulate rather than a fiber. Resultant rheological properties were not satisfactory.


[0107] In Data Tables 11 and 12, Formula 4522 was the following:


[0108] Oil-Mud Sample Evaluation Report (FSR No. 4522)
14External Phase-Oil:DieselS G, Weight Material:4.2Mud Weight, lbm/gal:16.5Density of Oil, lbm/gal:7.1Specific Gravity of Mud:  1.98Excess Lime, lbm/bbl1.30Rheological Properties, ° F.:  150, 120Total Calcium, mg/L mud5200600 rpm:  96, 137Total Chlorides, mg/L mud9000300 rpm:  52, 75CaCl2, mg/L mud14130200 rpm:  36, 52CaCl2, lbm/bbl of mud4.95100 rpm:  21, 29CaCl2, mg/L150,804  6 rpm:  4, 5CaCl2, % by weight13.6  3 rpm:  3, 4Brine Density, g/ml1.11Plastic Viscosity, cPs:  44, 62Corrected Brine, % by vol.9.4Yield Point, lbf/100 ft2:  8, 13Corrected Solids, % by vol.39.1Initial Gel, lbf/100 ft2:  5, 6Average Solids Density, g/ml3.6710 min Gel, lbf/100 ft2:  21, 22Weight Material, % by vol.25.730 min Gel, lbf/100 ft2:  29, 30Weight Material, lbm/bbl377.4API, mls/30 mins:Low Gravity Solids, % by vol.13.5HT-HP Temp, ° F.:300   Low Gravity Solids, lbm/bbl124.8HT-HP, mls/30 mins: 9.2Oil:Water Ratio = Water14.9Pom, mls/1 ml mud:1 Oil:Water Ratio = Oil85.1AgN03, mls/1 ml mud: 0.9Corrected Water Ratio15.4EDTA, mls/1 ml mud: 1.3Corrected Oil Ratio84.6ES, volts:650   Solids, % by vol.:39.5Water, % by vol.:9 Oil, % by vol.:51.5


[0109]

15





TABLE 13








Evaluation of Grinding & Sizing Co. Grape Pumice, as compared


to CHEK-LOSS, in a Laboratory-Prepared Water-Based Mud

















Materials:












Lab-Prepared Mud (FSR No.
1.0
1.0
1.0



4423b), bbl



CHEK-LOSS, lb

10




Grape Pumice, lb


10



Stirred 15 min; rolled 16 hr, 150° F.









Properties:












600 rpm rdg at 120° F.
74
141
90



300 rpm rdg
40
80
52



200 rpm rdg
28
57
40



100 rpm rdg
17
35
25



  6 rpm rdg
3
9
8



  3 rpm rdg
2
7
6



Plastic viscosity, cp
24
61
38



Yield point, lb/100 sq ft
16
19
14



10-sec gel, lb/100 sq ft
6
14
14



10-min gel, lb/100 sq ft
23
38
44



pH
9.0
8.4
7.5



API filtrate, ml
0.6
0.4
0.4











[0110] In Data Table 13, Formulation 4423b was the following:
16Formulation (FSR 4423b)Water, bbl0.6MILGEL, lb4.0Soda Ash, lb1.0NEW-DRILL LV, lb0.5Sea salt, lb8.8MIL-PAC LV, lb1.0CHEMTROL X, lb6.0LIGCO, lb6.0TEQ-THIN, lb3.0SULFATROL, lb2.0Caustic Soda, lb2.5AQUA-MAGIC, % vol3.0ALL-TEMP, lb1.0Rev Dust, lb18.0MIL-BAR, lb450.0MIL-CARB, lb10.0CHECK-LOSS, lb3.0


[0111] Grape Pumice appears to fulfill the needed characteristic of being composed of more lignin rather than cellulose. Grape Pumice caused significantly less impact (5-10% decreases) upon electrical stability values, as compared to 50-60% decreases when adding CHEK-LOSS. Grape Pumice also induced less impact upon the plastic viscosities of the oil muds, as compared to CHEK-LOSS. Grape Pumice provided better PPA (particle plugging apparatus) results, as compared to CHEK-LOSS at test conditions of 300° F., 1000 psi differential, 90-micron aloxite disk.



EXAMPLE 3

[0112] The papermaking industry uses a measurement called the Water Retention Value (WRV), which gives the amount of water intimately associated with a given dry weight of wood pulp. This represents the capacity of fibers to swell in the presence of water. This value varies with the source of plant fibers (corn, peanut, walnut, almond, coconut, etc.). The paper industry wants more cellulose, less lignin. The need in this application is to choose a plant fiber source with a ratio of more lignin with less cellulose. Lignin, which serves as the “skeletal” structure for plants, is significantly less water-absorbent.


[0113] The following described procedure is a modification of the TAPPI 1991 UM-256 procedure used in the papermaking industry. Equipment used included:


[0114] 1. Prince Castle mixer


[0115] 2. Tachometer


[0116] 3. 500-ml glass jars with lids


[0117] 4. Deionized water


[0118] 5. Electronic balance


[0119] 6. Vacuum pump


[0120] 7. 2-liter Erlenmeyer flask


[0121] 8. Buchner funnel


[0122] 9. Whatman filter paper No. 41


[0123] An amount of 25 g test material was added to a glass jar. 250 ml of deionized water was then added. The slurry was sheared at 3000 rpm for 5 min. The glass jar was capped and rolled 16 hr at 150° F. After cooling, the jar contents was poured into an assembled Buchner funnel (using Whatman filter paper No. 41) fitted on a 2-liter Erlenmeyer flask, hooked to a vacuum pump. Filtration was conducted for two hours maximum. The Buchner funnel with test material content was removed from the flask and was weighed. Calculation of the WRV would be as follows:


[0124] (Buchner funnel with filter paper and retained wet test material minus Buchner funnel with wet paper) minus initial 25 g dry test material. Resultant value then divided by initial 25 g dry test material.


[0125] Results were, as follows:
17Weight ofWeight,filtered, wetTest MaterialgMaterial, gWRVBuchner funnel with wet602.2paperAbove with MIL-CARB630.828.60.144Above with Grape Pumice633.631.40.256Above with CHEK-LOSS727.8125.64.024Above with Mud-Liner745.0142.84.712Above with Liquid Casing715.0112.83.512


[0126] The Grape Pumice material appears to fulfill the needed characteristic of being composed of more lignin rather than cellulose.


[0127] Particle size analyses by Malvern Mastersizer instrumentation showed the Grape Pumice to be near-similar to CHEK-LOSS:
18Test MaterialD (v, 0.1)D (v, 0.5)D (v, 0.9)Grape Pumice16 μm69 μm166 μmCHEK-LOSS21 μm68 μm185 μm


[0128] As evident by this data, particle size distribution would not contribute to differentiating WRV between the two materials; Grape Pumice exhibits significantly less water absorbency, a characteristic favorable for application as a LCM in invert emulsion drilling fluids while not interfering with emulsion stability measurements.



EXAMPLE 4

[0129] The Grape Pumice material, being acidic, will lower pH levels in aqueous muds. A test was conducted by adding 10 lb Grape Pumice to a 1-bbl equivalent of deionized water. Resultant pH was 3.5. Blending 10 lb Grape Pumice with 0.2 lb soda ash kept the pH at 7.0.


[0130] Because of this concern, alkalinity levels were measured in the oil muds tested with Grape Pumice. There were no changes, thus the Grape Pumice seems to be preferentially oil-wetted.


[0131] Persons of ordinary skill in the art will recognize that many modifications may be made to the present invention without departing from the spirit and scope of the invention. The embodiment described herein is meant to be illustrative only and should not be taken as limiting the invention, which is defined in the claims.


Claims
  • 1. A method for maintaining electrical stability in an emulsion type drilling, drill-in, or completion fluid comprising lost circulation material (LCM), said method comprising: providing an initial fluid selected from the group consisting of an emulsion-type drilling, drill-in, or completion fluid, said initial fluid having effective rheology and fluid loss control properties; using a fibrous LCM in said initial fluid, said fibrous LCM consisting essentially of a quantity of high lignin lost circulation material (HLLCM), said fibrous HLLCM being effective to produce a treated fluid having effective rheology and fluid loss control properties; wherein said initial fluid exhibits a first electrical stability value and said treated fluid exhibits a second electrical stability value that is a maximum of 20% less than said first electrical stability value.
  • 2. The method of claim 1 wherein said second electrical stability value is a maximum of 18% less than said first electrical stability value.
  • 3. The method of claim 1 wherein second electrical stability value is a maximum of 15% less than said first electrical stability value.
  • 4. The method of claim 1 wherein said second electrical stability value is a maximum of 12% less than said first electrical stability value.
  • 5. The method of claim 1 wherein said fibrous HLLCM has a water retention value of about 1 or less.
  • 6. The method of claim 1 wherein said fibrous HLLCM has a water retention value of about 0.5 or less.
  • 7. The method of claim 1 wherein said fibrous HLLCM has a water retention value of about 0.3 or less.
  • 8. The method of claim 2 wherein said fibrous HLLCM has a water retention value of about 1 or less.
  • 9. The method of claim 2 wherein said fibrous HLLCM has a water retention value of about 0.5 or less.
  • 10. The method of claim 2 wherein said fibrous HLLCM has a water retention value of about 0.3 or less.
  • 11. A method for maintaining electrical stability in an emulsion type drilling, drill-in, or completion fluid comprising lost circulation material (LCM), said method comprising: providing an initial fluid selected from the group consisting of an invert emulsion drilling, drill-in, or completion fluid, said initial fluid having effective rheology and fluid loss control properties; using a fibrous LCM in said initial fluid, said fibrous LCM consisting essentially of a quantity of high lignin lost circulation material (HLLCM), said fibrous HLLCM being effective to produce a treated fluid having effective rheology and fluid loss control properties; wherein said initial fluid exhibits a first electrical stability value and said treated fluid exhibits a second electrical stability value that is a maximum of 20% less than said first electrical stability value.
  • 12. The method of claim 11 wherein said second electrical stability value is a maximum of 18% less than said first electrical stability value.
  • 13. The method of claim 11 wherein said second electrical stability value is a maximum of 15% less than said first electrical stability value.
  • 14. The method of claim 11 wherein said second electrical stability value is a maximum of 12% less than said first electrical stability value.
  • 15. The method of claim 11 wherein said fibrous HLLCM has a water retention value of about 1 or less.
  • 16. The method of claim 11 wherein said fibrous HLLCM has a water retention value of about 0.5 or less.
  • 17. The method of claim 11 wherein said fibrous HLLCM has a water retention value of about 0.3 or less.
  • 18. The method of claim 12 wherein said fibrous HLLCM has a water retention value of about 1 or less.
  • 19. The method of claim 12 wherein said fibrous HLLCM has a water retention value of about 0.5 or less.
  • 20. The method of claim 12 wherein said fibrous HLLCM has a water retention value of about 0.3 or less.
  • 21. The method of claim 11 wherein said HLLCM is selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from processing plant material into paper.
  • 22. A method for maintaining electrical stability in a drilling, drill-in, or completion fluid, said method comprising: providing an initial fluid selected from the group consisting of an emulsion type drilling, drill-in, or completion fluid having effective rheology and fluid loss control properties; and using as LCM in said initial fluid a fibrous HLLCM having a water retention value of about 1 or less, said HLLCM being effective to produce a treated fluid having effective rheology and fluid loss control properties.
  • 23. The method of claim 22 wherein said fibrous HLLCM has a water retention value of about 0.5 or less.
  • 24. The method of claim 22 wherein said fibrous HLLCM has a water retention value of about 0.3 or less.
  • 25. A method for maintaining electrical stability in a drilling, drill-in, or completion fluid, said method comprising: providing an initial fluid selected from the group consisting of invert emulsion drilling, drill-in, or completion fluids having effective rheology and fluid loss control properties; and using as LCM in said initial fluid a fibrous HLLCM having a water retention value of about 1 or less, said fibrous HLLCM being effective to produce a treated fluid having effective rheology and fluid loss control properties.
  • 26. The method of claim 25 wherein said LCM has a water retention value of about 0.5 or less.
  • 27. The method of claim 25 wherein said LCM has a water retention value of about 0.3 or less.
  • 28. A method for maintaining electrical stability in a drilling, drill-in, or completion fluid, said method comprising: providing an initial fluid selected from the group consisting of a emulsion type drilling, drill-in, or completion fluid, said initial fluid having effective rheology and fluid loss control properties; and using an LCM in said initial fluid, said LCM consisting essentially of grape pumice effective to produce a treated fluid having effective rheology and fluid loss control properties.
  • 29. A method for maintaining electrical stability in a drilling, drill-in, or completion fluid, said method comprising: providing an initial fluid selected from the group consisting of an invert emulsion drilling, drill-in, or completion fluid, said initial fluid having effective rheology and fluid loss control properties; and using an LCM in said initial fluid, said LCM consisting essentially of grape pumice effective to produce a treated fluid having effective rheology and fluid loss control properties.
  • 30. A treated emulsion type fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said emulsion type drilling fluid having effective rheology and fluid loss control properties and comprising a lost circulation material consisting essentially of an HLLCM, said wherein said emulsion type fluid exhibits a first electrical stability value and said treated emulsion type fluid exhibits a second electrical stability value that is a maximum of 20% less than said first electrical stability value.
  • 31. The treated emulsion type fluid of claim 30 wherein said second electrical stability value is a maximum of 18% less than said first electrical stability value.
  • 32. The treated emulsion type fluid of claim 30 wherein second electrical stability value is a maximum of 15% less than said first electrical stability value.
  • 33. The treated emulsion type fluid of claim 30 wherein said second electrical stability value is a maximum of 12% less than said first electrical stability value.
  • 34. The treated emulsion type fluid of claim 30 wherein said HLLCM has a water retention value of about 1 or less.
  • 35. The treated emulsion type fluid of claim 30 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 36. The treated emulsion type fluid of claim 30 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 37. The treated emulsion type fluid of claim 31 wherein said HLLCM has a water retention value of about 1 or less.
  • 38. The treated emulsion type fluid of claim 31 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 39. The treated emulsion type fluid of claim 31 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 40. The treated emulsion type fluid of claim 30 wherein said HLLCM is selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from processing plant material into paper.
  • 41. The treated emulsion type fluid of claim 30 wherein said HLLCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 42. A treated invert emulsion fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said invert emulsion fluid having effective rheology and fluid loss control properties and comprising a lost circulation material consisting essentially of an HLLCM, said wherein said invert emulsion fluid exhibits a first electrical stability value and said treated emulsion type fluid exhibits a second electrical stability value that is a maximum of 20% less than said first electrical stability value.
  • 43. The treated emulsion type fluid of claim 42 wherein said second electrical stability value is a maximum of 18% less than said first electrical stability value.
  • 44. The treated emulsion type fluid of claim 42 wherein second electrical stability value is a maximum of 15% less than said first electrical stability value.
  • 45. The treated emulsion type fluid of claim 42 wherein said second electrical stability value is a maximum of 12% less than said first electrical stability value.
  • 46. The treated emulsion type fluid of claim 42 wherein said HLLCM has a water retention value of about 1 or less.
  • 47. The treated emulsion type fluid of claim 42 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 48. The treated emulsion type fluid of claim 42 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 49. The treated emulsion type fluid of claim 43 wherein said HLLCM has a water retention value of about 1 or less.
  • 50. The treated emulsion type fluid of claim 43 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 51. The treated emulsion type fluid of claim 43 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 52. The treated emulsion type fluid of claim 42 wherein said HLLCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 53. A treated emulsion type fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said fluid having effective rheology and fluid loss control properties and consisting essentially of an LCM having a water retention value of about 1 or less.
  • 54. The treated emulsion type fluid of claim 53 wherein said LCM has a water retention value of about 0.5 or less.
  • 55. The treated emulsion type fluid of claim 54 wherein said LCM has a water retention value of about 0.3 or less.
  • 56. The treated emulsion type fluid of claim 53 wherein said LCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 57. A treated invert emulsion fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said fluid having effective rheology and fluid loss control properties and consisting essentially of an LCM having a water retention value of about 1 or less.
  • 58. The treated emulsion type fluid of claim 57 wherein said LCM has a water retention value of about 0.5 or less.
  • 59. The treated emulsion type fluid of claim 57 wherein said LCM has a water retention value of about 0.3 or less.
  • 60. The treated emulsion type fluid of claim 57 wherein said LCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 61. A treated emulsion type fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said fluid having effective rheology and fluid loss control properties and comprising a fibrous LCM, said fibrous LCM consisting essentially of materials selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from the processing of plant material into paper.
  • 62. The treated emulsion type fluid of claim 61 wherein said LCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 63. A treated emulsion type fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said fluid having effective rheology and fluid loss control properties and comprising a fibrous LCM consisting essentially of grape pumice.
  • 64. The treated emulsion type fluid of claim 63 wherein said fibrous LCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 65. A treated invert emulsion fluid selected from the group consisting of a drilling, drill-in, or completion fluid, said fluid having effective rheology and fluid loss control properties and comprising a fibrous LCM consisting essentially of grape pumice.
  • 66. The treated invert emulsion fluid of claim 65 wherein said fibrous LCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 67. A spotting pill comprising from about 1 to about 100 ppb of an HLLCM and a carrier liquid, wherein a given emulsion type fluid exhibits a first electrical stability value absent said spotting pill and said given emulsion type fluid comprising said spotting pill exhibits a second electrical stability value that is a maximum of 20% less than said first electrical stability value.
  • 68. The spotting pill of claim 67 wherein said second electrical stability value is a maximum of 18% less than said first electrical stability value.
  • 69. The spotting pill of claim 67 wherein second electrical stability value is a maximum of 15% less than said first electrical stability value.
  • 70. The spotting pill of claim 67 wherein said second electrical stability value is a maximum of 12% less than said first electrical stability value.
  • 71. The spotting pill of claim 67 wherein said HLLCM has a water retention value of about 1 or less.
  • 72. The spotting pill of claim 67 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 73. The spotting pill of claim 67 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 74. The spotting pill of claim 68 wherein said HLLCM has a water retention value of about 1 or less.
  • 75. The spotting pill of claim 68 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 76. The spotting pill of claim 68 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 77. The spotting pill of claim 67 wherein said HLLCM is selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from processing plant material into paper.
  • 78. The spotting pill of claim 67 comprising from about 5 to about 50 ppb of said HLLCM.
  • 79. The spotting pill of claim 67 wherein said carrier liquid is selected from the group consisting of polyalkylene oxides and copolymers thereof, polyalkyleneoxide glycol ethers, glycols, polyglycols, tripropylene glycol bottoms, and combinations thereof.
  • 80. The spotting pill of claim 67 wherein said carrier liquid is selected from the group consisting of ethylene glycols, diethylene glycols, triethylene glycols, tetraethylene glycols, propylene glycols, dipropylene glycols, tripropylene glycols, tetrapropylene glycols, polyethylene oxides, polypropylene oxides, copolymers of polyethylene oxides and polypropylene oxides, polyethylene glycol ethers, polypropylene glycol ethers, polyethylene oxide glycol ethers, polypropylene oxide glycol ethers, and polyethylene oxide/polypropylene oxide glycol ethers.
  • 81. The spotting pill of claim 67 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 82. The spotting pill of claim 68 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 83. The spotting pill of claim 69 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 84. The spotting pill of claim 70 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 85. A spotting pill comprising from about 1 to about 100 ppb of an HLLCM and a carrier liquid, wherein a given invert emulsion fluid exhibits a first electrical stability value absent said spotting pill and said given invert emulsion fluid comprising said spotting pill exhibits a second electrical stability value that is a maximum of 20% less than said first electrical stability value.
  • 86. The spotting pill of claim 85 wherein said second electrical stability value is a maximum of 18% less than said first electrical stability value.
  • 87. The spotting pill of claim 85 wherein second electrical stability value is a maximum of 15% less than said first electrical stability value.
  • 88. The spotting pill of claim 85 wherein said second electrical stability value is a maximum of 12% less than said first electrical stability value.
  • 89. The spotting pill of claim 85 wherein said HLLCM has a water retention value of about 1 or less.
  • 90. The spotting pill of claim 85 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 91. The spotting pill of claim 85 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 92. The spotting pill of claim 86 wherein said HLLCM has a water retention value of about 1 or less.
  • 93. The spotting pill of claim 86 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 94. The spotting pill of claim 86 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 95. The spotting pill of claim 85 wherein said HLLCM is selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from processing plant material into paper.
  • 96. The spotting pill of claim 85 comprising from about 5 to about 50 ppb of said HLLCM.
  • 97. The spotting pill of claim 85 wherein said carrier liquid is selected from the group consisting of polyalkylene oxides and copolymers thereof, polyalkyleneoxide glycol ethers, glycols, polyglycols, tripropylene glycol bottoms, and combinations thereof.
  • 98. The spotting pill of claim 85 wherein said carrier liquid is selected from the group consisting of ethylene glycols, diethylene glycols, triethylene glycols, tetraethylene glycols, propylene glycols, dipropylene glycols, tripropylene glycols, tetrapropylene glycols, polyethylene oxides, polypropylene oxides, copolymers of polyethylene oxides and polypropylene oxides, polyethylene glycol ethers, polypropylene glycol ethers, polyethylene oxide glycol ethers, polypropylene oxide glycol ethers, and polyethylene oxide/polypropylene oxide glycol ethers.
  • 99. The spotting pill of claim 85 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 100. The spotting pill of claim 86 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 101. The spotting pill of claim 87 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 102. The spotting pill of claim 88 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 103. A spotting pill comprising from about 1 to about 100 ppb of an HLLCM and a carrier liquid, wherein said HLLCM has a water retention value of about 1 or less.
  • 104. The spotting pill of claim 103 comprising from about 5 to about 50 ppb of an HLLCM and a carrier liquid.
  • 105. The treated emulsion type fluid of claim 103 wherein said HLLCM has a water retention value of about 0.5 or less.
  • 106. The treated emulsion type fluid of claim 103 wherein said HLLCM has a water retention value of about 0.3 or less.
  • 107. The treated emulsion type fluid of claim 103 wherein said LCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 108. The spotting pill of claim 103 wherein said carrier liquid is selected from the group consisting of polyalkylene oxides and copolymers thereof, polyalkyleneoxide glycol ethers, glycols, polyglycols, tripropylene glycol bottoms, and combinations thereof.
  • 109. The spotting pill of claim 103 wherein said carrier liquid is selected from the group consisting of ethylene glycols, diethylene glycols, triethylene glycols, tetraethylene glycols, propylene glycols, dipropylene glycols, tripropylene glycols, tetrapropylene glycols, polyethylene oxides, polypropylene oxides, copolymers of polyethylene oxides and polypropylene oxides, polyethylene glycol ethers, polypropylene glycol ethers, polyethylene oxide glycol ethers, polypropylene oxide glycol ethers, and polyethylene oxide/polypropylene oxide glycol ethers.
  • 110. The spotting pill of claim 103 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 111. The spotting pill of claim 104 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 112. The spotting pill of claim 105 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 113. The spotting pill of claim 106 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 114. A spotting pill comprising from about 1 to about 100 ppb of an HLLCM and a carrier liquid, wherein said HLLCM consists essentially of materials selected from the group consisting of grape pumice, bulrush plants, and lignin byproducts from the processing of plant material into paper.
  • 115. The spotting pill of claim 114 comprising from about 5 to about 50 ppb of said HLLCM.
  • 116. The spotting pill of claim 114 wherein said LCM comprises a particle size distribution of from about 10 μm to about 200 μm.
  • 117. The spotting pill of claim 114 wherein said carrier liquid is selected from the group consisting of polyalkylene oxides and copolymers thereof, polyalkyleneoxide glycol ethers, glycols, polyglycols, tripropylene glycol bottoms, and combinations thereof.
  • 118. The spotting pill of claim 114 wherein said carrier liquid is selected from the group consisting of ethylene glycols, diethylene glycols, triethylene glycols, tetraethylene glycols, propylene glycols, dipropylene glycols, tripropylene glycols, tetrapropylene glycols, polyethylene oxides, polypropylene oxides, copolymers of polyethylene oxides and polypropylene oxides, polyethylene glycol ethers, polypropylene glycol ethers, polyethylene oxide glycol ethers, polypropylene oxide glycol ethers, and polyethylene oxide/polypropylene oxide glycol ethers.
  • 119. The spotting pill of claim 114 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 120. The spotting pill of claim 115 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 121. A spotting pill comprising from about 1 to about 100 ppb grape pumice and a carrier liquid.
  • 122. The spotting pill of claim 121 comprising from about 5 to about 50 ppb of said grape pumice.
  • 123. The spotting pill of claim 121 wherein said carrier liquid is selected from the group consisting of polyalkylene oxides and copolymers thereof, polyalkyleneoxide glycol ethers, glycols, polyglycols, tripropylene glycol bottoms, and combinations thereof.
  • 124. The spotting pill of claim 122 wherein said carrier liquid is selected from the group consisting of polyalkylene oxides and copolymers thereof, polyalkyleneoxide glycol ethers, glycols, polyglycols, tripropylene glycol bottoms, and combinations thereof.
  • 125. The spotting pill of claim 121 wherein said carrier liquid is selected from the group consisting of ethylene glycols, diethylene glycols, triethylene glycols, tetraethylene glycols, propylene glycols, dipropylene glycols, tripropylene glycols, tetrapropylene glycols, polyethylene oxides, polypropylene oxides, copolymers of polyethylene oxides and polypropylene oxides, polyethylene glycol ethers, polypropylene glycol ethers, polyethylene oxide glycol ethers, polypropylene oxide glycol ethers, and polyethylene oxide/polypropylene oxide glycol ethers.
  • 126. The spotting pill of claim 122 wherein said carrier liquid is selected from the group consisting of ethylene glycols, diethylene glycols, triethylene glycols, tetraethylene glycols, propylene glycols, dipropylene glycols, tripropylene glycols, tetrapropylene glycols, polyethylene oxides, polypropylene oxides, copolymers of polyethylene oxides and polypropylene oxides, polyethylene glycol ethers, polypropylene glycol ethers, polyethylene oxide glycol ethers, polypropylene oxide glycol ethers, and polyethylene oxide/polypropylene oxide glycol ethers.
  • 127. The spotting pill of claim 121 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 128. The spotting pill of claim 122 wherein said carrier liquid is selected from the group consisting of ethylene glycol, tripropylene glycol bottoms, and combinations thereof.
  • 129. A spotting pill comprising from about 1 to about 100 ppb of an HLLCM and a carrier liquid comprising tripropylene glycol bottoms.
  • 130. The spotting pill of claim 129 comprising from about 5 to about 50 ppb of said HLLCM.
  • 131. A spotting pill comprising from about 1 to about 100 ppb grape pumice and a carrier liquid comprising tripropylene glycol bottoms.
  • 132. The spotting pill of claim 131 comprising from about 5 to about 50 ppb of said grape pumice.
Parent Case Info

[0001] The present application claims the benefit of U.S. Provisional Application Serial No. 60/315,761, filed Aug. 29, 2001, pending.

Provisional Applications (1)
Number Date Country
60315761 Aug 2001 US