Information
-
Patent Grant
-
6585115
-
Patent Number
6,585,115
-
Date Filed
Tuesday, November 28, 200024 years ago
-
Date Issued
Tuesday, July 1, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Walsh; Donald P.
- Miller; Jonathan R
Agents
- Madan, Mossman & Sriram, P.C.
-
CPC
-
US Classifications
Field of Search
US
- 207 3
- 207 17
- 207 73
- 207 281
- 175 206
- 175 207
- 175 213
-
International Classifications
-
Abstract
An apparatus and method for removing and recovering up to 98 percent of the residual drilling mud and fluids from drill cuttings for reuse and storing the drill cuttings in a relatively dry state thereby reducing cuttings volume requirements for storage and transport thereby reducing constipation of the drilling process due to disposal congestion. The present invention further provides methods for collecting and transferring drill cuttings in either dry or wet states to various locations on or adjacent the rig for processing, containerization, transport and disposal, thereby reducing handling and contamination thus simplifying recycling while reducing cost.
Description
SPECIFICATION
Field of the Invention
This is a continuation application of United Kingdom application 9913567.5 filed in the U.K., Jun. 11, 1999, now pending. Priority is claimed to PCT application No. GB 99/04097 filed Dec. 10, 1999.
This invention relates generally to handling of waste materials especially particulate solids. A method of transferring such materials from one location to another, and an apparatus suitable for performing the method, is described hereinafter. The invention finds particular utility in the oil and gas industry for disposal of well or drill cuttings (“hereinafter cuttings”) discharged from the solids control system on a well drilling site.
BACKGROUND OF THE INVENTION
Cuttings are typically pieces of rock, which have been chipped, ground or scraped out of a formation by a drill bit. Various types of drill cutting tools_are in use for this purpose and the invention hereinafter described is not limited to use of any particular type.
The drilling operation is conducted several hundred meters below the operation control point, which means that performance of the drill bit is critical to the operation. The effectiveness of the drill bit during a drilling operation relies upon the continual removal of cuttings; otherwise the drill would rapidly foul up due to accumulation of cuttings. Therefore, the cuttings are normally removed by delivery of a drilling fluid (often referred to as “drilling mud”) down to and around the drill bit in a recirculated manner by use of the drill string and annulus casing well established in the industry.
Accordingly the cuttings are commonly separated from the drilling fluid by devices such as a shale shaker, which captures cuttings and large solids from the drilling fluid during the circulation thereof. Basically, such a device has a sloping, close mesh, screen over which fluid returning from the hole being drilled passes. The screen may be typically of from 200×200 down to 30×30 mesh and is vibrated to facilitate separation of the majority of fluids from the solids. The solids captured on the screen travel down the sloping surface to be collected in the shaker ditch or cuttings trough. It is also desirable to recover as much of the expensive drilling fluids as possible. Therefore, other devices, which play a role in the separation of solids from drilling fluids, include cyclone separators, and centrifuges. The cuttings discharged from the shakers, cyclone's and centrifuges that are collected in the shaker ditch or cuttings trough are still highly contaminated with the drilling fluids and therefore form a slurry or heavy sludge. The slurry or sludge is very difficult to move or otherwise transfer in any conventional manner.
In some cases the cuttings slurry may be discharged directly into a cuttings box where space permits or vacuum collected, which under current practice means that the cuttings are sucked from the cuttings ditch or trough, by an applied vacuum, directly into a cuttings box for transport to an approved disposal site for re-claimation suggested in GB-A-2 286 615. However, in some cases in order to facilitate removal of the cuttings, a collection hopper may be used which allows a particular ground clearance typically of about 4 meters whereby the cuttings are discharged from the hopper by free-fall into open cuttings containers.
It is also proposed there to include another trough for intermediate collection of cuttings. A screw conveyor for lateral displacement of cuttings from beneath the intermediate trough is described. The screw conveyor pushes the cuttings, which fall into it from the trough towards a discharge trap door that opens under the weight of the cuttings to periodically allow the cuttings to fall into the holding tank.
The intermediate trough described remains under the influence of the suction pump to continue delivery of recovered fluid to a recycle system, whilst the screw conveyor below the trough shifts cuttings towards the trap door.
In a more recent operational system a vacuum cuttings hopper is provided including, a helical screw therein on a vertically arranged shaft driven by an overhead motor assists the delivery of the solids to the free-fall outlet for collection below the hopper, The cuttings are further subjected to compression by the helical screw prior to discharge thus extracting and recovering a substantial amount of the remaining fluids in the slurry. The extracted fluid is then withdrawn through a perforated casing around the screw under the action of a pump.
The problems associated with cuttings handling for disposal are familiar to all workers on a drilling installation and include the need for the presence of several storage containers to handle the volumes of cuttings produced and the time demands upon the installation's crane devoted to the shifting of a filled container to substitute an empty container close to the shaker station. This container “shuttling” routine is not only absorbing useful operational time for the crane but also presents additional physical hazards to workers involved in other tasks in close proximity to the cuttings containers. Furthermore, the cuttings recovery equipment and the containers themselves are usually accessed by workers scaling ladders, or scaffolding or the like staging up to heights often approaching 5 or 6 meters or thereabouts in order to open container lids or service the cuttings handling equipment. Of necessity the containers themselves must be sited close to the cuttings shaker station and be accessible by the crane. These factors have an impact on use of deck space, personnel mobility, and other task completion operations around the deck.
Further the filling and relocation of cuttings containers is dictated by the volume of cuttings being produced by the drilling operation in any given period of time. Therefore, it is essential that the cuttings handling apparatus and its methods of operation be capable of handling the volumes required to maintain production.
An object of the present invention is to provide improvements in cuttings handling for disposal and recovery of reusable drilling fluids and muds from the drill cuttings slurry thereby reducing cost of disposal and recycling. A
object fulfilled by aspects of the invention to be described hereinafter is to provide a drill cuttings recovery system of more compact or efficient design.
A still further object is to provide a more flexible disposal method allowing the operator greater degree of freedom in the options for handling the cuttings prior to disposal.
Generally the invention seeks to provide a system and method for handling of cuttings, which offers an improved alternative to current handling systems.
The invention, according to a first aspect, provides a method for handling cuttings that includes providing a system utilizing a screw pump to remove the cuttings from the cuttings trough and disperse them through a piping system to various disposal points.
The invention according to another aspect, provides a method for handling of cuttings, which method comprises providing a vessel adapted to sustain a reduced internal pressure with respect to external ambient atmospheric pressure, and external pumping means, said vessel and pumping means being operationally connected by means including a conduit, collecting cuttings from a drilling fluid/cuttings separation device in said vessel, removing cuttings from said vessel by means of said pumping means through said conduit whilst maintaining a reduced pressure, and selectively delivering removed cuttings by means of pumping to at least one of a variety of disposal points including a cuttings re-injection apparatus, removable transportable cuttings containers including a barge or the like for shipping to a remote disposal site.
According to another aspect of the invention there is provided an apparatus for handling of cuttings, comprising a vessel adapted to sustain a reduced internal pressure with respect to external ambient atmospheric pressure, and further provide a means for extracting fluids, the apparatus also having operationally connected thereto, external pumping means capable of maintaining the reduced internal pressure and removing the separated fluids while discharging the cuttings to a variety of storage containers or to a cuttings re-injection apparatus.
In accordance with still another aspect of the invention a centrifugal dryer is provided for drying the drill cuttings prior to distribution, by way of a blowers and or vacuum systems, to various holding containers located on or near the rig. This drying process removes the fluids and thereby allows all of the cuttings being produced by the drilling operation to be contained on the rig for longer periods of time prior to removal or re-injection.
Significantly, according to the invention, the proposed use of the pumping means for not only initially collecting the cuttings under vacuum, but also removing cuttings under reduced pressure or “vacuum” conditions, and utilizing the pumping means to selectively convey the cuttings onwards via dedicated conduits to a cuttings storage container, or directly into a cuttings re-injection facility, offers several significant advantages.
Firstly, the demands on the crane are reduced because the cuttings containers do not need to be continually cycled around for filling and emptying operations. The containers can be stowed or sited in convenient locations without taking account of the shaker station position other than to ensure that suitable vacuum conduit lines are available or provided to feed the cuttings directly into the containers. The crane then becomes essentially free to fulfill other essential tasks such as handling drill pipe etc. The freedom to locate containers anywhere that a cuttings vacuum transport line can be installed and accessed immediately also provides greater freedom on the deck for operator movement, and greater flexibility in utilization of deck space around the shaker station and elsewhere.
Secondly it offers the possibility of directly off-loading cuttings to a barge or bulk transport ship standing on station close to the drilling facility.
Thirdly, health and safety aspects are enhanced due to reduced contact between workers and the cuttings, who need longer clamber over the cuttings containers to access them thereby reducing contamination hazards and risks of personal injury by falls.
The conduit network may be a fixed installation or arranged so as to permit re-deployment of a selected or each conduit at will. The conduits are designed sufficiently to permit transfer of the particulate solids constituting the cuttings and avoid blockages, and pump overloading but are also sized to avoid loss of vacuum transfer velocity.
It will be understood that the pumping means referred to herein in relation to the various aspects of the invention may consist of one or more pumps having the necessary functions of generating a pressure differential to move cuttings in the desired way and combinations of pumps can be adopted.
Preferably, the pumping means comprises, at least, (i) gas pumping means e.g. a vacuum generating unit capable of creating the desired pressure reduction in the vessel and (ii) a solids displacement means, which may be one of several types suitable to the purpose, including positive displacement pumps, e.g. a piston pump, or paddle devices e.g. using rubber paddles, or a progressive cavity pump capable of continuous displacement of solids, preferably at about 25 tons per hour or more. Advantageously, location of the pumping means external to the vessel is such that solids displacement is so primarily lateral rather than vertical as required for the known solids free-fall under gravity system, which reduces height requirements The vessel can then be installed at ground (deck) level with no height elevation requirements which improves safety for operatives.
In this way equipment provided in accordance with the invention can exhibit a relatively low profile compared with prior art systems and is more easily installed and maintained by operatives with less risk of injury due to falls. Furthermore in contrast with the prior art operational system described above where the vertically arranged helical screw is within the cuttings hopper itself, the pressure vessel arrangement described herein is less complicated in structure and provides for easier care and maintenance operations.
Overall, the system proposed herein results in more efficient use of space in the installation, and reduces hazards associated with earlier systems.
The vessel and pumping means described herein are operationally connected so as to maintain a reduced pressure or vacuum within the system, which may be achievable by fastening arrangements satisfying usual industry pressure vessel standards, including flanged connections and dedicated hard conduits of adequate strength. The reduced pressure can be maintained by a suitable type pump known in the industry or custom built for this system.
It will be understood that primarily the invention addresses solids handling, and the precise nature of the vacuum unit or gas pump is not critical. The arrangement of the invention is such that the pumped cuttings can either be directed from the reduced pressure vessel into appropriate storage facilities such as containers or directly into a cuttings re-injection device enabling the cuttings to be returned to the drilled formation. Furthermore the cuttings can be “piped” off the installation into a barge or similar bulk cargo transporter.
Cuttings re-injection under high pressure back into an earth formation is described in principle in the following U.S. Pat. Nos. 4,942,929, 5,129,409, and 5,109,933, and treatment of drill cuttings is discussed in the following U.S. Pat. Nos. 4,595,422, 5,129,468, 5,361,998 and 5,303,786. However, these early proposals have not been easy to implement in the field for those lacking the appropriate skill and understanding, and this has resulted in cuttings re-injection not gaining wide acceptance amongst operators, especially in offshore drilling installations in the North Sea.
The present invention arises from developments following on from proven re-injection techniques successfully employed by APOLLO Inc. in offshore drilling operations.
DESCRIPTION OF THE DRAWINGS
The invention will now be further described with reference to the accompanying drawings in which:
FIG. 1
is a plumbing illustration arrangement for the preferred embodiment of the materials handling system;
FIG. 2
is a plumbing illustration arrangement for an alternate embodiment of the preferred system;
FIG. 3
is a plumbing illustration arrangement for an alternate vacuum system;
FIG. 4
is a plumbing arrangement and an optional discharge receptacle for the system shown in
FIG. 3
system;
FIG. 5
is a plumbing arrangement and an optional discharge receptacle for the system shown in
FIG. 3
system;
FIG. 6
is a cutaway side elevation of a low profile reduced pressure vessel and associated pumping means in accordance with the invention;
FIG. 7
is side elevation of a low profile reduced pressure vessel and associated pumping means in accordance with the invention:
FIG. 8
is a plumbing arrangement for the system shown in
FIG. 2
adding an optional surge tank.
FIG. 9
is a plumbing arrangement for the system shown in
FIG. 1
with addition of an optional surge tank and pump combination;
FIG. 10
is a plumbing arrangement for the system shown in
FIG. 5
with separator discharging into a surge tank.
FIG. 11
is a top view of the surge tank;
FIG. 12
is a cross section view of the surge tank;
FIG. 13
is a plumbing arrangement for the system first shown in shown in
FIG. 8
substituting a centrifugal dryer for the surge tank;
FIG. 14
is a second embodiment of the plumbing arrangement for the system shown in
FIG. 13
;
FIG. 15
is a third embodiment of the plumbing arrangement for the system shown in
FIG. 13
; and
FIG. 16
is a fourth embodiment of the plumbing arrangement for the system shown in FIG.
13
.
DETAILED DESCRIPTION
As shown in
FIG. 1
, the preferred embodiment of the invention is a system by which cuttings leaving the shaker
10
may be collected from the cuttings trough
12
by gravity feed into a progressive cavity or fixed displacement piston type solids pump
14
and then pumped through a system, of conduits selectively to one or more of the possible discharge ports or disposal points located around the drilling site or platform. Such disposal points or discharge ports may be selected by opening valves
16
as needed to dispense the cuttings to a cuttings/fluid separator
18
, a barge
20
a cuttings box
22
or other transport means such as a truck
24
for further disposition.
Defluidized cuttings discharged from the separator
18
may be collected in various containers such as a cuttings box
22
seen in
FIG. 3
, a truck
24
as seen in
FIG. 5
or into a slurry processing unit
26
for injection into the earth formation around the well as also seen in FIG.
1
.
By adding a vacuum pump unit
28
and vacuum chamber
30
as seen in
FIG. 2
to the solids pump
14
and its associated system shown in
FIG. 1
the system is then capable of extracting the cuttings from the cuttings trough by vacuuming them directly into the chamber
30
which serves as a hopper for feeding the cuttings to the solids pump
14
. As discussed herein this arrangement is useful when space under the cutting trough is insufficient to accommodate the solids pump
14
. Since the cuttings are still in slurry they can be pumped to the various discharge points. However, once the fluids have been extracted by the separator
18
it is much more difficult to move the materials without adding more fluid. Therefore, the defluidized cuttings are discharged from the separator
18
directly to the containers
22
,
24
or to the injection processing unit
26
as disclosed in
FIGS. 3-5
.
Turning now to
FIG. 3
we see that the previously known fluid separator
18
may also be used as the vacuum chamber for extracting the cuttings directly from the cuttings trough
12
. However, the separator has the distinct advantage of being capable of efficiently removing and reclaiming most of the remaining fluids from the cuttings thereby reducing the weight and volume of the cuttings to be transported.
As shown in
FIG. 6
, the previously known operational fluid separator system
18
collects cuttings
15
from the cuttings trough
12
that collects solids falling via gravity from inlet suction line
32
as a result of the separator having a reduced internal pressure created by the gas suction pump system
28
seen in
FIG. 2
attached to the separator by line
34
. The separator
18
is generally diametrical in shape having cylindrical side walls
35
and a top
40
with a sloping mid portion
110
and a smaller cylindrical lower portion
52
culminating at an open discharge port
85
. The interior is divided into an upper chamber
38
bound by side wall
35
, top
40
and inclined partition
45
, a mid chamber
105
bound by the inclined partition
45
sloping side wall
110
and partition
56
and a lower chamber
58
within the smaller cylindrical lower portion
52
serving as the housing for an adjustable valve assembly
75
.
The upper chamber communicates with the mid and lower chambers
105
,
58
with screen assembly
50
. Positioned substantially central along the vertical axis of the screen member
55
is a shaft
60
, which supports a screw conveyor driven by a motor drive
90
. The screw flight portion
65
extending from the upper chamber through the screen assembly
50
and culminating at the screen discharge end portion
70
which is substantially blocked by valve assembly
75
.
Cutting being conveyed from the upper chamber
38
to the discharge port
70
must force the valve open to allow the cuttings to
15
to communicates with lower chamber
58
and be discharged through the discharge chute
80
. Chute
80
empties into opening
85
which disposes cuttings into a container as seen in
FIGS. 3-5
.
The side walls
35
, inclined walls
45
, and screen assembly
50
communicate and form a seal with the screw flighting
65
and the mid chamber
105
so that when a vacuum is applied using suction line
34
, cuttings can be suctioned from trough
12
to the upper chamber
38
of the separator and then conveyed through the screen assembly
50
to wards the closed valve assembly
75
thereby compressing the cuttings
15
and forcing fluids and solids less than 20 micron through the screen
55
and apertures in screen sleeve member
100
. Fluids accumulated in the mid chamber
105
are then drawn off by pump
115
to be a fluids recovery container
120
via discharge line
95
. The remaining solids are disposed of via discharge valve assembly
75
and travel down the discharge chute
80
under gravity and are emptied into containers via the opening
85
where they await disposal or re-injection.
The reduced pressure vessel
30
first illustrated in FIG.
2
and further detailed in
FIG. 7
, illustrating this aspect of the invention, there is shown a relatively low profile reduced pressure vessel
205
and associated pumping means
210
in accordance with the present invention. The apparatus
200
for handling of cuttings comprises a vessel
205
adapted to sustain a reduced internal pressure with respect to external ambient atmospheric pressure, and operationally connected thereto, external pumping means
210
capable of both operations of maintaining the reduced internal pressure and removing cuttings from the vessel
205
, and means including a conduit
215
for selectively delivering cuttings to either a storage facility or to a cuttings re-injection apparatus. (not shown)
The illustrated vessel
205
has four generally rectangular sides
225
, which communicate with an opening
230
via inclined walls
255
and a delivery chute
240
. The vessel
205
also has a rectangular top cover
245
. The vessel
205
is supported by a framework
250
to which it is attached, e.g. by welds. However, it will be appreciated that other shapes of sealed pressure vessel can be adapted in the invention. The system described here is designed to fully satisfy current industry pressure vessel standards.
The pumping means
210
illustrated comprises a progressive cavity pump
220
capable of continuous displacement of solids, here at about 25 tons per hour or more. Other positive displacement pumps may also be used, Location of the pumping means
210
external to the vessel
205
is such that solids displacement is primarily lateral rather than vertical as required for the known solids free-fall under gravity system which provides for low height requirements. The vessel
205
is installed at ground level with no height elevation requirements. In this way the equipment has a low profile and is more easily installed and maintained with less risk to maintenance technicians or other operatives of falling.
Furthermore in contrast with the prior art operational system described above where the vertically arranged helical screw is within the vessel itself, the arrangement described herein is less complicated in structure and provides for easier care and maintenance operations.
The vessel
205
and pumping means
210
described herein are operationally connected so as to maintain a reduced pressure be low atmosphere or vacuum within the system, which may be achievable by fastening arrangements satisfying usual pressure vessel standards, including flanged connections
240
and dedicated hard conduits of adequate strength. The reduced pressure can be maintained by a vacuum pump of any suitable type, and although illustrated here as having both gas and solids pumping means together, the gas (vacuum) pump could be remote from the solids pump. The arrangement of the invention is such that the pumped cuttings can either be directed from the reduced pressure vessel
205
into appropriate storage containers or directly back into a cuttings re-injection device as a matter of operator's choice, as is apparent from the flow illustration seen in
FIGS. 1 and 2
.
As seen in
FIG. 8
the cuttings handling system may also be configured to include a surge or holding tank
300
whereby the cuttings slurry being discharged from the pump
14
is received and held for selective redistribution and pumping to the various containers and systems around the drill site. This surge tank
300
may be necessary to insure that the system does not become constipated and back up as result an inability to discharge the cuttings freely to a container.
As seen in
FIG. 9
the surge tank
300
which includes an integral progressive cavity pump
310
may also be used as the prime pump system whereby the cuttings are received directly from the shaker screens
10
or from the shaker trough
12
by gravity feed. The cuttings are then agitated and maintained in solution until pumped down stream to the site containers or other systems.
As seen in
FIG. 10
it is also possible to locate the surge tank
300
in position to receive cuttings directly from the cuttings fluid separator
18
. In this case the cuttings have been striped of their valuable drilling fluids and recovered. Therefore, the cutting may be discharged into the surge tank where water or other environmentally adaptable fluids are added through conduit
312
, which help prepare the cuttings for earth reclamation prior to discharge to the cuttings container and systems.
As seen in
FIGS. 11 and 12
the surge tank
300
includes a rectangular vessel having a bottom
314
and side and end walls
318
,
316
. A progressive cavity or other such large volume positive displacement type pump is integrated into one end wall as best seen in
FIG. 12. A
partition
320
having a central gate portion
322
with removable portions
324
to allow for control of fluid/sediment levels within the vessel. An agitation system
326
is also provided which is trackable on wheels along rails attached to the upper sides of the tank walls
318
. The agitator includes a bridge
328
supported by wheel assemblies. A drive
332
is also provided for moving the bridge
328
from one end of the tank to the other. A pair of telescopic cylinders
334
is provided for extending and retracting a centralizing screw conveyor auger
336
. The auger serves to move the cuttings toward the center of the tank and help maintain them in solution so that they will flow over the partition gate
322
.
In off-shore drilling, it is essential that digestion and disposal of the drill cuttings flowing from the well at inconsistent flow rates be processed and disposed of in a manner that prevents constipation of the drilling operation. Therefore, the more alternatives available for cuttings disposal and fluid recovery on a drilling rig the better. In keeping with this principle alternatively, a centrifugal dryer
400
may be adapted to the systems as previously illustrated in
FIGS. 1 and 2
in the manner illustrated in
FIGS. 13 and 14
. As seen in
FIG. 13
cuttings are transferred to the vacumn receiving tank and pump assembly
30
through suction line
32
from the cuttings trough
12
in the same manne as in FIG.
12
. The cuttings are then transferred from the vacuum chamber
30
with the pump
14
and deposited into the inlet
402
of the centrifugal dryer
400
where the cuttings are spun at high speed forcing the fluids from the slurry out though the fluid ejection tube
404
. The relatively dry cuttings, typically below 3% fluid by weight, are then deposited into a receiving bin
403
capable of storing large quantities of the dried cuttings before being discharged by way of the transfer conveyor
406
. The transfer conveyer may also contain a metering feeder
408
with internal seals to prevent back flow of the dried cuttings, prior to feeding the cuttings into the transfer line
500
. The transfer line
500
may be charged with an additional blower
28
a
such as that used in assembly
28
previously disclosed herein. A venturi located within jet pump
502
may be used to help draw the dry cuttings into the charged discharge line
500
. Dry cuttings are then directed to any of several optional outlets leading to receiving units
20
-
26
by opening and closing valves
16
. Cyclone separators
504
are located at each of the receiving units for separating and exhausting the pressurized air prior to discharge into the receiving units. Exhausted air may be discharged to atmosphere through exhaust/filter units to remove fine cuttings particles.
As seen in
FIG. 13
dried cuttings may be transferred directly from the transfer conveyor
406
to transfer lines leading to the optional outlets
20
-
26
. In this case a second vacuum pump
28
is collectively connected to the discharge of each cyclone separator
504
located at each of the optional distribution outlets
20
-
26
thereby drawing the cuttings through the distribution lines. In this case any airborne fines are collect in the filter receiver
510
located inline ahead of the vacuum pump
512
.
As seen in
FIG. 14
a primary and secondary means of fluid separation and recover may be used whereby the fluid separator unit
18
is utilized as the vacuum chamber for vacuuming the cuttings from the cuttings trough regardless of whether or not the cuttings compression feature of the separator is utilized or not. However, if the cuttings compression and fluidseperation feature is utilized the cuttings will enter the inlet of the centrifical dryer unit
400
with less moisture content, thereby insuring a more through recover of drilling fluids and muds and dryer cuttings being fed to the cuttings transfer system.
It is also anticipated that cuttings may be collected from any number of cuttings troughs
12
and conveyed by a screw conveyer
405
to the inlet of the centrifugal dryer unit
400
as seen in FIG.
16
.
In either case the systems shown in
FIGS. 15 and 16
reduce cuttings bulk and transport weight and further recover expensive drilling fluids.
The cuttings handling systems proposed herein offers remarkably higher levels of safety due to the reduced number of handling operations such as interventions by operatives to hook up containers to the crane, transfers of containers around the shaker station, etc. Furthermore, the sealed vacuum pressure vessel and associated network of vacuum conduits provides for delivery of cuttings to a container, re-injection equipment or transport for shipping to a remote disposal site, thereby preventing the possibility of constipation due to high production of drill cuttings at any given time.
The full significance of the capabilities of the system proposed here, and variants thereof will be apparent to those appropriately skilled in this art and who will recognize that the scope of the invention is not limited to the illustrative embodiment specifically described above.
Claims
- 1. A system for moving heavy drill cuttings from a drill site shaker screen and cuttings trough to various points on and around a drill site comprising:a) a first cuttings transfer means having containment means for receiving said drill cuttings for extracting and receiving drill cuttings entrained in a fluid slurry from said cuttings trough; b) a fluid separator apparatus adapted to said first transfer means for recovering virtually all residual drilling fluids and mud from said cuttings while drying said drill cuttings to a moisture content of between 2 and 5% by weight; c) a collecting bin for holding dried drill cuttings discharged from said fluid separator means; d) a second cuttings transfer means adapted to said collecting bin for discharging said dried drill cuttings in an extruded manner; and e) a conduit network connected to said second transfer means said conduit network comprising a plurality of valves for selectively directing said dried drill cuttings being extruded into said network by said second transfer means to a plurality of disposal discharge ports selectable by operating said valves.
- 2. The system according to claim 1 wherein said first transfer means is a gravity feed chute connected to discharge port of said cuttings trough and inlet to said fluid separator.
- 3. The system according to claim 1 wherein said first transfer means comprises a vacuum means or collecting said drill cuttings from said cuttings trough and discharging said cuttings slurry into said fluid separator means.
- 4. The system according to claim 3 wherein said vacuum means further comprises a means for force feeding said drill cuttings from said vacuum means into said fluid separator.
- 5. The system according to claim 3 wherein said vacuum means further comprises a means for recovering fluids from said slurry for reuse by compression of said drill cuttings.
- 6. The system according to claim 1 wherein said transfer means is a pneumatic system for transferring said drill cuttings, adapted to said collecting bin and said conduit network.
- 7. The system according to claim 1 wherein said fluid separator means is a centrifugal dryer.
- 8. The system according to claim 7 wherein said centrifugal dryer contains a means for recovering fluids from said slurry for reuse as a result of spin drying.
- 9. The system according to claim 8 wherein said centrifugal dryer further comprises a receiving and holding bin attached thereto for collecting dried drill cuttings discharged from said centrifugal dryer.
- 10. The system according to claim 9 wherein said receiving and holding bin further comprises a means for forcibly discharging and metering said dry drill cuttings from said holding bin into said conduit network.
- 11. The system according to claim 10 wherein said conduit net work is positively charged with pressure and further comprises a venture' pump to assist in the discharge of said dry drill cuttings from said holding bin into said conduit network.
- 12. The system according to claim 10 wherein said dry drill cuttings are drawn through said conduit network by vacuum.
- 13. The system according to claim 10 wherein each of said disposal discharge ports is fitted with a cyclone separator operable pneumatically.
- 14. The system according to claim 1 wherein at least one of said disposal discharge ports is connected to a cutting injection system.
- 15. The system according to claim 1 wherein at least one of said disposal discharge ports comprises a cyclone separator.
- 16. A drill cuttings distribution system comprising:a) a solids pump having a receiving vessel attached to an inlet of said solids pump; b) a vacuum pump attached to said receiving vessel; c) a suction line connected to said receiving vessel for remotely collecting and conducting drill cuttings into said vessel; d) a centrifugal dryer with fluid separation means and having means for receiving said drill cuttings from said solids pump; e) a means for recovering fluids separated and discharged from said drill cuttings; f) a means for receiving and storing dry cuttings discharged from said centrifugal dryer; g) a means for discharging said dry cuttings from said means for receiving and storing dry cuttings and g) a means for selectively conducting said dry cuttings pneumatically from said means for discharging dry cuttings, to remote disposal discharge ports.
- 17. The drill cuttings distribution system according to claim 16 wherein said means for selectively conducting is a system of pipes having a plurality of valves therein for routing said dry drill cuttings to various discharge ports.
- 18. The drill cuttings distribution system according to claim 17 wherein said means for discharging said dry cuttings from said means for receiving and storing dry cuttings comprises:a. a conveying means having a discharge port connected to said means for selectively conducting said drill cuttings; b. a cyclone separator having an inlet and outlet said inlet connected to said means for selectively conducting said drill cuttings said cyclone separator located at each of said remote discharge ports said outlet of each said cyclone separator connected to a vacuum pump; and c. a means for collecting and transporting said dry drill cuttings discharged from each said cyclone separator.
- 19. The drill cuttings distribution system according to claim 17 wherein said system further comprises:a) a means for pressurizing said system of pipes; b) a feed means for collecting and metering said drill cuttings discharged from said centrifugal dryer into said pipes said feed means further comprising a venturi locate inline with said pipes; c) a cyclone separator having an inlet and outlet said inlet connected to said means for conducting said drill cuttings said cyclone separator located at each of said remote discharge ports said outlet of each said cyclone separator connected to a vacuum pump; d) an exhaust filter attached to said outlet of each said cyclone separator; and e) a means for collecting and transporting said drill cuttings discharged from each said cyclone separator.
- 20. A method for moving heavy drill cuttings from point to point about a drill site comprising the step of providing a means for collecting and transferring heavy drill cuttings entrained in a fluid slurry, providing preliminary fluid separation and recovery means, providing secondary fluid separation and recovery means and discharging said heavy drill cuttings in a dry form into a conduit transfer system for discharge at various points on and around a drill site.
- 21. The method according to claim 20 further including the step of employing a vacuum system as said means for collecting and transferring said heavy drill cuttings to said secondary drying means.
- 22. The method according to claim 21 wherein said method further comprises the steps of:a) compressing said heavy drill cuttings and recovering fluids from said drill cuttings for reuse; b) centrifugally drying and recovering remaining fluids from said drill cuttings discharged from said preliminary fluid separation and recovery means; and c) discharging defluidized dry cuttings from said secondary drying means through a conduit system selectively into a plurality of transport means.
- 23. The method according to claim 20 wherein said method further includes the steps of:a) providing a separator means for receiving and defluidizing said cuttings; b) defluidizing said cuttings within said separator; c) recovering said fluid for reuse; and d) discharging defluidized cuttings into a re-injection cuttings processing system.
- 24. The method according to claim 23 wherein said separator means for defluidizing said cuttings slurry further comprises the steps of:a) receiving said cuttings slurry containing fluids and solids into an upper chamber by reducing pressure below atmosphere in said chamber; b) conveying said cuttings slurry through a central strainer towards a blocked pressure adjustable discharge port; c) compressing said cuttings slurry within said strainer; d) expressing said fluids and solids less than 20 micron through said strainer; e) collecting and recovering said fluids; f) forcing said blocked discharge port to open against a preset pressure; and g) discharging defluidized cuttings.
- 25. The method according to claim 24 further comprising the step of pumping the recovered fluids and solids under 20 microns from said separator means to a remote location.
US Referenced Citations (3)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2 339 443 |
Jan 2000 |
GB |