High temperature explosives for downhole well applications

Abstract

The present invention provides explosive compositions adapted for use in downhole well applications requiring high temperature explosives that may be exposed to elevated temperatures for extended periods of time.

Description

FIELD OF THE INVENTION

[0001] The subject matter of the present invention relates to downhole explosives. More specifically, the subject matter of the present invention relates to explosives for use in downhole wells for applications requiring performance capability at high temperature and/or exposures at elevated temperatures for extended periods of time.

BACKGROUND OF THE INVENTION

[0002] Explosives are used in numerous downhole well applications. An essential consideration in selecting explosives for use in downhole applications, such as perforating operations, is that the explosives have a certain range of time and temperature in which the explosives are thermally stable. If the explosives are stretched beyond this range, the explosives start to decompose, burn, or auto-detonate. Decomposition of explosives generally reduces their effectiveness and can cause a failure such as a misfire (a failure to detonate).

[0003] Failures of explosives are costly and often dangerous. For example, with regard to perforating applications, when a perforating gun string is lowered to a desired depth but for some reason cannot be activated, a mis-run has occurred. The mis-run requires that the perforating gun string be pulled out of the wellbore and replaced with a new gun string. Such replacement is both time consuming and expensive. Also, retrieving a mis-fired gun from a wellbore can be a hazardous operation.

[0004] Because of the time-temperature range considerations regarding explosives, in the past, use of explosive devices in downhole applications has, in some instances, been precluded. In many operations where explosive actuation was desired (i.e., a device using a frangible member), alternative actuating means were selected because of the risky nature of the explosives within the high temperature environment. In order to use explosive devices in most downhole operations, it is imperative that the operating time for the explosives be increased for a given temperature.

[0005] There is, therefore, a need for explosive compositions adapted for use in downhole well applications requiring explosives that may be exposed to elevated temperatures for extended periods of time. There is a need for such explosives having improved thermal stability for use in perforating applications for shape charges, boosters, detonating cords, and detonators. Additionally, there is a need for such explosives with improved thermal stability for use in tubing and casing cutters, explosive-actuated sleeves, sonic or seismic fracing devices, setting devices, explosive actuated sliding sleeves, valves or shuttles, breakable or frangible elements, tubing release devices, and actuating devices, for example.

SUMMARY OF THE INVENTION

[0006] One embodiment of the present invention provides identified high temperature downhole explosives for use in downhole well devices. Such explosives, exhibit thermal stability characteristics suitable for downhole applications.

[0007] Further scope of applicability of the present invention will become apparent from the detailed description presented hereinafter. It should be understood, however, that the detailed description and the specific examples, while representing a preferred embodiment of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become obvious to one skilled in the art from a reading of the following detailed description.

BRIEF DESCRIPTION OF THE INVENTION

[0008] A full understanding of the present invention will be obtained from the detailed description of the preferred embodiment presented herein below, and the accompanying drawings, which are given by way of illustration only and are not intended to be limitative of the present invention, and wherein:

[0009] FIG. 1 is a diagrammatic sketch of a downhole device that is part of a tool string within a well.

[0010] FIG. 2 is a cross-sectional view of an embodiment of the present invention for use in a typical shaped charge adapted for use in a perforating gun.

[0011] FIG. 3 is a cross-sectional view of another embodiment of the present invention for use in a typical tubing or casing cutter.

[0012] FIGS. 4 a and 4b are cross-sectional views of yet another embodiment of the present invention for use in a typical tubing release mechanism.

[0013] FIG. 5 is a diagrammatic sketch of still another embodiment of the present invention for use in a sonic fracing device.

[0014] FIGS. 6 a and 6b are cross-sectional views of another embodiment of the present invention for use in an explosively set downhole apparatus. FIG. 6a displays the apparatus prior to explosive bonding, and FIG. 6b displays the apparatus after explosive bonding.

[0015] FIGS. 7 a -7c are cross-sectional views of another embodiment of the present invention for use in an apparatus for explosively opening a production valve.

[0016] FIG. 8 is a cross-sectional view of another embodiment of the present invention for use in an apparatus for actuating downhole tools.

DETAILED DESCRIPTION OF THE INVENTION

[0017] In the following detailed description of the subject matter of the present invention, identified high temperature downhole explosives are principally described as being used in oil well applications. Such applications are intended for illustration purposes only and are not intended to limit the scope of the present invention. The identified high temperature downhole explosives can also be used to advantage in operations within gas wells, water wells, injection wells, and control wells. All such applications are intended to fall within the purview of the present invention. However, for purposes of illustration, the identified high temperature downhole explosives will be described as being used for oil well applications.

[0018] As shown in FIG. 1, the identified high temperature downhole explosives are principally described as being used in downhole well devices that are part of a tool string. The identified high temperature downhole explosives of the present invention can be used for any conceivable downhole device/application for which explosives are suitable. More specifically, the identified high temperature downhole explosives are particularly suited for applications requiring high performance capability (i.e., jet production) combined with thermal stability at high temperature and/or exposures at elevated temperatures for extended periods of time. To achieve such performance, the high temperature downhole explosives are characterized by minimal gas loss caused by exposure to elevated temperatures for extended periods of time. The temperature/time suitability or performance ratings of the identified high temperature downhole explosives provide a substantial benefit in the ability of tools and equipment to perform well at elevated temperatures for extended periods of time.

[0019] One such identified high temperature downhole explosive is nonanitroterphenyl (NONA). The temperature/time suitability or performance ratings of explosive components utilizing NONA, for example, exceed 500° F./1 hour, 460° F./100 hours, and 420° F./400 hours. Temperature Vacuum Stability Tests performed on NONA reveal that NONA sustains minimal gas loss at 392° F. even after exposure of approximately 90 days. Thus, NONA exhibits exceptional thermal stability suitable for downhole applications.

[0020] Other identified high temperature downhole explosives exhibiting similar thermal stability qualities include, but are not limited to, octanitroterphenyl (ONT), pentanitrobenzophenone (PENCO), tetranitronaphthalene (TNN), tripicryltriazine (TPT), and tetranitrobenzotriazolo [1,2-a] benzotriazole (T-Tacot).

[0021] Table I to follow provides the results of a Temperature Vacuum Stability Test for the above mentioned identified high temperature downhole explosives. The table demonstrates the temperature/time suitability at a temperature of 200° Celsius (392° Fahrenheit). Each of the above-mentioned identified high temperature downhole explosives exhibit exceptional thermal stability at 200° Celsius. They sustain minimal gas loss while being exposed to the elevated temperature for extended period of time.

TABLE I
200° Temperature Vacuum Stability Tests
	Time or exposure (days)
	2	7	14	21	28	35	42	49	56	63	70	77	84	91
	Total gas evolved (cm3/g at STP)
NONA	.4	.8	1.1	1.6	2.0	2.3	2.8	3.2	3.6	3.9	4.3	4.7	5.1	5.4
ONT	.9	1.3	1.4	1.5	1.6	1.7	1.9	1.9	2.0	2.1	2.3	2.4	2.5	2.6
PENCO	.1	.2	.3	.4	.6	.6	.6	.7	.7	.9	1.0	1.1	1.2	1.4
TNN	.3	.5	.6	.8	.9	1.0	1.2	1.3	1.4	1.6	1.7	1.8	2.0	2.2
TPT	.2	.2	.4	.4	.4	.4	.5	.5	.6	.7	.9	1.0	1.0	1.1
T-tacot	.1	.5	.9	1.3	1.6	1.9	2.1	2.5	3.0	3.5	3.9	4.3	4.8	5.3

[0022] The following identified high temperature downhole explosives exhibit exceptional thermal stability at the elevated temperature of 175° Celsius (347° F.). Such identified high temperature downhole explosives include, but are not limited to, picrylaminotriazole (PATO), dinitropicrylbenzotriazole (BTX), dodecanitroquaterphenyl (DODECA), tripicrylmelamine (TPM), axobishexanitrobiphenyl (ABH), tetranitrobenzotriazolo [2,1-a] benzotriazole (Z-Tacot), potassium salt of hexanitrodiphenylamine (KHND), and tripicrylbenzene (TPB).

[0023] Table II to follow provides the results of a Temperature Vacuum Stability Test for the above mentioned identified high temperature downhole explosives. The table demonstrates the temperature/time suitability at a temperature of 175° Celsius (347° Fahrenheit). Each of the above-mentioned identified high temperature downhole explosives exhibit exceptional thermal stability at 175° Celsius. They sustain minimal gas loss while being exposed to the elevated temperature for extended period of time.

TABLE II
175° Temperature Vacuum Stability Tests
	Time or exposure (days)
	2	7	14	21	28	35	42	49	56	63	70	77	84	91
	Total gas evolved (cm3/g at STP)
PATO	.1	.4	.6	.7	.8	.9	1.1	1.2	1.3	1.4	1.4	1.4	1.4	1.5
BTX	.2	.3	.4	.4	.5	.6	.7	.8	1.0	1.1	1.1	1.2	1.2	1.3
DODECA	.5	.7	.8	.9	.9	.9	1.0	1.0	1.0	1.1	1.2	1.3	1.4	1.4
TPM	1.5	2.0	2.3	2.6	2.9	3.3	3.7	4.1	4.5	4.9	5.2	5.5	5.9	6.7
ABH	.4	.7	1.0	1.3	1.6	2.0	2.4	2.7	3.0	3.4	3.7	4.0	4.3	4.7
Z-Tacot	.4	.5	.6	.7	.7	.7	.7	.7	.8	.9	1.0	1.1	1.4	1.7
KHND	.1	.4	.5	.7	.8	1.0	1.1	1.3	1.4	1.6	1.8	2.0	2.2	2.4
TPB	.1	.1	.1	.1	.1	.1	.2	.2	.2	.2	.2	.2	.3	.3

[0024] The following identified high temperature downhole explosives exhibit exceptional thermal stability at the elevated temperature of 150° Celsius (302° F.). Such identified high temperature downhole explosives include, but are not limited to, dipicramide (DIPAM), hexanitroazobenzene (HNAB), bis-hexanitroazobenzene (bis-HNAB), hexanitrobiphenyl (HNBP), dipicrylbenzobiatriazoledione (DPBT), dipicrylpyromellitude (DPPM), hexanitrodiphenylsulfone (HNDS), and bis [picrylazo] dinitropyridine (PADP-I).

[0025] Table III to follow provides the results of a Temperature Vacuum Stability Test for the above mentioned identified high temperature downhole explosives. The table demonstrates the temperature/time suitability at a temperature of 150° Celsius (302° Fahrenheit). Each of the above-mentioned identified high temperature downhole explosives exhibit exceptional thermal stability at 150° Celsius. They sustain minimal gas loss while being exposed to the elevated temperature for extended period of time.

TABLE III
150° Temperature Vacuum Stability Tests
	Time or exposure (days)
	2	7	14	21	28	35	42	49	56	63	70	77	84	91
	Total gas evolved (cm3/g at STP)
DIPAM	.2	.4	.5	.5	.6	.7	.7	.8	.8	.9	.9	1.0	1.0	1.0
HNAB	.1	.2	.2	.3	.3	.4	.4	.5	.5	.6	.6	.7	.7	.7
bis-HNAB	.5	1.2	1.8	2.5	2.9	3.6	4.2	4.8	5.3	6.0	6.7	7.4	8.1	8.8
HNBP	.2	.3	.3	.4	.4	.5	.5	.5	.6	.6	.7	.7	.8	.8
DPBT	.4	.7	.9	1.0	1.3	1.5	1.7	1.9	2.1	2.2	2.3	2.4	2.5	2.7
DPPM	.3	.7	1.0	1.2	1.4	1.5	1.5	1.6	1.7	1.8	1.9	2.0	2.1	2.2
HNDS	.1	.2	.2	.3	.3	.3	.4	.5	.5	.6	.7	.9	1.1	1.3
PADP-I	5.3	4.9	4.3	4.1	3.9	4.1	4.2	4.2	4.3	4.4	4.5	4.7	4.9	5.0

[0026] Other identified high temperature downhole explosives suitable for downhole use include, but are not limited to, sodium tetranitrocarbozole (NaTNC), hexanitrobibenzyl (HNBIB), tetranitro carbazole (TNC), 3,6 diamino 1,2,4,5 tetrazene (DAT), 2,6-diamino-3,5-dinitropyridino-1-oxide (DADNPO), octanitromacro cycle (ONM), 4,6 dinitrobenzofuroxan (ADNBF), 2,5-dipcryl-1,3,4-oxadiazole (DPO) and m-picrylpicramide (PIPA).

[0027] It is important to note that although several of the above identified high temperature downhole explosives have been grouped according to their thermal stability at particular temperatures, such grouping is only for the purpose of discussion and not intended to define the grouped explosives as equivalent to each other. Although the explosives within the groupings share similar thermal characteristics, that does not translate into equivalent suitability for various applications. Other material properties used in determining suitability for particular applications include impact sensitivity, density, cost, etc. Such other properties are not dependent upon the thermal characteristics of a particular explosive.

[0028] The following examples are illustrative of the numerous downhole applications for which the identified high temperature downhole explosives of the present invention are suitable. Such examples are intended for illustration purposes only and are not intended to limit the scope of the present invention. The identified high temperature downhole explosives can be used to advantage in any downhole application utilizing explosives. All such applications are intended to fall within the purview of the present invention.

[0029] Referring to FIG. 2, a typical shaped charge adapted for use in a perforating gun is illustrated. The perforating gun is adapted to be disposed in a wellbore. Some shaped charges are discussed in U.S. Pat. No. 4,724,767 to Aseltine issued Feb. 16, 1988; U.S. Pat. No. 5,413,048 to Werner et al. issued May 9, 1995; and again in U.S. Pat. No. 5,597,974 to Voreck, Jr. et al. issued Jan. 28, 1997. Each of the above mentioned disclosures are incorporated by reference into this specification.

[0030] In FIG. 2, the shaped charge includes a case 10, a main body of explosive material 12, which in the past has been, for example, RDX, HMX, PYX, or HNS packed against the inner wall of the case 10, a primer 13 disposed adjacent the main body of explosive 12 that is adapted to detonate the main body of explosive 12 when the primer 13 is detonated, and a liner 14 lining the primer 13 and the main body of explosive material 12. The shaped charge also includes an apex 18 and a skirt 16. A detonating cord 20 contacts the case 10 of the shaped charge at a point near the apex 18 of the liner 14 of the charge. When a detonation wave propagates within the detonating cord 20, the detonation wave will detonate the primer 13. When the primer 13 is detonated, the detonation of the primer 13 will further detonate the main body of explosive 12 of the charge. In response to the detonation of the main body of explosive 12, the liner 14 will form a jet 22 that will propagate along a longitudinal axis of the shaped charge. The jet 22 will perforate a formation penetrated by the wellbore.

[0031] In accordance with the present invention, it has been discovered that, when the main body of explosive 12 is comprised of one or more identified high temperature downhole explosives (NONA, PATO, BTX, DIPAM, PENCO, TNN, HNAB, TPM, ABH, bis-HNAB, DODECA, HNBP, Z-Tacot, T-Tacot, DPBT, DPPM, HNDS, KHND, ONT, TPB, TPT, PADP-I, NaTNC, HNBIB, TNC, DAT, DADNPO, ONM, ADNBF, DPO, or PIPA), is comprised of a mixture of one or more identified high temperature downhole explosives and one or more other explosive compounds, such as HNS, PYX, HMX, or is comprised of one or more identified high temperature downhole explosives combined/mixed with one or more of an energetic material and a fuel, and when the primer 13 is carefully selected to be comprised of a sensitive explosive material, the shaped charge exhibits exceptional thermal stability characteristics.

[0032] In the past, the primer 13 had to be comprised of a special explosive material, other than the explosive material comprising the main body of explosive 12, because the explosive material comprising the main body of explosive 12, by itself, was generally not sensitive enough to be included as part of the primer 13. Therefore, the primer 13 was comprised of a special (highly sensitive) explosive material other than the explosive material comprising the main body of explosive 12 in order for the primer 13 to be detonated. However, in the present invention, identified high temperature downhole explosives such as DPO have been found to exhibit sensitivity characteristics suitable for use as the primer 13. Table IV displays the results of an exploding foil initiation (EFI) test in which DPO was compared with compounds having similar explosive properties.

TABLE IV
		Impact
	Thermal Stability at 260° C.	Sensitivity
Explosive	Cc/g/hr. (2 hr.)	(cm)
DPO	0.6	20
NONA	0.5	39
HNS	0.5	45
2,5-dipicryl-3,4-dinitrofuran	0.8 at 230° C.	23

[0033] As is shown by the data of Table IV, the explosives having similar thermal stability characteristics as DPO (HNS and NONA), are not as impact sensitive. Likewise, although 2,5-dipicryl-3,4-dinitrofuran has a similar sensitivity as DPO, it is not as thermally stable. Thus, DPO has a suitable combination of thermal stability and sensitivity to be useful not only as a main body of explosive 12, but also as a primer 13 or booster. One skilled in the art will recognize that those explosives suitable as both the main body of explosive 12 and as the primer 13 enable shape charges to be comprised of a single type of explosive.

[0034] It should be noted, the impact sensitivity of high temperature downhole explosives is often a function of their particle size. As an example, by reducing the particle size of a NONA sample, the impact sensitivity of NONA has been found to be as low as 18 cm. As a consequence, one skilled in the art will recognize that NONA of appropriate particle size exhibits thermal sensitivity characteristics suitable for use as a primer 13 or a booster.

[0035] FIG. 3 illustrates a typical shaped charge adapted for use in a tubing or casing cutter. The tubing or casing cutter is adapted to be disposed in a wellbore for cutting or severing oil well tubing, drill strings, casings, and the like. Typical tubing or casing cutters are discussed in U.S. Pat. No. 3,057,295 to Christopher issued Oct. 9, 1962, U.S. Pat. No. 4,184,430 to Mock issued Jan. 22, 1980, and U.S. Pat. No. 6,053,247 to Wesson et al. issued Apr. 25, 2000. Each of the above mentioned disclosures are incorporated by reference into this specification.

[0036] The shaped explosive charge 30 is mounted within the chamber 32 of the cutter head of the tubing or casing cutter. The shaped charge includes a booster charge element 34 ignited by a detonating fuse 36. The ignited booster charge element 34, in turn, detonates the main explosive charge elements 38 and 40, which produce a radial jet. The radial jet propagates outwardly to cut the surrounding tubing or casing.

[0037] In accordance with the present invention, it has been discovered that, when the main explosive charge elements 38 and 40 are comprised of one or more identified high temperature downhole explosives, are comprised of a mixture of one or more identified high temperature downhole explosives and one or more other explosive compounds, such as HNS, PYX, HMX, or are comprised of one or more identified high temperature downhole explosives and one or more of an energetic material and a fuel or an oxidizer, and when the booster charge element 34 is carefully selected to be comprised of a sensitive explosive material, the shaped charge exhibits exceptional thermal stability characteristics.

[0038] As discussed above with regard to the shaped charges used in perforating guns described with reference to FIG. 2, generally the booster charge element 34 is comprised of a special (highly sensitive) explosive material other than the identified high temperature downhole explosives used for the main explosive charge elements 38 and 40. However, identified high temperature downhole explosives such as DPO can be used to advantage as the booster charge element 34.

[0039] Similar to the tubing or casing cutters, FIGS. 4a and 4b illustrate a typical tubing release mechanism. The tubing release mechanism is adapted to be disposed in a wellbore, and more particularly, connected between a perforating apparatus and a tubing for shattering a frangible breakup tube thereby automatically releasing the perforating apparatus from the tubing in response to a detonation wave passing. A typical tubing release mechanism is discussed in U.S. Pat. No. 5,293,940 to Hromas et al. issued Mar. 15, 1994, the details of which are incorporated by reference into this specification.

[0040] As shown in FIGS. 4a and 4b, when the firing heads 50a and 50b are initiated, a detonation wave is initiated within the detonating cord 52. The detonation wave 52 propagates through the firing head adapter 54, transfer housing 56, release piston 58, frangible breakup tube 60, release mandrel 62, and bottom sub 64, shooting the perforating gun. When the detonation wave propagating in the detonation cord 52 passes through the frangible breakup tube 60, the resultant shock wave and pressure from the detonation wave shatters the frangible breakup tube 60. The breakup tube 60 shatters into small pieces. As a result, the release piston 58 is no longer supported and held in position by the breakup tube 60. The pressure force pushing down on the release piston 58 forces the release piston 58 down into the air chamber 46, which subsequently causes the release of the perforating gun.

[0041] In accordance with the present invention, it has been discovered that, when the detonation cord is comprised of one or more identified high temperature downhole explosives, is comprised of a mixture of one or more identified high temperature downhole explosives and one or more other explosive compounds, such as UNS, PYX, HMX, or is comprised of one or more identified high temperature downhole explosives and one or more of an energetic material and a fuel or an oxidizer, the detonating cord 52 exhibits exceptional thermal stability characteristics.

[0042] FIG. 5 illustrates a sonic fracing mechanism. The tubing release mechanism is adapted to be disposed in a wellbore, and more particularly, to increase formation permeability by creating sonic waves that crack loosen the formation interstices. A typical sonic fracing mechanism is discussed in U.S. Pat. No. 5,293,940 to Beard issued Aug. 27, 1985, the details of which are incorporated by reference into this specification.

[0043] As shown in FIG. 5, the sonic fracing mechanism has a series of cylinders 70 mounted in a tubular housing 72. An explosive is contained in a combustion chamber 74 within each cylinder. The first cylinder is fired, causing an explosion, the shock of which is transmitted through the ambient fluid into the formation. After a preselected interval, another cylinder is fired, with slightly greater shock, and the third firing to follow being greater than the second. The force of the respective explosions creates a wave in the formation, which moves outwardly away from the casing until the force of the explosion is exhausted; then the wave returns through the formation to the casing, where it will be met by the next, and greater explosion, creating a greater wave, thus effecting the washing action clearing passageways for the flow of production fluid.

[0044] In accordance with the present invention, it has been discovered that, when the explosive contained within the combustion chamber is comprised of one or more identified high temperature downhole explosives, is comprised of a mixture of one or more identified high temperature downhole explosives and one or more other explosive compounds, such as HNS, PYX, HMX, or is comprised of one or more identified high temperature downhole explosives combined/mixed with one or more of an energetic material and a fuel or an oxidizer, the combustion chamber exhibits exceptional thermal stability characteristics.

[0045] FIGS. 6 a and 6b illustrate an explosively set downhole apparatus. Setting apparatus are used for the placement or setting of borehole apparatus such as packers, casing bore receptacles, bridge plugs, casing patches, and liner hangers within the casing of a well bore through the explosive bonding of such apparatus to the interior of the casing. Typical explosively set downhole apparatus are discussed in U.S. Pat. No. 4,662,450 to Haugen issued May 5, 1987, and U.S. Pat. No. 5,447,202 to Littleford, the details of which are incorporated by reference into this specification.

[0046] Referring to FIG. 6a, detonation of the explosive charge 80 creates a radial shock wave that drives fixation element 82 radially outward into the casing 84, as shown in FIG. 6b . The fixation element 82 is explosively welded thereto or bonded therewith the casing 84.

[0047] In accordance with the present invention, it has been discovered that, when the explosive charge 80 is comprised of one or more identified high temperature downhole explosives, is comprised of a mixture of one or more identified high temperature downhole explosives and one or more other explosive compounds, such as HNS, PYX, HMX, or is comprised of one or more identified high temperature downhole explosives combined/mixed with one or more of an energetic material and a fuel or an oxidizer, the explosive charge 80 exhibits exceptional thermal stability characteristics.

[0048] FIGS. 7 a -7c illustrate an apparatus for explosively opening a production valve. More particularly, the figures illustrate an apparatus adapted to be disposed in a wellbore having a frangible breakup element that is adapted to shatter into a multitude of pieces when a detonation wave passes therethrough. A piston is supported by the frangible breakup element such that when the frangible breakup element shatters, the piston moves a predetermined distance, thus opening the production valve. An example of an apparatus for explosively opening a production valve is discussed in U.S. Pat. No. 5,318,126 to Edwards et al. issued Jun. 7, 1994, the details of which are incorporated by reference into this specification.

[0049] Referring to FIGS. 7a-7c, a detonation cord 90 is disposed within a series of frangible breakup elements 92 such that a detonation wave propagated by the detonation cord 90 acts to shatter the breakup elements 92. Shattering of the elements 92 removes the support for the piston 94 which is then free to move downwardly in response to either tubing pressure or rathole pressure or both. Once the piston 94 moves downward a predetermined distance, the piston acts to open the production valve.

[0050] In accordance with the present invention, it has been discovered that, when the detonating cord 90 is comprised of one or more identified high temperature downhole explosives, a mixture of one or more identified high temperature downhole explosives with one or more other explosive compounds, such as HNS, PYX, HMX, or one or more identified high temperature downhole explosives combined/mixed with one or more of an energetic material and a fuel or an oxidizer, the detonating cord 90 exhibits exceptional thermal stability characteristics.

[0051] FIG. 8 illustrates an apparatus for actuating downhole tools by firing an explosive charge to generate an operating pressure. An example of an apparatus for explosively actuating downhole tools is discussed in U.S. Pat. No. 5,316,087 to Manke et al. issued May 31, 1994, the details of which are incorporated by reference into this specification.

[0052] As further described below, the power piston 106 reciprocates up and down imparting linear movement of the power mandrel 108 to operate the operating element 110. The operating element 110 may be of many different varieties corresponding to the various tools within the testing string. For example, the operating element 110 may be a rotating ball valve type element of a formation tester valve having an operating mechanism substantially like that shown in U.S. Pat. No. 3,856,085 to Holden et al., the details of which are incorporated herein by reference.

[0053] As another example, the operating element 110 could be a sliding sleeve valve of a reclosable reverse circulation valve having an associated operating mechanism substantially like that shown in U.S. Pat. No. 4,113,012 to Evens et al., the details of which are incorporated herein by reference.

[0054] The operating element 110 may also be a closing element of any one of several types of known sampling apparatus. Also, a multi-mode operating element could be used substantially like that shown in U.S. Pat. No. 4,711,305 to Ringgenberg, the details of which are incorporated herein by reference.

[0055] Referring to FIG. 8, a plurality of explosive charges are contained within the housing 102 and communicated with the upper and lower power chamber portions 114 and 116. The explosive charges (118A, 118B, 118C, and 118D) are electrically fired explosive charges. When any one of the explosive charges 118 is fired, it generates high temperature, high pressure gases within its associated power chamber portion 114, 116 which acts to move the power piston 106 within the power chamber 112.

[0056] In accordance with the present invention, it has been discovered that, when the explosive charges 118 are comprised of one or more identified high temperature downhole explosives, are comprised of a mixture of one or more identified high temperature downhole explosives and one or more other explosive compounds, such as HNS, PYX, HMX, or are comprised of one or more identified high temperature downhole explosives combined/mixed with one or more of an energetic material and a fuel or an oxidizer, the explosive charges 118 exhibit exceptional thermal stability characteristics.

[0057] As discussed above, and as one skilled in the art will recognize, the identified high temperature downhole explosives that comprise the subject matter of the present invention can be used in a great number of downhole applications. In perforating operations, the identified high temperature downhole explosives can be used not only as the main body of explosive of the shape charge, but can also be used for boosters, detonating cords, and detonators, for example. Additionally, the identified high temperature downhole explosives of the present invention can also be used to advantage in applications involving tubing and casing cutters, explosive-actuated sleeves, valves or shuttles, breakable or frangible elements, or sonic or seismic source devices, for example.

[0058] It should be noted that the above discussed application of use for the identified high temperature downhole explosives of the present invention are intended for illustration purposes only, and are not intended as limitations to the scope of the present invention. One skilled in the art will recognize that the identified high temperature downhole explosives are not limited in application. The identified high temperature downhole explosives are useful in any number of downhole wells and any number of applications requiring performance capability at high temperatures and/or exposures at elevated temperatures for extended periods of time.

[0059] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following non-limiting claims.

Claims

1. Explosives for use in downhole well devices, comprising one or more identified high temperature downhole explosives.

2. The explosives of claim 1, wherein the one or more identified high temperature downhole explosives comprise NONA.

3. The explosives of claim 1, wherein the one or more identified high temperature downhole explosives are selected from NONA, PENCO, TNN, T-Tacot, ONT, and TPT.

4. The explosives of claim 1, wherein the one or more identified high temperature downhole explosives are selected from PATO, BTX, TPM, ABH, DODECA, Z-Tacot, KHND, and TPB.

5. The explosives of claim 1, wherein the one or more identified high temperature downhole explosives are selected from DIPAM, HNAB, bis-HNAB, HNBP, DPBT, DPPM, HNDS, and PADP-I.

6. The explosives of claim 1, wherein the one or more identified high temperature downhole explosives are selected from NaTNC, HNBIB, TNC, DAT, DADNPO, ONM, ADNBF, DPO, and PIPA.

7. The explosives of claim 1, further comprising one or more other explosive compounds.

8. The explosives of claim 7, wherein the one or more other explosive compounds are selected from HNS, PYX, and HMX.

9. The explosives of claim 1, further comprising one or more of an energetic material and a fuel.

10. The explosives of claim 1, further comprising one or more of an energetic material and an oxidizer.

11. The explosives of claim 1, wherein the downhole well devices are selected from perforating guns, perforating devices, tubing or casing cutters, tubing release mechanisms, fracing mechanisms, setting apparatus, explosively opening production valves, and downhole tool actuators.

12. The explosives of claim 1, wherein the downhole well devices are part of a tool string.

13. The explosives of claim 1, wherein the downhole well devices are shaped charges.

14. The explosives of claim 1, wherein the one or more high temperature downhole explosives are used in the downhole well devices for explosive components selected from shaped charges, detonators, detonating cords, boosters, and primers.

15. A downhole device having an explosive component, comprising: one or more identified high temperature downhole explosives.

16. The downhole device of claim 15, wherein the one or more identified high temperature downhole explosives comprise NONA.

17. The downhole device of claim 15, wherein the one or more identified high temperature downhole explosives are selected from NONA, PENCO, TNN, T-Tacot, ONT, and TPT.

18. The downhole device of claim 15, wherein the one or more identified high temperature downhole explosives are selected from PATO, BTX, TPM, ABH, DODECA, Z-Tacot, KHND, and TPB.

19. The downhole device of claim 15, wherein the one or more identified high temperature downhole explosives are selected from DIPAM, HNAB, bis-HNAB, HNBP, DPBT, DPPM, HNDS, and PADP-I.

20. The downhole device of claim 15, wherein the one or more identified high temperature downhole explosives are selected from NaTNC, HNBIB, TNC, DAT, DADNPO, ONM, ADNBF, DPO, and PIPA.

21. The downhole device of claim 15, wherein the explosive component further comprises one or more other explosive compounds.

22. The downhole device of claim 21, wherein the one or more other explosive compounds are selected from HNS, PYX, and HMx.

23. The downhole device of claim 15, wherein the explosive component further comprises one or more of an energetic material and a fuel.

24. The downhole device of claim 15, wherein the explosive component further comprises one or more of an energetic material and an oxidizer.

25. The downhole device of claim 15, wherein the device is selected from perforating guns, perforating devices, tubing or casing cutters, tubing release mechanisms, fracing mechanisms, setting apparatus, explosively opening production valves, and downhole tool actuators.

26. The downhole device of claim 15, wherein the device is part of a tool string.

27. The downhole device of claim 15, wherein the explosive component is selected from shaped charges, detonators, detonating cords, boosters, and primers.

28. A shaped charge made by a process, comprising: (a) inserting a main body of explosive into a case, the main body of explosive comprising one or more identified high temperature downhole explosives; and (b) inserting a liner over the main body of explosive.

29. The shaped charge made by the process of claim 28, wherein the one or more defined high temperature downhole explosives comprise NONA.

30. The shaped charge made by the process of claim 28, wherein the one or more identified high temperature downhole explosives are selected from NONA, PENCO, TNN, T-Tacot, ONT, and TPT.

31. The shaped charge made by the process of claim 28, wherein the one or more identified high temperature downhole explosives are selected from PATO, BTX, TPM, ABH, DODECA, Z-Tacot, KHND, and TPB.

32. The shaped charge made by the process of claim 28, wherein the one or more identified high temperature downhole explosives are selected from DIPAM, HNAB, bis-HNAB, HNBP, DPBT, DPPM, HNDS, and PADP-I.

33. The shaped charge made by the process of claim 28, wherein the one or more identified high temperature downhole explosives are selected from NaTNC, HNBIB, TNC, DAT, DADNPO, ONM, ADNBF, DPO, and PIPA.

34. The shaped charge made by the process of claim 28, wherein the main body of explosives further comprises one or more other explosive compounds.

35. The shaped charge of claim 34, wherein the one or more other explosive compounds are selected from HNS, PYX, and HMX.

36. The shaped charge made by the process of claim 28, wherein the main body of explosives further comprises one or more of an energetic material and a fuel.

37. The shaped charge made by the process of claim 28, further comprising a primer inserted into the case adapted for detonating the main body of explosive.

38. The shaped charge of claim 37, wherein the primer comprises NONA.

39. The shaped charge of claim 37, wherein the primer comprises one or more identified high temperature downhole explosives.

40. The shaped charge of claim 37, wherein the primer is an explosive compound more sensitive than the one or more identified high temperature downhole explosives.

41. A method of using one or more high temperature downhole explosives in a well, the method comprising: (a) providing a downhole device having one or more identified high temperature downhole explosives. (b) conveying the downhole device into the well.

42. The method of claim 41, wherein the identified high temperature downhole explosives comprise NONA.

43. The method of claim 41, wherein the one or more identified high temperature downhole explosives are selected from NONA, PENCO, TNN, T-Tacot, ONT, and TPT.

44. The method of claim 41, wherein the one or more identified high temperature downhole explosives are selected from PATO, BTX, TPM, ABH, DODECA, Z-Tacot, KHND, and TPB.

45. The method of claim 41, wherein the one or more identified high temperature downhole explosives are selected from DIPAM, HNAB, bis-HNAB, HNBP, DPBT, DPPM, HNDS, and PADP-I.

46. The method of claim 41, wherein the one or more identified high temperature downhole explosives are selected from NaTNC, HNBIB, TNC, DAT, DADNPO, ONM, ADNBF, DPO, and PIPA.

47. The method of claim 41, further comprising the step of combining the one or more identified high temperature downhole explosives with matter selected from one or more other explosives and one or more of an energetic material and a fuel.