Patent Application
20210332677
The present disclosure relates to systems and methods for oilfield perforating, and more particularly, to perforating downhole tubulars, for example, a casing string, using an explosive component comprising 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,9.03,11]-dodecane (hereafter “TEX”).
After drilling of a wellbore traversing a formation, a casing string may be positioned and cemented within the wellbore. This casing string may increase the integrity of the wellbore and may provide a path for producing fluids from the producing intervals to the surface. To allow fluid flow into the casing string, perforations may be made through the casing string, the cement, and a short distance into the formation.
These perforations may be created by detonating a series of shaped charges disposed within the casing string and adjacent to the formation. Specifically, one or more perforating guns may be loaded with shaped charges that may be connected with a detonator via a detonating cord. The perforating guns may then be attached to a tool string that may be lowered into the cased wellbore. Once the perforating guns are properly positioned in the wellbore such that the shaped charges are adjacent to the target formation, the shaped charges may be detonated, creating the desired perforations.
High-temperature oil and gas wells require perforating explosives with higher thermal stability so as to not prematurely detonate. Moreover, conventional explosive components used for oilfield perforating under certain conditions, such as during unanticipated accident scenarios, may react and cause unintended outcomes to oil and gas workers and even the general public. In order to address this issue, oilfield perforating operations may use explosives having higher thermal stability and reduced sensitivity to impact and friction; however, a drawback to these explosives is that they output less energy and thus sacrifice perforation performance.
Failure to successfully perforate a casing string may result in a loss of productive time and increased operational expenditures.
Illustrative examples of the present disclosure are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein, and wherein:
The illustrated figures are only exemplary and are not intended to assert or imply any limitation with regard to the environment, architecture, design, or process in which different examples may be implemented.
The present disclosure relates to systems and methods for oilfield perforating, and more particularly, to perforating downhole tubulars, for example, a casing string, using an explosive component comprising TEX.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the present specification and associated claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the examples of the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claim, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. It should be noted that when “about” is at the beginning of a numerical list, “about” modifies each number of the numerical list. Further, in some numerical listings of ranges some lower limits listed may be greater than some upper limits listed. One skilled in the art will recognize that the selected subset will require the selection of an upper limit in excess of the selected lower limit.
Examples of the methods and systems described herein relate to perforating downhole tubulars, for example, a casing string, using an explosive component comprising TEX Perforating systems and methods that use TEX as an explosive component may enhance safety significantly in all aspects of the lifecycle of perforating activities, such as, for example, loading at the shop; transportation by highway, air, or water; wellsite handling; retrieval after misruns; and downloading. Moreover, perforating systems and methods that use TEX may achieve increased energy output in perforating operations relative to other explosives having higher thermal stability such as 1,3,5-trinitro-2-[2-(2,4,6-trinitrophenyl)ethenyl]benzene (hereafter “HNS”), thereby providing both increased thermal stability and high energy output (performance potential). Advantageously, the use of TEX also achieves favorable wellbore pressure dynamics (promoting formation cleanup and well productivity) in low pressure environments as TEX yields a reduced quantity of detonation product gasses, thus lowering post-perforating ingun pressure, which in turn expands the operational pressure window, thus creating the favorable wellbore pressure dynamics promoting perforation cleanup. Finally, TEX exhibits reduced sensitivity to impact and friction compared to standard oilfield explosives such as HMX and RDX.
TEX has the chemical formula C6H6N4O8 and the IUPAC name 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,9.03,11]-decane. Any of a variety of suitable techniques may be used for synthesis of TEX. Without limitation, TEX may be synthesized in a “one-pot” synthesis from 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine (hereafter “DFTHP”) and mixed acid (H2SO4/HNO3). The DFTHP thereby partly undergoes proton-catalyzed hydrolysis and yields glyoxal which reacts as with an intermediate to give TEX. Table 1 illustrates the following properties of TEX:
Tables 2-4 compare a variety of properties of TEX with other explosives to illustrate the unique properties TEX possesses.
As shown in the above Tables, TEX may have better attributes with respect to impact and friction, thermal stability, and energy output relative to other explosives. As TEX has a very high thermal stability, with a decomposition temperature potentially reaching 308° C. TEX may be used in wells having wellbore temperatures which exceed the temperature rating of HMX (i.e., 204° C. for 1 hr., 177° C. for 10 hr., 150° C. for 100 hr.) having a decomposition temperature of 280° C. Moreover, TEX still provides sufficient energy output for successful perforating that other high-temperature explosives such as HNS do not.
The TEX may be provided as solid particulates having in any desired particle size. The provided TEX may comprise a variety of particle sizes as desired for a particular application. Without limitation, TEX may have a particle size from about 0.01 micron to about 500 microns, for example, from about 0.01 microns to about 1 microns, from about 1 micron to about 20 microns, from about 20 microns to about 40 microns, from about 40 microns to about 50 microns, from about 50 microns to about 100 microns, from about 100 microns to about 200 microns, or from about 250 microns to about 300 microns. One of ordinary skill in the art should be able to select an appropriate particle size for the TEX for a particular application. In some alternative examples, the TEX may comprise an extrudable or moldable compound instead of or in addition to the solid particulates.
Wellbore 32 may extend through the various earth strata, including subterranean formation 14. While downhole perforating system 10 is disposed in a horizontal section of wellbore 32, wellbore 32 may include horizontal, vertical, slanted, curved, and other types of wellbore geometries and orientations, as will be appreciated by those of ordinary skill in the art. A casing 34 may be cemented within wellbore 32 by cement 36. When it is desired to perforate subterranean formation 14, the downhole perforating system 10 may be lowered through casing 34 until the downhole perforating system 10 is properly positioned relative to subterranean formation 14. The downhole perforating system 10 may be attached to and lowered via work string 30, which may include a tubing string, wireline, slick line, coil tubing or other conveyance. Thereafter, shaped charges 50 within downhole perforating system 10 may be sequentially fired. As will be discussed in more detail below, an explosive component contained in the downhole perforating system 10 may comprise TEX. Upon detonation, shaped charges 50 may form jets that may create a spaced series of perforations extending outwardly through casing 34, cement 36, and into subterranean formation 14, thereby allowing formation communication between subterranean formation 14 and wellbore 32. Shaped charges 50 may be any shape having any desired geometry as would be readily apparent to one of ordinary skill in the art. Examples of potential shapes for shaped charges 50 may include, but are not limited to, conical, linear, circular, square, triangular, rectangular, etc. The shaped charges 50 may be shaped as desired for a particular wellbore operation, for example, downhole perforating, jet cutting, severing, explosive-actuation of downhole tools, explosive-release of downhole tools, etc.
In some examples, at least one of the detonating cord 54, detonating cord initiator 52, donor booster 56, and/or the acceptor booster 70 may comprise the explosive component TEX. In one specific example, all of the detonating cord 54, detonating cord initiator 52, donor booster 56, and the acceptor booster 70 comprise the explosive component TEX. In some examples, TEX may be the sole explosive component of the downhole perforating system 10.
In some alternative examples, the TEX may be mixed with an additional high-temperature explosive such as HNS, 2,2′,2″,4,4′,4″,6,6′,6″-nonanitro-m-terphenyl (hereafter “NONA”), 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (hereafter “HMX”), 2,2-bis[(nitrooxy)methyl]propane-1,3-diyl dinitrate (hereafter “PETN”), 1,3,5-trinitro-1,3,5-triazinane (hereafter “RDX”), 1,3,5-triamino-2,4,6-trinitrobenzene (hereafter “TATB”), 3,3′-diamino-4,4′-azoxyfurazan (hereafter “DAAF”), 2,6-bis(picrylamino)-3,5-dinitropyridine (hereafter “PYX”), 5-nitro-1,2-dihydro-1,2,4-triazol-3-one (hereafter “NTO”), 2,4,6 trinitro-1,3 benzenediamine (hereafter “DATB”), hexanitroazobenzene (hereafter “HNAB”), titanium sub-hydride potassium perchlorate (hereafter “THKP”), 1,3,5-trinitro-2,4,6-tripicrylbenzene (hereafter “BRX”), etc. in order to increase sensitivity, for example, to increase sensitivity of the booster load. The TEX may be provided as a particulate. The particulate TEX may be coated or uncoated. In examples where the TEX particulates are coated, the coating may include, but is not limited to, wax, polyethylene, or a high-temperature binder such as polychlorotrifluoroethylene.
The donor booster 56 may be capable of transmitting a detonation across a discontinuity such as an air gap 72. It does this by its own detonation, in response to a detonation of an adjacent secondary high explosive mass (e.g., detonating cord 54), the donor booster 56 detonation yielding a sufficiently high output to enable transmission across the air gap 72 or the like. Because of the output requirements, a donor booster 56 may comprise a secondary high explosive. Such secondary boosters may not continue/allow a detonation over any discontinuity, for example, an air gap 72. This may mean that the donor booster 56 and the detonating cord 54 to which it is coupled may be in direct physical contact.
An acceptor booster 70, on the other hand, may be one which may detonate in response to another detonation, i.e. in response to the detonation of a donor booster 56 which may be spaced from the acceptor booster 70 by a discontinuity such as an air gap 72; the acceptor booster 70 may further be capable of detonating another secondary high explosive mass (e.g., detonating cord 54) in operative association with it by means of the acceptor booster 70's own detonation. Thus, an acceptor booster 70 may continue/allow a detonation from a donor booster 56, even across a discontinuity, and may transmit the detonation to another secondary high explosive mass so as to continue/allow the detonation. Therefore, to continue/allow the detonation, it may be essential that an acceptor booster 70 detonate, and not deflagrate.
Ignition device 68 may be coupled to detonating cord initiator 52 and may provide a substantial amount of the energy to ignite detonating cord initiator 52. A signal (e.g., electrical, mechanical, etc.) may be sent from the surface 16 (e.g., shown on
With continued reference to
Gun subassembly 44 may comprise gun body 74. As illustrated, gun body 74 may be in the form of a cylindrical sleeve. Gun body 74 may comprise a plurality of charge holding recesses 48, which hold shaped charges 50. Each of shaped charges 50 may comprise TEX. The TEX may be present as compressed particles. TEX may be the sole explosive of the shaped charges 50 or may be mixed with other high-temperature explosives as discussed above. The TEX may be coated or uncoated as described above.
The plurality of shaped charges 50 may be arranged in a spiral pattern such that each of the shaped charges 50 may be disposed on its own level or height and may be individually detonated so that only one shaped charge 50 may be fired at a time. Alternate arrangements of the plurality of shaped charges 50 may be used, including cluster type designs wherein more than one shaped charge 50 may be at a same level and may be detonated at the same time. Upon ignition, shaped charges 50 may generate a jet that may penetrate casing 34, cement 36, and into subterranean formation 14, which are shown on
In some examples, downhole perforating system 10 may be used, at least in part, for a casing-conveyed perforating operation. In a casing-conveyed perforating operation, the shaped charges 50 and any other corresponding components may be conveyed on the casing 34 into the wellbore 32 for a desired duration until a perforation operation is to be initiated. At such time, the shaped charges 50 may be detonated as described above to conduct the perforation operation.
It should be clearly understood that the examples illustrated by
After the perforation has been formed, the perforation may be cleaned. TEX generates a quantity of detonation product gasses which is approximately 15% less than an equivalent mass of high-performance explosives (eg. HMX or RDX). Therefore, the in-gun pressure immediately after perforating is reduced relative to perforating with other high-performance explosives assuming a given post-detonation gas temperature. As such, the formed perforation may be cleaned by means of a dynamic underbalance, which would not have existed had a higher-quantity-gas generating explosive (e.g., HMX) been instead used. Moreover, the operational pressure window for perforation cleanup may be expanded.
In some examples, oilfield perforating includes the cutting of oilfield equipment such as downhole tubulars and the like. Referring now to
It should be clearly understood that the example illustrated by
In other examples, the TEX explosive may be used for other cutting or severing operations such as drill collar severing. Additionally, the TEX explosive may also be used in other wellbore applications and operations as would be readily apparent to one of ordinary skill in the art. For example, the TEX may be used to provide actuation for a release mechanism such as with a gun hangar, inter-gun release tool, etc. TEX may also be used as a propellant component for a setting tool, power charge, gas/pressure generator, a stimulation tool, and the like. TEX may also be used with time delays, fuzes, shock tubes, mild detonating fuses, explosively actuated valves or other components, vent chamber, etc. The TEX explosive may be used in a wide variety of applications requiring an explosive with high thermal stability and sufficient energy output.
It is also to be recognized that the disclosed methods and systems may also directly or indirectly affect the various downhole equipment and tools that may contact components of the methods and systems disclosed herein. Such equipment and tools may include, but are not limited to, wellbore casing, wellbore liner, completion string, insert strings, drill string, coiled tubing, slickline, wireline, drill pipe, drill collars, mud motors, downhole motors and/or pumps, surface-mounted motors and/or pumps, centralizers, turbolizers, scratchers, floats (e.g., shoes, collars, valves, etc.), logging tools and related telemetry equipment, actuators (e.g., electromechanical devices, hydromechanical devices, etc.), sliding sleeves, production sleeves, plugs, screens, filters, flow control devices (e.g., inflow control devices, autonomous inflow control devices, outflow control devices, etc.), couplings (e.g., electro-hydraulic wet connect, dry connect, inductive coupler, etc.), control lines (e.g., electrical, fiber optic, hydraulic, etc.), surveillance lines, drill bits and reamers, sensors or distributed sensors, downhole heat exchangers, valves and corresponding actuation devices, tool seals, packers, cement plugs, bridge plugs, and other wellbore isolation devices, or components, and the like. Any of these components may be included in the methods and systems generally described above and depicted in
Provided are systems for oilfield perforating or cutting in accordance with the disclosure and the illustrated FIGs. An example system comprises a detonator; and a shaped charge comprising 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,9.03,11]-dodecane (“TEX”).
Additionally or alternatively, the system may include one or more of the following features individually or in combination. The system may further comprise a firing head subassembly comprising a detonating cord initiator comprising TEX. The system may further comprise bi-directional boosters comprising TEX. The system may further comprise a detonating cord comprising TEX. The system may further comprise a plurality a gun subassembly. The system may additionally comprise an explosive component selected from the group consisting of NONA, HMX, HNS, PETN, RDX, TATB, DAAF, PYX, NTO, DATB, HNAB, BRX, THKP, and any combinations thereof. The additional explosive component may be mixed with the TEX. The TEX may have a particle size of about 50 to about 500 microns. The TEX may have a particle size of about 0.01 to about less than 50 microns. The TEX may be coated. The system may not comprise an explosive component other than the TEX. The detonating cord initiator may comprise TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to about less than 50 microns. The system may further comprise a donor booster comprising TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to less than about 50 microns. The system may further comprise an acceptor booster comprising TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to less than about 50 microns.
Provided are systems for oilfield perforating in accordance with the disclosure and the illustrated FIGs. An example system comprises a firing head subassembly; a gun subassembly; and TEX.
Additionally or alternatively, the system may include one or more of the following features individually or in combination. The firing head subassembly may comprise a detonating cord initiator, wherein the detonating cord initiator comprises the TEX. The perforating system may further comprise bi-directional boosters comprising the TEX. The perforating system may further comprise a detonating cord comprising the TEX. The perforating system may further comprise a plurality of shaped charges comprising the TEX. The perforating system may additionally comprise an explosive component selected from the group consisting of NONA, HMX, HNS, PETN, RDX, TATB, DAAF, PYX, NTO, DATB, HNAB, BRX, THKP, and any combinations thereof. The additional explosive component may be mixed with the TEX. The TEX may have a particle size of about 50 to about 500 microns. The TEX may have a particle size of about 0.01 to less than about 50 microns. The TEX may be coated. The perforating system may not comprise an explosive component other than the TEX. The detonating cord initiator may comprise TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to about less than 50 microns. The system may further comprise a donor booster comprising TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to less than about 50 microns. The system may further comprise an acceptor booster comprising TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to less than about 50 microns.
Provided are systems for oilfield perforating in accordance with the disclosure and the illustrated FIGs. An example system comprises a detonating cord initiator; a detonating cord coupled to the detonating cord initiator; and a plurality of perforating gun subassemblies coupled to the detonating cord, wherein the plurality of perforating gun assemblies comprises a plurality of shaped charges, wherein the plurality of shaped charges comprises TEX.
Additionally or alternatively, the system may include one or more of the following features individually or in combination. The perforating system may further comprise a firing head subassembly and a gun subassembly. The firing head subassembly may comprise a detonating cord initiator, wherein the detonating cord initiator comprises the TEX. The perforating system may further comprise bi-directional boosters comprising the TEX. The perforating system may further comprise a detonating cord comprising the TEX. The perforating system may further comprise a plurality of shaped charges comprising the TEX. The perforating system may additionally comprise an explosive component selected from the group consisting of NONA, HMX, HNS, PETN, RDX, TATB, DAAF, PYX, NTO, DATB, HNAB, BRX, THKP, and any combinations thereof. The additional explosive component may be mixed with the TEX. The TEX may have a particle size of about 50 to about 500 microns. The TEX may have a particle size of about 0.01 to less than about 50 microns. The TEX may be coated. The perforating system may not comprise an explosive component other than the TEX. The detonating cord initiator may comprise TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to about less than 50 microns. The system may further comprise a donor booster comprising TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to less than about 50 microns. The system may further comprise an acceptor booster comprising TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to less than about 50 microns.
Provided are methods for oilfield perforating in accordance with the disclosure and the illustrated FIGs. An example method comprises lowering a perforating system into a casing of a wellbore, wherein the perforating system comprises TEX; detonating the TEX; and perforating the casing.
Additionally or alternatively, the method may include one or more of the following features individually or in combination. The detonating may comprise the sequential detonation of a plurality of shaped charges, wherein the plurality of shaped charges comprises the TEX. The plurality of shaped charges may comprise a booster charge and a main charge. The main charge may comprise TEX having a particle size of about 50 to about 500 microns. The detonating may comprise simultaneous detonation of a plurality of shaped charges. The method may further comprise allowing formation communication between a formation and the wellbore. The wellbore may comprise a temperature exceeding the anticipated time-duration rating for HMX (204° C. for 1 hr., 177° C. for 10 hr., 150° C. for 100 hr.). The method may further comprise cleaning the formed perforation by means of a dynamic underbalance, which would not have existed had a higher-quantity-gas generating explosive (e.g., HMX) been instead used. The perforating system may further comprise a firing head subassembly and a gun subassembly. The perforating system may further comprise a detonating cord initiator; a detonating cord coupled to the detonating cord initiator; and a plurality of perforating gun subassemblies coupled to the detonating cord, wherein the plurality of perforating gun assemblies comprises a plurality of shaped charges, wherein the plurality of shaped charges comprises TEX. The firing head subassembly may comprise a detonating cord initiator, wherein the detonating cord initiator comprises the TEX. The perforating system may further comprise bi-directional boosters comprising the TEX. The perforating system may further comprise a detonating cord comprising the TEX. The perforating system may further comprise a plurality of shaped charges comprising the TEX. The perforating system may additionally comprise an explosive component selected from the group consisting of NONA, HMX, HNS, PETN, RDX, TATB, DAAF, PYX, NTO, DATB, HNAB, BRX, THKP, and any combinations thereof. The additional explosive component may be mixed with the TEX. The TEX may have a particle size of about 50 to about 500 microns. The TEX may have a particle size of about 0.01 to less than about 50 microns. The TEX may be coated. The perforating system may not comprise an explosive component other than the TEX. The detonating cord initiator may comprise TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to about less than 50 microns. The system may further comprise a donor booster comprising TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to less than about 50 microns. The system may further comprise an acceptor booster comprising TEX having a particle size of about 50 to about 500 microns and TEX having a particle size of about 0.01 to less than about 50 microns.
The preceding description provides various examples of the systems and methods of use disclosed herein which may contain different method steps and alternative combinations of components. It should be understood that, although individual examples may be discussed herein, the present disclosure covers all combinations of the disclosed examples, including, without limitation, the different component combinations, method step combinations, and properties of the system. It should be understood that the compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps. The compositions and methods can also “consist essentially of or “consist of the various components and steps. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces.
For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited. In the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values even if not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.
One or more illustrative examples incorporating the examples disclosed herein are presented. Not all features of a physical implementation are described or shown in this application for the sake of clarity. Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned, as well as those that are inherent therein. The particular examples disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown other than as described in the claims below. It is therefore evident that the particular illustrative examples disclosed above may be altered, combined, or modified, and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein.
Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the following claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2019/013624 | 1/15/2019 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62631764 | Feb 2018 | US |
