CN112105793A

CN112105793A - Multi-stage single-point short gun perforating device for oil field application

Info

Publication number: CN112105793A
Application number: CN201980031375.5A
Authority: CN
Inventors: C·蒙坦尼兹; D·W·普拉特
Original assignee: Owen Oil Tools LP
Current assignee: Owen Oil Tools LP
Priority date: 2018-07-25
Filing date: 2019-07-25
Publication date: 2020-12-18
Also published as: AU2019311107A1; MX2020011438A; EP3759312A1; CA3098041A1; US20210207459A1; WO2020023774A1

Abstract

An apparatus for perforating an unconventional subterranean formation includes a charge holder having a passage along a major axis, a detonator device positioned in the passage, and a plurality of shaped charges supported by the charge holder, the shaped charges being circumferentially distributed along a common plane transverse to the major axis. Each shaped charge is formed of at least one charge case, explosive material disposed in the charge case, and a liner enclosing the explosive material in the charge case. All shaped charges are directly energetically coupled to a detonator.

Description

Multi-stage single-point short gun perforating device for oil field application

Technical Field

The present disclosure relates to apparatus and methods for completing a well.

Background

Hydrocarbons, such as oil and gas, are produced from cased wellbores intersecting one or more hydrocarbon reservoirs in the formation. These hydrocarbons flow into the wellbore through perforations in the cased wellbore. Perforations are typically made using a perforating gun loaded with shaped charges. The perforating gun is lowered into the wellbore by a power cable, slickline, tubing, coiled tubing, or other conveyance device until it is proximate the hydrocarbon producing formation. Thereafter, a surface signal actuates a firing head associated with the perforating gun, which then detonates the shaped charges. The projectiles or jets formed by the detonation of the shaped charges penetrate the casing, thereby causing formation fluids to flow through the perforations into the production string.

Conventional perforation tools produce a shot pattern that places the tunnel primarily along the axial length of the wellbore. The present disclosure presents unconventional perforation tools, such as hydraulic fracturing, that may enhance completion activities.

Disclosure of Invention

In some aspects, the present disclosure provides an apparatus for perforating a subterranean formation. The apparatus may include: a charge holder having a channel along a long axis; a detonator device located in the passage; and a plurality of shaped charges supported by the charge holder and circumferentially distributed along a common plane transverse to the long axis. Each shaped charge is formed of at least one charge case, explosive material disposed in the charge case, and a liner enclosing the explosive material in the charge case. All shaped charges are directly energetically coupled to a detonator.

In a further aspect, the present disclosure provides a method for perforating an unconventional subterranean formation. The method may include positioning the apparatus in a wellbore and firing the apparatus.

The foregoing examples of features of the present disclosure have been summarized rather broadly in order that the detailed description that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will form the subject matter of the claims appended hereto.

Drawings

For a detailed understanding of the present disclosure, reference should be made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, in which like elements are given like reference numerals, and wherein:

FIG. 1 is a schematic cross-sectional view of a portion of a horizontal well in which a perforating gun is positioned in accordance with an embodiment of the present disclosure;

figures 2A and 2B illustrate shot patterns obtained by the perforating gun shown in figure 1.

FIG. 3A is an isometric view of a charge holder made according to one embodiment of the present disclosure;

FIG. 3B is an isometric view of a charge holder made according to one embodiment of the present disclosure;

fig. 4 is a schematic cross-sectional view of a carrier according to one embodiment of the present disclosure;

FIG. 5 is a schematic cross-sectional view of one embodiment of an apparatus of the present disclosure positioned in a well penetrating a subterranean formation;

FIG. 6 is a schematic side view of a perforating gun using one or more scallops according to one embodiment of the present disclosure;

7A-7C illustrate various firing arrangements for perforating guns made in accordance with embodiments of the present disclosure;

8A, 8B illustrate a segmented casing of a perforating gun made in accordance with an embodiment of the present disclosure;

FIG. 9 is an exemplary shaped charge that may be used with a perforating gun according to embodiments of the present disclosure;

FIG. 10 schematically illustrates a single detonator in energetic contact with a plurality of shaped charges on a single plane, in accordance with an embodiment of the present disclosure; and

figure 11 schematically illustrates a pocket for receiving shaped charges according to an embodiment of the invention.

Detailed Description

Aspects of the present disclosure provide methods and related perforation tools for completing unconventional formations (e.g., hydrocarbon bearing shale formations). For purposes of this disclosure, an "unconventional" formation is typically one that has a permeability of less than 10 millidarcies (mD). Many "unconventional" formations have permeabilities between 1 nadaxine (nD) and 1 millidarcy (mD).

Referring to FIG. 1, a horizontal section of a wellbore 10 is shown with perforating

guns

50, 60 positioned therein according to an embodiment of the present disclosure. Each

gun

50, 60 includes a shaped charge 70. The gun 50 has shaped charges circumferentially distributed in a plane 72. The gun 60 has shaped charges distributed circumferentially on two

planes

74, 76. The

planes

72, 74, 76 of FIG. 1 are transverse to the long axis 11 of the wellbore 10, e.g., the axis of fluid flow along the wellbore 10.

The number of shaped charges 70 on each plane may vary to suit a particular situation. A plane may include only one shaped charge 70 or four or more shaped charges 70. In some cases, two or three shaped charges 70 may be used. Although not required, the shaped charges 70 are generally evenly distributed along their respective planes; for example, two shaped charges 70 are 180 degrees apart, three shaped charges 70 are 120 degrees apart, four shaped charges 70 are 90 degrees apart, and so on. The maximum number of shaped charges 70 in a particular plane depends in part on the size of the shaped charges, the charge retention structure, and the carrier tube.

FIG. 2A shows a "shot pattern" 52 that may be obtained by gun 50 (FIG. 1), assuming four shaped charges 70 are used. In one embodiment, the perforating gun 50 is configured to form a shot pattern 52 having limited penetration perforations 80. For example, perforations 80 extend through casing 12 and cement sheath 14, but extend only minimally, if at all, into surrounding formation 16.

Fig. 2B shows a "shot pattern" 62 that may be obtained by the gun 60 (fig. 1) assuming four shaped charges 70 are used in each

plane

74, 76. The shot pattern 62 includes a first set of visible perforations 64 and a second set 66 of hidden perforations 80. It should be noted that the shaped charges 70 of each

plane

74, 76 are 45 degrees out of phase with each other.

FIG. 3A shows one non-limiting embodiment of a charge holder 90 for use with gun 50 (FIG. 1). The charge holder 90 may be a cylinder that includes a cavity 92, with the shaped charges 70 (FIG. 1) seated in the cavity 92. In one arrangement, the cavities 92 may be circumferentially distributed pockets formed on the outer surface 91 of the body 93. Each cavity 92 may be defined by an inner landing surface 95 against which shaped charges 70 (fig. 1) are landed against. For the seating surface 95, certain embodiments may use a cup shape or a cone shape. That is, landing surface 95 may generally follow the curvature or angle of the body of shaped charge 70 (FIG. 1); that is, the landing surface 95 is complementary to the body of the shaped charge 70 (FIG. 1). In some embodiments, landing surface 95 may limit radially inward and/or lateral movement of shaped charges 70 (FIG. 1). The charge holder 90 may be formed of steel or molded from a non-metallic material such as plastic. The shaped charges 70 (FIG. 1) may be press fit into the cavities 92 or secured in the cavities 92 using fastening elements (not shown) such as clips, tabs, etc.

For arrangements using four shaped charges 70 (FIG. 1), the charge holder 90 may include four circumferentially distributed cavities 92, all arranged along the same plane 72 (FIG. 1). One or more of the channels 94 may be used for deployment equipment, such as detonators (not shown) and/or wiring (not shown). The passage 94 may be an internal bore that extends partially or completely through the body 93. In some embodiments, charge holder 90 may be formed as a unitary body formed of metal, plastic, composite, ceramic, and/or other suitable materials. In some embodiments, the charge holder 90 may be formed of a material that disintegrates or is consumed during use.

In an embodiment, the body 93 of the charge holder 90 may be a substantially solid cylinder. For purposes of this disclosure, a cylinder is considered "solid" if at least twenty-five percent of the radius 101 from the center of the channel 94 to the outer surface 91 is formed of solid material. Other suitable embodiments may have at least forty percent, at least fifty percent, or at least seventy-five percent solid material forming the radius 101. References in this disclosure to "solid" cylinders are in contrast to "hollow" cylinders. The wall of the hollow cylinder constitutes less than 40% of the radius 101. Conventional pipes or tube members are representative of hollow cylinders.

FIG. 3B shows one non-limiting embodiment of a charge holder 96 of the gun 60 (FIG. 1)). The charge holder 96 is similar to the charge holder 90 (FIG. 3A). However, the cavities 92 are arranged on both planes 74, 76 (fig. 1). In this embodiment, the cavities 92 of each

plane

74, 76 are 45 degrees out of phase with each other.

Figure 4 shows a carrier 100 (figure 4)) that may be used with the perforating

guns

50, 60. Carrier 100 includes apertures 102 for receiving charge holders, such as charge holder 90. In addition, a circumferential groove 94 is formed on the outer surface to provide a weakened wall section that allows the perforating jet to exit the perforating gun with less energy loss. The groove 94 extends completely around the carrier 100. Thus, no angular/circumferential alignment between the shaped charges 70 and the circumferential grooves 94 is required. Rather, the carrier 100 only requires an internal stop 97 to axially align the shaped charges 70 with the recesses 94. By "axially aligned" it is meant that shaped charges 70 and circumferential recess 74 are in the same plane 72 (FIG. 1) transverse to long axis 11 (FIG. 1).

It should be noted that the charge holder 90 may be "free floating" radially in the apertures 102 of the carrier 100. By "free floating" it is meant that the charge holder 90 can move laterally, or transverse to the long axis 11 (FIG. 1). The charge holder 90 is limited in this lateral movement only by the inner walls defining the aperture 102. There is no structure connected to the charge holder 90 that restricts lateral movement.

Referring to fig. 3A, during a hydraulic fracturing operation, it may be advantageous to arrange a plurality of shaped charges along a plane. Shaped charges 70 (FIG. 1) form perforations 80 along the same plane 72 (FIG. 1). Thus, the hydraulic fracturing fluid 110 exits the perforations 80 at the same axial location but at a different circumferential location. Directing the fracturing fluid 110 in this manner may minimize the tortuosity of the "fracturing" event and minimize the pressure required to create the formation fracture and allow for better proppant placement.

From the foregoing, it should be appreciated that perforating guns according to the present disclosure can be relatively short; for example, less than one foot. In addition, the use of

charge holders

90, 96 may eliminate the need for end plates or other similar structures to support conventional charge holding structures.

The perforation tool described above may be used to complete a hydrocarbon production well. Referring to fig. 5, a well configuration and/or hydrocarbon recovery facility 101 is shown positioned above an associated subterranean formation 102. Formation 103 is an unconventional formation. As described above, the nature of the unconventional formation 103 is that of stony earth, typically of the shale type, which is highly impermeable; i.e., permeability less than ten millidarcies (mD).

The facility 101 may include known equipment and structures, such as a drilling rig 106 and a production structure 108. The production structure 108 may include casing, liner, cement, and other wellbore equipment. A work string 110 is suspended within the wellbore 10 from the drilling rig 106. The work string 110 may include drill pipe, coiled tubing, wireline, slickline, or any other known conveyance component. The work string 110 may include telemetry circuitry or other signal/power transmission media that establishes one-way or two-way telemetry communication. The telemetry system may have a surface controller (e.g., power supply) 112 adapted to transmit electrical signals via a suitable cable or signal transmission line.

The perforating gun train 140 is shown in a deviated section 142 of the wellbore 10. The gun train 140 may include one or more guns according to the present disclosure, such as

guns

50, 60. By deviated, it is meant that a section of the wellbore 10 is not vertical. In some cases, the skew with respect to the vertical reference may be between 1 and 90 degrees (horizontal) or greater. In embodiments, the skew may be greater than thirty degrees, greater than forty-five degrees, or greater than sixty degrees. For reference, a deflection of less than 90 degrees will point the segment 142 downward, and a deflection of greater than 90 degrees will point the segment 142 upward. "pointing" refers to the direction in which the wellbore 10 is drilled.

When fired, the perforating gun train 140 creates one or more openings, as shown in figures 2A and/or 2B.

It should be understood that the teachings of the present disclosure are susceptible to numerous modifications and embodiments. Non-limiting variations are described below.

As mentioned above, the present disclosure is not limited to any particular number of shaped charges per plane. A plane may include only one shaped charge, two shaped charges, three shaped charges, or four or more shaped charges. Also as discussed above, although not required, the shaped charges may be evenly distributed along their respective planes; for example, two shaped charges are 180 degrees apart, three shaped charges are 120 degrees apart, four shaped charges are 90 degrees apart, and so on.

Referring to fig. 6, in certain embodiments, the carrier 100 may include one or more scallops 160 to reduce wall thickness. The scallops 160 are in contrast to the circumferential grooves 94 (fig. 4), where the scallops 160 are a localized reduction in the wall thickness of the carrier 100. Shaped charge(s) 70 may be aligned with scallop(s) 160 using a key 162 secured to charge holder 90, key 162 being seated within a groove or keyway 164 formed along the inner surface of carrier 100. Thus, when key 162 is seated in keyway 164, there is circumferential alignment between shaped charge(s) 70 and scallop(s) 160. When the charge holder 90 abuts the internal stop 97, the scallop(s) 160 are axially aligned with the shaped charges 70. It should be understood that key 162 and keyway 164 are merely illustrative examples of alignment members that may be used to circumferentially align shaped charge(s) 70 with scallop(s) 160. Other alignment members may use snap rings/grooves, pins/holes, etc.

Referring to fig. 7A-7C, different arrangements of detonating the shaped charges 70 are shown. In these arrangements, it should be understood that a single detonator detonators detonates all of the shaped charges 70 in a common plane. Furthermore, in these arrangements, all of the shaped charges 70 are directly energetically coupled to the detonator. By "direct energy coupling" is meant that explosive energy from the detonator is transferred to the shaped charges 70. The shaped charges 70 may or may not be in physical contact with the detonator, but are close enough that the energy released by the detonator detonators detonates the shaped charges 70. Thus, in direct energy coupling, no intervening energy elements external to the shaped charges are used to transfer detonation from the detonator to the shaped charges.

In fig. 7A, shaped charge 70 is detonated directly by detonating cord 170. The detonating cord 170 can be initiated by a detonator 172, the detonator 172 being activated directly or indirectly by a signal transmitted from the surface. In FIG. 7B, shaped charge 70 includes booster 76 detonated by detonating cord 170. Booster 176 may be inside shaped charge 70 rather than a separate element. In fig. 7C, the shaped charges 70 are detonated directly by the detonator 172, and the detonator 172 may be activated directly or indirectly by a remote signal. Optionally, the shaped charge 70 may include an internal booster 176. Thus, it should be understood that a detonating device is any device that releases sufficient energy (e.g., thermal energy, shock waves, pressure waves, etc.) to be able to detonate a plurality of shaped charges 70, all of which lie in a common plane via direct energy coupling.

Figures 8A and 8B illustrate an embodiment of a segmented segment charge holder 90. Referring to fig. 8A, charge holder 90 may be a cylinder including three body segments 190. In one arrangement, each body section 190 is "pie-shaped," i.e., generally defined by two radii and a circular arc from the center. The surfaces aligned with each radius may be considered radial surfaces. The radial surfaces of each body section 190 abut each other such that when assembled, the body sections 190 form a solid cylinder. Each body section 190 has a cavity 192, which may be a pocket, formed on an outer surface 194 of the body section 190. Each cavity 192 may be defined by an inner landing surface 196 against which the shaped charge 70 (fig. 1) lands, and the inner landing surface 196 may be the same as the landing surface 95 (fig. 3A) previously described. Segmented charge holder 90 includes a central passage 200 for receiving a device for detonating shaped charges 70 (fig. 1), such as a detonating cord, booster charge, bi-directional booster charge, detonator, device providing high-order detonation, and the like.

Figure 8A shows a charge holder 90 having three body segments 190, while figure 8B depicts an arrangement having four body segments 202. The

body sections

190, 202 may be molded from a non-metal, such as plastic. The

body sections

190, 202 may be held together into a cylinder by any suitable means. For example, O-rings may be fitted into one or more grooves 205 formed on a body section, such as body section 202. Additionally or alternatively, other retaining members, such as clips, fasteners, adhesives, or the like, may be used to secure the

body sections

190, 202 to one another.

Additionally, in some embodiments, the

body segments

190, 202 may be casings for shaped charges; that is, an energetic material (not shown) may be disposed in the cavity 192 and then enclosed by a suitable liner (not shown). It should be appreciated that in such embodiments, the perforating tool eliminates the charge holder; that is, the shaped charges are self-supporting in the carrier. By "self-supporting" it is meant that the shaped charges can structurally support each other to maintain a desired relative orientation.

It should be emphasized that the perforating tool of the present disclosure is not limited to any particular shaped charge design or configuration. For better understanding only, one suitable shaped charge 70 that may be used with the perforating tool described above is shown in FIG. 9. The shaped charge 70 may have a frustoconical shaped charge case 224. The perforating charge case 224 is open at an outer end 230. A bushing 228 is disposed inside the shell 224, the bushing 228 having a generally conical or frustoconical configuration. Explosive material 234 is disposed between the liner 228 and the inner wall 226 of the casing 224. The perforating charge case 224 has an apex 236 at the closed end 238. Located near the apex 236 is an initiator 240 for initiating the explosive charge 234. In this configuration, it should be noted that apex 236 does not enclose detonator 240. As seen in fig. 10, apex 236 is shaped to be narrow enough to allow multiple shaped charges 70 to be arranged circumferentially on the same plane around detonator 240. Thus, in one aspect, the detonation surface may be defined by an outer surface. All of the shaped charges 70 are energetically coupled to the outer surface. While the outer surface may define a circumferential body, the outer surface may define other geometric shapes, such as squares, rectangles, ovals, triangles, and the like. Regardless of the geometry, such an outer surface has multiple energy couplings. Although apex 236 is shown as a concave surface, apex 236 may also be flat or have any other geometry.

It should be noted that for the embodiment of fig. 8A and 8B, the shaped charge 70 configured as in fig. 9 may be modified as described previously. That is, the body segments 190, 202 (fig. 8A, 8B) are perforating charge cases 224 (fig. 9), in which case they may be referred to as perforating charge case segments. Because the assembly of the

charge case segments

190, 202 forms a cylinder of shaped charges that can be inserted directly into the carrier 100 (FIG. 4), a separate structure, such as a charge tube or band, for holding the shaped charges is not required. That is, the shaped charges are considered to be self-supporting in the carrier 100 (fig. 4).

Non-limiting embodiments of a perforating tool having self-supporting shaped charges can include a carrier, a shaped charge assembly disposed in the carrier, and a detonating device disposed in the carrier. The shaped charge assembly may include a plurality of shaped charges. Each shaped charge may include a charge case, explosive material disposed in the charge case, and a liner enclosing the explosive material in the charge case. The shaped charges may be arranged circumferentially around the detonator such that all of the shaped charges are in the same plane, which is transverse to the long axis of the carrier. In addition, each charge case has a radial surface that substantially abuts a radial surface of an adjacent shaped charge. The perforating charge case is arranged to form a solid cylinder. Alternatively, a retaining member may be disposed about the shaped charges to secure the shaped charges to one another. Alternatively, the shaped charges may be directly energetically coupled with a detonator.

Referring to fig. 3A and 9, the landing surface 95 may generally follow the curvature or angle of the outer surface 250 of the charge case 224 of the shaped charge 70, as previously described. The seating surface 95 may be contiguous for some or all of the outer surface 250. For example, in some embodiments, the landing surface 95 may abut the landing surface 95 at least twenty-five percent of the linear distance 252 between the base 230 and the apex 232. In other embodiments, the abutment distance between the base 230 and the apex 232 may be at least forty percent, at least fifty percent, or at least seventy-five percent. In other embodiments, the seating surface 95 is fully contiguous and is only interrupted by an opening (not shown) through which at least the apex 236 is located in the channel 94 or channel 200 (fig. 8A). By "abutting" is meant that the landing surface 95 generally follows the curvature of the outer surface 250. No continuous physical contact is required. A similar percentage of the abutting distance may be used for the inner landing surface 196 shown in fig. 8A.

Fig. 11 shows the seating surface 95 associated with the

pockets

92, 192 described above. Seating surfaces 95, 196 terminate at an opening 193 through which apex 236 (fig. 9) enters channel 94 or channel 200 as previously described.

In the context of the present disclosure, detonation is a supersonic combustion reaction that can generate a shock wave and release thermal energy. High explosives (RDX, HMX, etc.) are materials that will detonate. A detonator is a device for triggering explosive materials, such as those in shaped charges or detonating cords. The detonator may be initiated mechanically or electronically.

The foregoing descriptions are directed to particular embodiments of the present disclosure for the purpose of illustration and explanation. However, it will be apparent to those skilled in the art that many modifications and variations to the above-described embodiments are possible without departing from the scope of the disclosure. It is therefore intended that the following claims be interpreted to embrace all such modifications and changes.

Claims

1. An apparatus for perforating a subterranean formation, the apparatus comprising:

a charge holder having a channel along a long axis;

an explosive device located within the channel; and

a plurality of shaped charges supported by the charge holder, the plurality of shaped charges circumferentially distributed along a common plane transverse to the long axis, wherein each shaped charge is comprised of at least one charge case, explosive material disposed in the charge case, and a liner enclosing the explosive material in the charge case, and wherein all of the shaped charges are energetically coupled directly to the detonator device.

2. The apparatus of claim 1, wherein the charge holder is solid.

3. The apparatus of claims 1 and 2, wherein the charge holder comprises a plurality of circumferentially distributed pockets formed on an outer surface of the charge holder, and wherein each pocket receives one of the plurality of shaped charges.

4. The apparatus of claim 3, wherein each pocket has a landing surface that is complementary to a body of the shaped charge received in the pocket.

5. The apparatus of claims 1-3, wherein at least fifty percent of a radius from a center of the channel to the outer surface is formed of a solid material.

6. The apparatus of claims 1-5, wherein the charge holder comprises a plurality of body segments.

7. The apparatus of claim 6, wherein the body segment of each segment is a perforating charge case of each shaped charge of the plurality of shaped charges.

8. The apparatus of claims 1 to 7, wherein the initiating device is a detonator responsive to a surface signal.

9. The apparatus of claims 1-7, wherein the initiation device is one of (i) a booster and (ii) a detonating cord.

10. The apparatus of claims 1-9, further comprising a carrier having a bore that receives the charge holder, the carrier having a circumferential groove extending completely around an outer surface, the circumferential groove being axially aligned with the plurality of shaped charges.

11. A method for completing an unconventional formation, the method comprising:

positioning a perforation tool in a section of a wellbore intersecting the unconventional formation, wherein the wellbore is deviated from a vertical reference, the perforation tool comprising:

a charge holder having a channel along a long axis;

an explosive device located within the channel; and

a plurality of shaped charges supported by the charge holder, the plurality of shaped charges circumferentially distributed along a common plane transverse to the long axis, wherein each shaped charge is comprised of at least one charge case, an explosive material disposed in the charge case, and a liner enclosing the explosive material in the charge case, and wherein all of the shaped charges are energetically coupled directly to the detonator; and

firing the perforation tool to form at least one opening in the unconventional formation.

12. The method of claim 11, further comprising:

pumping a fracturing fluid through the at least one opening to fracture the formation.

13. The method of claims 11-12, wherein the deflection is at least forty-five degrees relative to the vertical reference.

14. The method of claims 11-13, wherein the unconventional formation has a permeability of less than 10 millidarcies (mD).