Hollow-charge system with multi-composition insert

Abstract

System for creating a perforation in an underground formation, comprising: a shaped charge consisting of a casing; an insert and a high-explosive pellet, which is positioned between the housing and the insert, wherein the insert is formed from a mixture of powder materials extending along an inside of the housing from an apex to a bottom part, wherein the mixture of powder material is varied from the apex to the lower part of the insert, and wherein the insert has a continuity that satisfies d(alpha) / dx and d(rho) / dx, where alpha is the half-angle of the insert, rho is the insert density and x is the axial distance along the insert.

Description

GENERAL STATE OF THE ART

[0001] After drilling and casing an oil or gas well, the well is opened to the surrounding formation to allow oil or gas to enter. This is achieved by perforating the casing and the rock formation behind it using shaped charges. A shaped charge generally consists of a highly explosive material sandwiched between a casing and a liner. Part of the liner forms a jet that is propelled away from the casing when the shaped charge detonates. This jet is forced through the casing and into the formation, creating a perforation that facilitates the ingress of oil and / or gas.

[0002] US 2004 / 0200377A1 shows an insert for an explosive shaped charge formed from a mixture of pulverized metals into three or more conical sections, the third conical section having a lower density than the first and second sections.

[0003] US patent 2012 / 0234194A1 discloses an insert comprising a powder, the powder in turn comprising a mixture of particles. The particles comprise a core material, a first reactant material in close contact with the core material, and a second reactant material in close contact with the first reactant.

[0004] In addition, US 2003 / 0183113A1 shows a precursor liner and a primary liner, both pressed into a housing. The precursor liner is pressed into a vertex of the primary liner and, upon detonation, is intended to form an initial, very fast-moving precursor jet to open a path through the fluid of a borehole ring for the subsequent primary jet.

[0005] Furthermore, US patent 2008 / 0289529A1 discloses a device with an insert for penetrating a target. The insert comprises at least one insert element made of a penetrating material and one insert element made of a reactive material, and may also include at least one insert element that is neither made of a penetrating nor a reactive material.

[0006] US Patent 4,498,367 A specifies parameters for selecting materials to be used as liners in shaped charges in order to transfer the greatest amount of energy to the explosive jet. Multilayer metal liners in shaped charges for oil well perforators or other applications are selected to maximize the penetration effect of the explosive jet based on four parameters. SUMMARY

[0007] In general, a system and method are provided to simplify the perforation of a casing and formation. A shaped charge is formed using a casing, an liner, and a high-explosive material located between the casing and the liner. The liner is formed from a powder material, such as a powdered metal. Parameters of the liner between its apex and base can be selectively varied to provide a desired liner velocity and mass upon detonation of the high-explosive material.

[0008] However, many modifications are possible without substantially deviating from the teachings of this disclosure. Accordingly, such modifications shall be included within the scope of this disclosure as defined in the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Certain embodiments of the disclosure are described below with reference to the accompanying drawings, where identical reference numerals denote identical elements. It is understood, however, that the accompanying figures are intended to illustrate the various implementations described herein and are not meant to limit the scope of the various technologies described herein, and: Fig. Figure 1 is a schematic illustration of an example of a perforation system comprising a plurality of shaped charges inserted into a borehole, according to an embodiment of the disclosure; Fig. Figure 2 is a cross-sectional view of an example of a shaped charge according to an embodiment of the disclosure; Fig. Figure 3 is a cross-sectional view of another example of a shaped charge according to an embodiment of the disclosure; and Fig. Figure 4 is a cross-sectional view of another example of a shaped charge according to an embodiment of the disclosure. DETAILED DESCRIPTION

[0010] The following description includes numerous details to facilitate an understanding of some embodiments of the present disclosure. However, it is clear to an average person skilled in the art that the system and / or method can be implemented without these details and that numerous variations or modifications of the described embodiments are possible.

[0011] The disclosure herein generally includes a system and a method that simplify perforation, such as the perforation of a casing and formation to increase the production of an oil and / or gas well. The perforation can be carried out using a well-bore gun assembly deployed at the bottom of a well by means of a suitable through-hole. The well-bore gun assembly has a gun body designed to hold a plurality of shaped charges oriented outwards to create perforations in the surrounding formation upon detonation of the shaped charges.

[0012] Each shaped charge can be formed with a casing, an liner, and a high-explosive material sandwiched between the casing and the liner. The liner is formed from metallic and / or non-metallic powder material. Upon detonation of the high-explosive material, a portion of the liner is propelled as a jet that penetrates the casing and the surrounding formation. Jet properties, such as velocity and mass, can be adjusted by varying one or more liner properties between the liner's apex and lower portion, such as one or more composition parameters. For example, the density of the powder used to form the liner can be selectively varied between the apex and lower portion to provide a desired liner velocity and mass upon detonation of the high-explosive material.However, additional or other composition parameters of the insert can also be varied to achieve a desired perforation. Examples of these other composition parameters include the diameter distribution of the powder particles, hardness, ductility, porosity, and abrasiveness.

[0013] In one embodiment, the insert is formed from a powder material having a composition that varies between the apex and the lower part of the insert. Examples of the powder material include various metal powder materials, although other powder materials can be used in the mixture. In some embodiments, ceramic powders or other non-metal powder materials can be added to vary the powder material mixture between the apex and the lower part of the insert. Depending on the specifics of the application and / or environment, various powder metal mixtures, containing metals alone or combinations of metals and non-metals, can be used between the insert apex and the insert lower part.

[0014] The variable mixture of powder metal / powder material along the insert can be used to optimize the performance of oilfield perforators. For example, varying the composition parameters along the insert can be used to achieve deeper penetration, a larger casing entry hole diameter, increased casing hole diameter, and other improvements related to the well gun exit hole diameter and casing / formation penetration characteristics. In some embodiments, the mixture of powder material at the first part or apex of the insert, compared to the mixture of powder material through the remainder of the insert (called Mixture 2), can be formed with a different powder mixture (called Mixture 1), or vice versa.

[0015] With general reference to Fig. Figure 1 illustrates an example of a perforation system 20 deployed in a borehole 22 via a transmission 24. In this example, the borehole 22 extends from a surface area 28 into an underground formation 26 and is lined with a casing 30. The perforation system 20 includes a borehole gun 32, which has a borehole gun body 34. The borehole gun body 34 can have a variety of structures and can be constructed with many types of components. A variety of shaped charges 36 are attached to the borehole gun body 34, and each of the shaped charges 36 is oriented outwards from the gun body 34.

[0016] The shaped charges 36 are connected to a detonation system 38, which includes a detonation control 40 that provides signals to a detonator or detonators 42 to initiate the detonation of the shaped charges 36. In many applications, the detonation system 38 can use a detonator 42 in the form of a detonating cord, which is appropriately positioned to initiate the detonation of the shaped charges 36. If the detonator 42 includes a detonating cord, the cord is guided to the shaped charges 36, and portions of the cord are set in conjunction with explosive material located within the shaped charges 36. In some applications, the shaped charges 36 are placed in a stepped pattern along the borehole gun body 34 and connected by the detonator / detonating cord 42, which is guided back and forth between the stepped shaped charges 36. The detonating cord enables a desired, controlled detonation of the multitude of shaped charges.Upon detonation, the shaped charges 36 explode, producing a jet of material that is propelled outwards to create perforations 44 extending through the casing 30 and into the surrounding subsurface formation 26. The number and arrangement of the shaped charges 36 can vary depending on the parameters of a given perforation application. Furthermore, the shaped charges 36 can be detonated in separate groups; or multiple borehole guns 32 can be used to perforate different zones of the subsurface formation 26.

[0017] With general reference to Fig. Figure 2 illustrates an example of one of the shaped charges 36. In this embodiment, the shaped charge 36 comprises a casing 46, an liner 48, and a high-explosive material 50, e.g., a high-explosive pellet, positioned between the casing 46 and the liner 48. The liner 48 generally extends between a first part or apex 52 and a second part or lower part 54. For example, the liner 48 may be cup-shaped, with the apex 52 forming the bottom of the cup and the lower part 54 forming the rim of the cup. The liner 48 is formed with a powder material 56 that has properties that change between the apex 52 and the lower part 54. However, in some applications, non-powder material may also be combined in the liner 48 to help provide the changing property(ies).

[0018] For example, the insert 48 can be designed such that the powder material 56 exhibits differences in composition parameters, e.g., powder density or other material properties, from the apex 52 to the lower part 54. These differences in material properties can be selected to optimize or otherwise adjust the jet velocity and jet mass of the insert 48 upon detonation of the explosive material 50. The changes in composition parameters can be achieved by using a variety of powder material mixtures, e.g., blends, between the apex 52 and the lower part 54. In some applications, the powder material 56 can have a changing proportion of materials along the axis of the insert 48 (i.e., varying between the apex 52 and the lower part 54) to achieve a desired continuity of insert properties, e.g.,To achieve continuity of density or mass with a corresponding desired jet velocity and jet mass, the changing properties, e.g., changing material properties, along the insert 48 can be achieved through a variety of powder material techniques. However, the insert 48 can also be produced by three-dimensional (3D) printing techniques, which allow for variation of the material properties, e.g., variation of the material composition parameters, in different areas of the insert 48. For example, 3D printing techniques can be used to control and vary the porosity along the insert 48 to obtain desired jet properties.

[0019] For example, the powder material 56 used to form the liner 48 can be a metal powder material. The metal powder material can be composed of various mixtures of metal powders (or metal and non-metal powders), depending on the desired perforation properties for a given application. Examples of metal powders include tungsten (W) powder, copper (Cu) powder, lead (Pb) powder, titanium (Ti) powder, and other metal powders. The various metal powders can be mixed in many different compositions, and these compositions can be varied between the apex 52 and the lower part 54 of the liner 48. The composition of the metal powder material 56 and the variations in composition between the apex 52 and the lower part 54 are selected to achieve different perforation properties upon detonation of the explosive material 50.

[0020] The powder material composition and the change in powder material composition parameters between the apex 52 and the lower part 54 can vary considerably, depending on the overall design of the shaped charge 36, the casing 30, the rock type in the formation 26, and various other system and environmental parameters. Different mixtures of powder materials exhibiting varying powder material densities, diameter distributions, hardness properties, ductility properties, and / or abrasiveness properties can be used to achieve the desired perforations. It should also be noted that the powder material 56 may include non-metallic powder components.For example, ceramic powders or other non-metallic powders can be used to form parts of the insert 48, or they can be mixed with the metal powders to create desired material properties and changes in these properties that move from the apex 52 to the lower part 54. Powder materials with different densities, such as tungsten powder and ceramic powder, can be used in varying concentrations along the insert to create parts of the insert 48 with lower and higher densities.

[0021] With general reference to Fig. Figure 3 illustrates another embodiment of the shaped charge 36. In this embodiment, the insert 48 is produced from powder material 56 having different compositions, which moves from the apex 52 to the lower part 54. The insert 48 is produced with a plurality of individual segments 58, wherein at least some of the individual segments 58 have different material compositions relative to one another. The individual segments 58 can each be formed from different compositions of metal and non-metal powder, as discussed above, in order to achieve desired perforation properties. For example, segments 58 at or near the apex 52 can be made of powder materials with lower or higher density (e.g.,Powder materials with lower or higher concentrations of low-density components (such as tungsten powder or ceramic powder) are formed to achieve a desired jet velocity and jet mass upon detonation of the explosive material 50. Depending on the application, the insert 48 can contain two, three, four, or more different metal and / or non-metal powder material mixtures moving from the apex 52 to the lower part 54. The contents and arrangement of these segments 58 can be adapted depending on the desired perforator performance at any given target.

[0022] In the Fig.In the illustrated embodiment 4, the insert 48 is produced with powder material 56, which has a material composition that varies continuously from the apex 52 to the lower part 54. This continuous variation in material composition can be based on varying any of a multitude of parameters that move between the apex 52 and the lower part 54 of the insert 48. For example, the density of the powder material 56 forming the insert 48 can be varied continuously in an axial direction along the insert 48. In the illustrated example, the density of the insert 48 varies continuously from a low-density region 60 located at the apex 52 to a higher-density region 62 located at the lower part 54.The density of the powder material 56 and / or other composition parameters can be varied to different degrees and in different directions, depending on the desired properties of the jet produced by the detonation of the explosive material 50 from the insert 48.

[0023] As discussed above, the powder material 56 can comprise a variety of powder materials, such as tungsten, copper, lead, titanium, ceramics, and / or other types of powder materials. Furthermore, the powder material 56 can comprise a binder formed as a coating or other type of layer on the powder materials used to form the insert 48. The concentration and / or mixture of components can also be varied throughout individual segments 58 of the insert or according to other patterns between the apex 52 and the lower part 54 of the insert 48.

[0024] If the insert 48 is created from individual segments 58, certain compositions of the segments can produce sudden changes in density / mass, creating interruptions in the jet resulting from the detonation of the explosive material 50. In some applications, these interruptions may be beneficial, while in others they can be reduced or minimized by progressively engaging adjacent insert segments 58. For example, the multitude of segments 58 can be progressively matched from the apex 52 to the lower part 54. Depending on the application, various structural modifications can be made to the insert 48 to compensate for the varying parameters of the powder material 56 between the apex 52 and the lower part 54.

[0025] If, for example, the variable parameter is density, the thickness of the insert 48 can be varied with the changing density. In one embodiment, the region of the insert 48 with lower density is thinner, and the region of the insert 48 with higher density is thicker to maintain beam continuity. In some applications, interruptions in the formed beam can be minimized by designing the insert 48 to have a continuity that satisfies d(alpha) / dx and d(rho) / dx, where alpha is the half-angle of the insert, rho is the insert density, and x is the axial distance along the insert 48.

[0026] The insert 48 can be manufactured in many sizes and structures with various patterns and mixtures of powder material compositions. Furthermore, the insert can be combined with many types of casings and explosive materials to create different types of shaped charges and achieve desired perforation characteristics. The number and arrangement of the shaped charges can also be selected according to the parameters of the perforation application and the structure of the borehole gun array. The detonation system and sequence can also vary from one application to another.

[0027] Variation in the structure and / or composition of the shaped charge insert can be used to simplify perforation in many borehole applications. The shaped charges described herein can be used in boreholes drilled in the Earth's surface and in underwater boreholes. However, the shaped charges and their inserts can also be used in non-borehole applications where perforations are formed through and / or into a variety of materials. The variable insert properties can be used to obtain the desired beam for optimized perforation performance in many types of applications.

[0028] Although some embodiments of the disclosure have been described in detail above, a person skilled in the art will recognize that many modifications are possible without substantially departing from the teachings of this disclosure. Accordingly, such modifications are to be included within the scope of this disclosure as defined in the claims.

Claims

[1] System for creating a perforation in an underground formation, comprising: a shaped charge consisting of a casing; an insert and a high-explosive pellet, which is positioned between the housing and the insert, wherein the insert is formed from a mixture of powder materials extending along an inside of the housing from an apex to a bottom part, wherein the mixture of powder material is varied from the apex to the lower part of the insert, and wherein the insert has a continuity that satisfies d(alpha) / dx and d(rho) / dx, where alpha is the half-angle of the insert, rho is the insert density and x is the axial distance along the insert. [2] System according to claim 1, wherein the powder material is a powder metal material and the insert is formed from individual segments of powder metal materials having different material compositions that vary from the apex to the lower part. [3] System according to claim 1, wherein the powder material is a powder metal material and the insert is formed by a continuous variation of the mixture of powder materials from the apex to the lower part. [4] System according to claim 1, wherein the powder material of the insert has at least two different metal material compositions from the apex to the lower part. [5] System according to claim 1, wherein the powder material of the insert has at least three different material compositions from the apex to the lower part. [6] System according to claim 1, wherein the powder material of the insert has at least four different material compositions from the apex to the lower part. [7] System according to claim 1, further comprising a borehole gun body, wherein the shaped charge is attached to the borehole gun body. [8] System according to claim 1, wherein a powder with a different density relative to an average density of the mixture of powder materials is added to change the density of the insert in a specific area or areas of the insert. [9] Procedures, comprehensive: Placing a high-explosive pellet in a shaped charge casing; using a powdered metal material to create a liner that has a shape with an apex and a base; Adjusting the composition of the powder metal material from the apex to the lower part, where the deposit has a continuity that satisfies d(alpha) / dx and d(rho) / dx, where alpha represents the half-angle of the insert, rho the insert density, and x the axial distance along the insert; Placing the insert against the high-explosive pellet so that the high-explosive pellet is held between the insert and the shaped charge casing to create a shaped charge. [10] Method according to claim 9, wherein the fitting comprises creating an area of ​​the insert with a lower density. [11] Method according to claim 9, wherein the fitting comprises the use of connected, individual segments of powder metal material having different composition parameters which are varied from the apex to the lower part. [12] Method according to claim 9, wherein the adjustment comprises adjusting a composition parameter of the powder metal material, which is varied continuously from the apex to the lower part. [13] Method according to claim 9, further comprising a low-density powder to create areas of lower density in the insert. [14] The method of claim 9, further comprising forming the powder metal material with ceramic powder to create areas of lower density. [15] Method according to claim 9, further comprising attaching the shaped charge to a borehole gun body; moving the borehole gun body and the shaped charge downwards into a borehole; and detonating the shaped charge to create a perforation. [16] Method according to claim 9, wherein the use comprises forming the insert by three-dimensional printing. [17] Procedures, including: Forming a shaped charge with a casing; a liner formed from a powdered metal material and a high explosive material positioned between the liner and the casing; and Adjusting the jet velocity and jet mass of the insert by varying a composition parameter of the insert between an apex and a lower part of the insert, wherein the insert has a continuity satisfying d(alpha) / dx and d(rho) / dx, where alpha is the half-angle of the insert, rho is the insert density, and x is the axial distance along the insert. [18] Method according to claim 17, further comprising the use of a non-powder material in the insert. [19] Method according to claim 17, wherein the fitting comprises producing the insert with connected segments having different powder metal compositions. [20] Method according to claim 17, wherein the adjustment comprises varying the composition parameters of the powder metal material continuously from the apex to the lower part.

Images