METHODS OF INCREASING THE VOLUME OF A PERFORATION TUNNEL USING A SHAPED CHARGE

Abstract

A method of increasing the volume of a perforation tunnel in a subterranean formation comprises: positioning a shaped charge in a well, wherein the shaped charge comprises a main explosive load, wherein the main explosive load comprises a substance, wherein the substance is capable of increasing the volume of the perforation tunnel whereas a substantially identical shaped charge without the substance is not capable of increasing the volume of the perforation tunnel.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to PCT Application No. PCT/US12/57494, filed on Sep. 27, 2012.

TECHNICAL FIELD

The present invention relates to an improved shaped charge for use in perforating a subterranean formation. Specifically, the shaped charge includes a main explosive load, which includes a substance that is capable of increasing the volume of the perforation tunnel. The increase in volume can be achieved via an increase in the heat of explosion of the explosive load. The increase in heat of the explosion can be caused by the substance.

SUMMARY

According to an embodiment, a method of increasing the volume of a perforation tunnel in a subterranean formation comprises: positioning a shaped charge in a well, wherein the shaped charge comprises a main explosive load, wherein the main explosive load comprises a substance, wherein the substance is capable of increasing the volume of the perforation tunnel whereas a substantially identical shaped charge without the substance is not capable of increasing the volume of the perforation tunnel.

BRIEF DESCRIPTION OF THE FIGURES

The features and advantages of certain embodiments will be more readily appreciated when considered in conjunction with the accompanying figures. The figures are not to be construed as limiting any of the preferred embodiments.

FIG. 1 depicts a wellbore comprising a shaped charge.

FIG. 2 depicts the shaped charge.

FIG. 3 depicts a perforation tunnel of FIG. 1.

DETAILED DESCRIPTION

As used herein, the words “comprise,” “have,” “include,” and all grammatical variations thereof are each intended to have an open, non-limiting meaning that does not exclude additional elements or steps.

As used herein, the word “substance” means elements, compositions or mixtures having a definite composition and properties. A substance is intended to include, for example, pure elements, alloys, metals, polymers, compounds, mixtures, and combinations thereof. No compound, mixture, or other material is intended to be excluded by the use of the word “substance.”

Shaped charges are used in a variety of applications, such as military and non-military applications. In non-military applications, shaped charges are used: in the demolition of buildings and structures; for cutting through metal piles, columns and beams; for boring holes; and in steelmaking, quarrying, breaking up ice, breaking log jams, felling trees, and drilling post holes. Another common non-military application is the oil and gas industry.

Oil and gas hydrocarbons are naturally occurring in some subterranean formations. A subterranean formation containing oil or gas is sometimes referred to as a reservoir. A reservoir may be located under land or off shore. Reservoirs are typically located in the range of a few hundred feet (shallow reservoirs) to a few tens of thousands of feet (ultra-deep reservoirs). In order to produce oil or gas, a wellbore is drilled into a reservoir or adjacent to a reservoir.

A well can include, without limitation, an oil, gas, or water production well, or an injection well. As used herein, a “well” includes at least one wellbore. A wellbore can include vertical, inclined, and horizontal portions, and it can be straight, curved, or branched. As used herein, the term “wellbore” includes any cased, and any uncased, open-hole portion of the wellbore. A near-wellbore region is the subterranean material and rock of the subterranean formation surrounding the wellbore. As used herein, a “well” also includes the near-wellbore region. The near-wellbore region is generally considered to be the region within approximately 100 feet of the wellbore. As used herein, “into a well” means and includes into any portion of the well, including into the wellbore or into the near-wellbore region via the wellbore.

A portion of a wellbore may be an open hole or cased hole. In an open-hole wellbore portion, a tubing string may be placed into the wellbore. The tubing string allows fluids to be introduced into or flowed from a remote portion of the wellbore. In a cased-hole wellbore portion, a casing is placed into the wellbore that can also contain a tubing string. A wellbore can contain an annulus. Examples of an annulus include, but are not limited to: the space between the wellbore and the outside of a tubing string in an open-hole wellbore; the space between the wellbore and the outside of a casing in a cased-hole wellbore; and the space between the inside of a casing and the outside of a tubing string in a cased-hole wellbore.

Stimulation techniques can be used to help increase or restore oil, gas, or water production of a well. One example of a stimulation technique is a perforation of a well by using shaped charges. The shaped charges can be detonated, thereby creating a void that extends into the formation. The void is called a perforation tunnel. The perforation tunnel increases the permeability of the formation. Permeability refers to how easily fluids flow through a material. This increase in permeability means that fluids will flow more easily into or from the wellbore; thereby increasing the overall production of the well and recovery over time. The perforation tunnels may also allow fracturing fluids to access the formation more easily.

In hydraulic fracturing, a fracturing fluid is pumped at a sufficiently high flow rate and high pressure through the wellbore and into the near wellbore region to create or enhance a fracture in the subterranean formation. Creating a fracture means making a new fracture in the formation. Enhancing a fracture means enlarging a pre-existing fracture or fissure in the formation. A frac pump is used to pump the fracturing fluid into the wellbore and formation at high rates and pressures, for example, at a flow rate in excess of 10 barrels per minute (4,200 U.S. gallons per minute) at a pressure in excess of 5,000 pounds per square inch (“psi”). The pressurized fluid enters the wellbore and formation, through the perforation tunnels. The pressure that is created causes the formation to fracture or crack beyond the perforation tunnels. The fractures create new channels in the formation which may increase the extraction rate of a well.

Perforation tunnels are often created with the use of shaped charges. A shaped charge generally includes a conically-shaped charge case, a solid explosive load, a liner, a central booster, array of boosters, or detonation wave guide, and a hollow cavity forming the shaped charge. If the hollow cavity is lined with a thin layer of metal, plastic, ceramic, or similar materials, the liner forms a jet when the explosive charge is detonated. Upon initiation, a spherical wave propagates outward from the point of initiation in the basic case of a single point initiated charge, initiated along the axis of symmetry. This high pressure wave moves at a very high velocity, typically around 8 kilometers per second (km/s). As the detonation wave engulfs the lined cavity, the liner material is accelerated under the high detonation pressure, collapsing the liner. During this process, for a typical conical liner, the liner material is driven to very violent distortions over very short time intervals (microseconds) at strain rates of 104 to 107/s. Maximum strains greater than 10 can be readily achieved since superimposed on the deformation are very large hydrostatic pressures (peak pressures of approximately 200 gigapascals “GPa” (30 million pounds force per square inch “psi”), decaying to an average of approximately 20 GPa). The collapse of the liner material on the centerline forces a portion of the liner to flow in the form of a jet where the jet tip velocity can travel in excess of 10 km/s. The conical liner collapses progressively from apex to base under point initiation of the high explosive. A portion of the liner flows into a compact slug (sometimes called a carrot), which is the large massive portion at the rear of the jet.

Liners can be made from a variety of materials, including various metals and glass. Common metals include copper, aluminum, tungsten, tantalum, depleted uranium, lead, tin, cadmium, cobalt, magnesium, titanium, zinc, zirconium, molybdenum, beryllium, nickel, silver, gold, platinum, and pseudo-alloys of tungsten filler and copper binder. The selection of the material depends on many factors including economic drivers as well as performance requirements. For example, a copper and lead powdered matrix pressed into a final geometric form has been found to work well for the oil and gas industry, historically with higher performance embodiments comprising increasing amounts of tungsten powder within the metal matrix.

Shaped charges are generally positioned in the wellbore and can be included in a perforating gun. The perforating gun can be used to hold the charges. The perforating gun may be placed inside a casing and is lowered into the well on either tubing or a wire line until it is at the desired location within the well. The perforating gun assembly generally includes a charge holder that holds the shaped charges, a detonation cord that links each charge located in the charge holder, and a detonator. When the charges are detonated, particles are expelled, forming a high-velocity jet that creates a pressure wave that exerts pressure on the formation and possibly the casing for a cased-hole portion. The detonation creates the perforation tunnel by forcing material radially away from the jet axis.

It has been discovered that the volume of a perforation tunnel can be increased by using a shaped charge including a substance within the main explosive load. The substance increases the overall heat produced by the detonation or explosion of the charge. The increased heat of explosion will result in an increase in volume of the perforation tunnel.

According to an embodiment, a method of increasing the volume of a perforation tunnel in a subterranean formation comprises: positioning a shaped charge in a well, wherein the shaped charge comprises a main explosive load, wherein the main explosive load comprises a substance, wherein the substance is capable of increasing the volume of the perforation tunnel whereas a substantially identical shaped charge without the substance is not capable of increasing the volume of the perforation tunnel.

Any discussion of the embodiments regarding the shaped charge is intended to apply to all of the method embodiments. Any discussion of a particular component of an embodiment (e.g., a shaped charge or a substance) is meant to include the singular form of the component and also the plural form of the component, without the need to continually refer to the component in both the singular and plural form throughout. For example, if a discussion involves “the shaped charge 100,” it is to be understood that the discussion pertains to one shaped charge (singular) and two or more shaped charges (plural).

Turning to the Figures, FIG. 1 depicts a well system 10 containing multiple shaped charges 100 located within multiple zones of the well system. The well system 10 can include at least one wellbore 11. The wellbore 11 can penetrate a subterranean formation 20. The subterranean formation 20 can be a portion of a reservoir or adjacent to a reservoir. The wellbore 11 can have a generally vertical cased or uncased section 14 extending downwardly from a casing 15, as well as a generally horizontal cased or uncased section extending through the subterranean formation 20. The wellbore 11 can include only a generally vertical wellbore section or can include only a generally horizontal wellbore section.

A tubing string 24 (such as a stimulation tubing string or coiled tubing) can be installed in the wellbore 11. The well system 10 can comprise at least a first zone 16 and a second zone 17. The well system 10 can also include more than two zones, for example, the well system 10 can further include a third zone 18, a fourth zone 19, and so on. The methods include the step of positioning a shaped charge 100 in a well. More than one shaped charge 100 can be positioned in the well. According to an embodiment, a first shaped charge can be positioned within the first zone 16, a second shaped charge can be positioned within the second zone 17, and so on. It is to be understood that more than one shaped charge can be positioned within a given zone (e.g., the first zone or second zone). According to an embodiment, the well system 10 includes anywhere from 2 to hundreds or thousands of zones. The zones can be isolated from one another in a variety of ways known to those skilled in the art. For example, the zones can be isolated via multiple packers 26. The packers 26 can seal off an annulus located between the outside of the tubing string 24 and the wall of wellbore 11.

It should be noted that the well system 10 is illustrated in the drawings and is described herein as merely one example of a wide variety of well systems in which the principles of this disclosure can be utilized. It should be clearly understood that the principles of this disclosure are not limited to any of the details of the well system 10, or components thereof, depicted in the drawings or described herein. Furthermore, the well system 10 can include other components not depicted in the drawing. For example, the well system 10 can further include a well screen. By way of another example, cement may be used instead of packers 26 to isolate different zones. Cement may also be used in addition to packers 26.

The well system 10 does not need to include a packer 26. Also, it is not necessary for one well screen and one shaped charge 100 to be positioned between each adjacent pair of the packers 26. It is also not necessary for a single shaped charge 100 to be used in conjunction with a single well screen. Any number, arrangement and/or combination of these components may be used.

The step of positioning can comprise inserting the shaped charge 100 into the well. The shaped charge 100 can be positioned in the well at a desired location. According to an embodiment, the desired location is the location at which the perforation tunnel 22 is to be created. The shaped charge 100 can be included in a carrier (not shown). More than one shaped charge 100 can be included in the carrier. The carrier can be any carrier capable of holding the shaped charge 100, for example, the carrier can be a perforating gun. The step of positioning can further comprise inserting the carrier into the well. The methods can further include the step of inserting the shaped charge 100 into the carrier, wherein the step of inserting is performed prior to the step of positioning.

As can be seen in FIG. 2, the shaped charge 100 includes a main explosive load 102. The shaped charge 100 can further include a charge case 101, wherein the charge case 101 is positioned adjacent to the main explosive load 102. The charge case 101 can comprise a metal or metal alloy. As used herein, the term “metal alloy” means a mixture of two or more elements, wherein at least one of the elements is a metal. The other element(s) can be a non-metal or a different metal. An example of a metal and non-metal alloy is steel, comprising the metal element iron and the non-metal element carbon. An example of a metal and metal alloy is bronze, comprising the metallic elements copper and tin. The metal or metal alloy of the charge case 101 can be selected from the group consisting of aluminum, zinc, magnesium, titanium, tantalum, and combinations thereof.

The shaped charge 100 can further comprise a liner 103, wherein the liner 103 is positioned adjacent to the main explosive load 102. As can be seen in FIG. 2, the shaped charge 100 can include a liner 103, the main explosive load 102, and a charge case 101, wherein the liner 103 is positioned adjacent to the main explosive load 102 and the charge case 101 is positioned adjacent to the other side of the main explosive load 102. The liner 103 can be made from a variety of materials, including various metals and glass. Common metals include copper, aluminum, tungsten, tantalum, depleted uranium, lead, tin, cadmium, cobalt, magnesium, titanium, zinc, zirconium, molybdenum, beryllium, nickel, silver, gold, platinum, and pseudo-alloys of tungsten filler and copper binder. The liner 103 can have a thickness of at least 0.025 inches (in). According to another embodiment, the liner 103 has a thickness in the range of about 0.025 to about 0.250 in, preferably of about 0.050 to about 0.100 in.

The shaped charge 100 can further comprise a central booster, array of boosters, or detonation wave guide (shown in FIG. 2 as a central booster 106). According to an embodiment, the central booster, array of boosters, or detonation wave guide is capable of detonating the main explosive load 102. Detonation means a supersonic exothermic front accelerating through a medium that eventually drives a shock front or wave that propagates directly in front of the explosive load. The shaped charge 100 can further include a seal disc 105 and a detonation cord 104. According to an embodiment, the detonation cord 104 is capable of initiating the central booster, array of boosters, detonation wave guide, or the main explosive load 102. If more than one shaped charge 100 is positioned in the well, then the detonation cord 104 can be connected to and link two or more of the shaped charges 100 together. The detonation cord 104 can be part of a carrier (not shown).

The shaped charge 100 comprises the main explosive load 102. According to an embodiment, the main explosive load 102 comprises an explosive material. The explosive material can be selected from commercially-available materials. For example, the explosive material can be selected from the group consisting of [3-Nitrooxy-2,2-bis(nitrooxymethyl)propyl]nitrate “PETN”; 1,3,5-Trinitroperhydro-1,3,5-triazine “RDX”; Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine “HMX”; 1,3,5-Trinitro-2-[2-(2,4,6-trinitrophenyl)ethenyl]benzene “HNS”; 2,6-bis,bis(picrylamino)-3,5-dinitropyridine “PYX”; 1,3,5-trinitro-2,4,6-tripicrylbenzene “BRX”; 2,2′,2″,4,4′,4″,6,6′,6″-nonanitro-m-terphenyl “NONA”; and combinations thereof. According to an embodiment, the main explosive load 102 further comprises a de-sensitizing material. The de-sensitizing material can be capable of binding the main explosive load 102 together. The de-sensitizing material can also help the main explosive load 102 retain its shape. The de-sensitizing material can be selected from the group consisting of a wax, graphite, plastics, thermoplastics, fluoropolymers (e.g., polytetrafluoroethylene), other non-energetic (inert) binders, and combinations thereof.

The substance is capable of increasing the volume of the perforation tunnel 22; whereas, a substantially identical shaped charge without the substance is not capable of increasing the volume of the perforation tunnel. As used herein, the phrase “substantially identical” means the device contains the same components, materials, concentrations of materials, etc. with the exception of the component or material specifically excluded. As can be seen in FIG. 3, the perforation tunnel 22 can be, but is not limited to being, conical in shape. The increase in volume can be an increase in at least one dimension of the perforation tunnel. According to an embodiment, the increase in the at least one dimension can be an increase in the diameter of the base of the perforation tunnel b, the length of the perforation tunnel l, an increase in both the diameter of the base b and the length l, or an increase in a diameter at any interval along the length l. The increase in the volume can vary depending on the specifics of the oil or gas operation. The increase in the volume can be a desired value.

According to an embodiment, the substance is capable of increasing the volume of the perforation tunnel 22 via an increase in the amount of heat of explosion of the main explosive load 102 (i.e., the amount of heat produced during detonation of the main explosive load). The generation of heat in large quantities accompanies most explosive chemical reactions. It is the rapid liberation of heat that causes the gaseous products of most explosive reactions to expand and generate high pressures. This rapid generation of high pressures of the released gas constitutes the explosion. The strength, or potential, of an explosive is the total work that can be performed by the gas resulting from its explosion, when expanded adiabatically from its original volume, until its pressure is reduced to atmospheric pressure and its temperature to 15° C. The potential is therefore the total quantity of heat given off at constant volume when expressed in equivalent work units and is a measure of the strength of the explosive. Each product and reactant making up the explosive load will have a specific heat of formation. The standard heat of formation of a compound is the change of enthalpy that accompanies the formation of 1 mole of the compound from its elements, with all substances being in their standard states. The heat released by the explosive material at a constant pressure and 25° C. can be calculated as follows:

HEX=ΔU=|U_prod1−U_react1|+|U_prod2−U_react2| . . . ,

where HEX refers to the heat of explosion in units of calories per gram (cal/g); ΔU is the change in energy at a constant volume for the calorimetric reaction; and U_prod and U_react are the internal energies of the products and reactants (1, 2, and so on), respectively, at room temperature (i.e., 25° C. (298.15 K)). The heat released can be referred to as the “heat of explosion.” With an increase in HEX, the explosive load has an increased ability to do work. This increased ability to do work means that the overall volume of the perforation tunnel can be increased compared to an explosive load without the increase in HEX. According to an embodiment, the increase in the heat of explosion is predetermined. The predetermined heat of explosion can, in part, be calculated based on the desired increase in the volume of the perforation tunnel 22, but may also be derived from experimental results.

According to an embodiment, the substance is any substance that is capable of increasing the overall heat of explosion of the main explosive load 102, thereby resulting in an overall increase in the ability to perform work, thereby increasing the perforation tunnel geometry. The main explosive load 102 can also comprise more than one substance. The substance can be selected from the group consisting of metals, metal alloys, plastics, thermoplastics, fluoropolymers (e.g., polytetrafluoroethylene), and combinations thereof. The metal or metal alloy can be selected from (but not limited to) the group consisting of aluminum, zinc, magnesium, titanium, tantalum, and combinations thereof. The quantity of the heat of explosion and overall higher work energy can vary and will depend on the heat for formation of the specific substance(s) chosen. For example, the heat of formation of aluminum oxide (Al₂O) is 163 kilojoules per mole (kJ/mol) and the heat of formation of aluminum III oxide (Al₂O₃) is 1,590 kJ/mol. According to an embodiment, the one or more substances are chosen such that a desired heat of explosion is achieved.

The quantity of the heat of explosion can also depend on the concentration of the one or more substances. Generally, the greater the concentration of the substance, the greater the heat of explosion. According to an embodiment, the concentration of the one or more substances is selected such that the desired heat of explosion is achieved. According to another embodiment, the concentration of the one or more substances is selected such that the desired increase in volume of the perforation tunnel is achieved. According to yet another embodiment, the substance is in a concentration of at least 0.05% by weight of the main explosive load 102. According to yet another embodiment, the substance is in a concentration in the range of about 0.05% to about 40%, preferably about 1% to about 25%, by weight of the main explosive load 102.

The heat of explosion can be limited by the oxygen balance of the explosive. Oxygen balance (OB or OB %) indicates the degree to which an explosive can be oxidized. If an explosive molecule contains just enough oxygen to form carbon dioxide from carbon, water from hydrogen molecules, all of its sulfur dioxide from sulfur, and all metal oxides from metals with no excess molecules, then the explosive has a zero oxygen balance. An explosive has a positive oxygen balance if the explosive contains more oxygen than needed, and an explosive has a negative oxygen balance if the explosive contains less oxygen than needed. If the explosive has a negative oxygen balance, then the combustion of the explosive molecules will be incomplete, and large amounts of toxic gases such as carbon monoxide will be present. Generally, when a positive or zero OB is present, the heat of explosion will be the greatest; whereas, the heat of explosion will be less when a negative OB is present. According to an embodiment, the main explosive load 102 has a positive or zero OB. According to another embodiment, a sufficient amount of oxygen (O₂) is available to cause complete combustion of the main explosive load 102. The available O₂ can come from the substance, part of another material (e.g., the booster), and/or the area surrounding the shaped charge.

The substance can be selected such that at least a sufficient amount of oxygen is available in order to achieve complete combustion of the main explosive load 102. The substance can also be selected such that at least a sufficient amount of oxygen is available in order to achieve the predetermined heat of explosion. The substance can also be selected such that at least a sufficient amount of oxygen is available in order to achieve the desired increase in volume of the perforation tunnel 22. The concentration of the substance can also be selected such that at least a sufficient amount of oxygen is available in order to achieve complete combustion of the main explosive load; alternatively, such that at least a sufficient amount of oxygen is available in order to achieve the predetermined heat of explosion; alternatively, such that the desired increase in volume of the perforation tunnel is achieved. By way of example, Al₂O₃ can provide more available oxygen compared to Al₂O. The substance and/or the concentration of the substance can also be selected based on the quantity of available oxygen present in the area surrounding the positioned shaped charge.

The substance can also form available oxygen by reacting with other unoxidized elements or compounds present in the system. The substance can also increase the heat of explosion by reacting with other unoxidized elements or compounds present in the system. By way of example, if the substance is Al₂O and a negative OB is present, then the formation of Al₂O₃ via a reaction of the Al₂O and other unoxidized compounds or elements can occur. The formation of Al₂O₃ is a highly exothermic chemical reaction and can increase the overall heat of explosion.

The methods can further comprise the step of detonating the main explosive load 102, wherein the step of detonating is performed after the step of positioning. The step of detonating can comprise causing initiation of the main explosive load 102. The initiation of the main explosive load 102 can include initiating the booster 106, booster array, or detonation wave guide. According to an embodiment, the detonation of the main explosive load 102, and the jet produced by the liner material 103, creates the resulting perforation tunnel 22. More than one main explosive load 102 can be detonated. As can be seen in FIG. 1, a first main explosive load 102 located in the first zone 16 can be detonated; thereby creating a first perforation tunnel 22, a second main explosive load shown located in the third zone 18 can be detonated; thereby creating a second perforation tunnel, and so on. Of course more than one main explosive load can be detonated within a given zone. Moreover, not every zone need include a shaped charge and the exact zones that contain a shaped charge and the total number of shaped charges positioned within those zones can vary depending on the specifics of the particular oil or gas operation.

The methods can further comprise the step of fracturing at least a portion of the subterranean formation 20, wherein the step of fracturing is performed after the step of positioning or after the step of detonating. The step of fracturing can include placing a fracturing fluid into at least one of the perforation tunnels 22. The methods can further include the step of performing an acidizing treatment in at least a portion of the subterranean formation 20, wherein the step of performing an acidizing treatment is performed after the step of positioning or after the step of detonating. The step of performing an acidizing treatment can include introducing an acidizing fluid into at least one of the perforation tunnels 22.

Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention 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 embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods also can “consist essentially of” or “consist of” the various components and steps. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. 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. If there is any conflict in the usages of a word or term in this specification and one or more patent(s) or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.

Claims

1. A method of increasing the volume of a perforation tunnel in a subterranean formation comprising:

positioning a shaped charge in a well, wherein the shaped charge comprises a main explosive load, wherein the main explosive load comprises a substance, wherein the substance is capable of increasing the volume of the perforation tunnel whereas a substantially identical shaped charge without the substance is not capable of increasing the volume of the perforation tunnel.

2. The method according to claim 1, wherein the step of positioning comprises inserting the shaped charge into the well.

3. The method according to claim 1, wherein the main explosive load comprises an explosive material.

4. The method according to claim 3, wherein the explosive material is selected from the group consisting of: [3-Nitrooxy-2,2-bis(nitrooxymethyl)propyl]nitrate “PETN”; 1,3,5-Trinitroperhydro-1,3,5-triazine “RDX”; Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine “HMX”; 1,3,5-Trinitro-2-[2-(2,4,6-trinitrophenyl)ethenyl]benzene “HNS”; 2,6-bis,bis(picrylamino)-3,5-dinitropyridine “PYX”; 1,3,5-trinitro-2,4,6-tripicrylbenzene “BRX”; 2,2′,2″,4,4′,4″,6,6′,6″-nonanitro-m-terphenyl “NONA”; and combinations thereof.

5. The method according to claim 1, wherein the increase in volume of the perforation tunnel is an increase in at least one dimension of the perforation tunnel.

6. The method according to claim 1, wherein the substance is capable of increasing the volume of the perforation tunnel via an increase in the amount of heat of explosion of the main explosive load.

7. The method according to claim 6, wherein the substance is any substance that is capable of increasing the heat of explosion of the main explosive load.

8. The method according to claim 6, wherein the increase in the heat of explosion is predetermined.

9. The method according to claim 8, wherein the concentration of the substance is selected such that the predetermined heat of explosion is achieved.

10. The method according to claim 8, wherein the substance is selected such that a predetermined heat of explosion is achieved.

11. The method according to claim 1, wherein the main explosive load comprises more than one substance.

12. The method according to claim 1, wherein the substance is selected from the group consisting of metals, metal alloys, plastics, thermoplastics, fluoropolymers, and combinations thereof.

13. The method according to claim 10, wherein the metal or metal alloy is selected from the group consisting of aluminum, zinc, magnesium, titanium, tantalum, and combinations thereof.

14. The method according to claim 1, wherein the concentration of the substance is selected such that a desired increase in volume of the perforation tunnel is achieved.

15. The method according to claim 1, wherein the substance is in a concentration in the range of about 0.05% to about 40% by weight of the main explosive load.

16. The method according to claim 1, wherein the main explosive load has a positive or zero oxygen balance.

17. The method according to claim 1, wherein a sufficient amount of oxygen is available to cause complete combustion of the main explosive load.

18. The method according to claim 1, wherein the substance is selected such that at least a sufficient amount of oxygen is available in order to achieve a desired increase in volume of the perforation tunnel.

19. The method according to claim 1, wherein the concentration of the substance is selected such that at least a sufficient amount of oxygen is available in order to achieve a desired increase in volume of the perforation tunnel.

20. The method according to claim 1, further comprising the step of detonating the main explosive load, wherein the step of detonating is performed after the step of positioning.