WO2001004452A1 - Charge formee encapsulee pour perforation de puits - Google Patents

Charge formee encapsulee pour perforation de puits Download PDF

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Publication number
WO2001004452A1
WO2001004452A1 PCT/US2000/018486 US0018486W WO0104452A1 WO 2001004452 A1 WO2001004452 A1 WO 2001004452A1 US 0018486 W US0018486 W US 0018486W WO 0104452 A1 WO0104452 A1 WO 0104452A1
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WO
WIPO (PCT)
Prior art keywords
shaped charge
cap
case
encapsulated
cap member
Prior art date
Application number
PCT/US2000/018486
Other languages
English (en)
Inventor
John Aitken
Jorge E. Lopez De Cardenas
Original Assignee
Schlumberger Technology Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Schlumberger Technology Corporation filed Critical Schlumberger Technology Corporation
Priority to AU62061/00A priority Critical patent/AU6206100A/en
Publication of WO2001004452A1 publication Critical patent/WO2001004452A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B3/00—Blasting cartridges, i.e. case and explosive
    • F42B3/08—Blasting cartridges, i.e. case and explosive with cavities in the charge, e.g. hollow-charge blasting cartridges
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/11—Perforators; Permeators
    • E21B43/116—Gun or shaped-charge perforators
    • E21B43/117—Shaped-charge perforators

Definitions

  • This invention relates generally to well perforating guns having a plurality of encapsulated shaped explosive charges which are run into a well casing or well bore liner to a desired depth for communication with one or more petroleum production zones of the surrounding earth formation and fired to perforate the well casing to thus admit petroleum products, such as natural gas, crude oil and water into the well casing for production. More particularly, the present invention is directed to the provision of a novel encapsulated shaped charge which, when fired, causes the cap thereof to be fractured into a multiplicity of small pieces or a granular form which will not agglomerate with other well constituents and will not tend to create an obstruction within the well casing or the production tubing, control valves and other components of the well.
  • the present invention is directed to an encapsulated shaped explosive charge having a casing and closure cap that have the capability of releasing gas pressure in the event excessive heat is encountered, so that the potential for unintended heat induced detonation of the shaped charge during its storage, handling or transportation is significantly minimized.
  • Encapsulated shaped charges mounted in perforating gun devices are used extensively to perforate oil and gas wells by passing the perforating guns through the production tubing of the well and positioning the perforating gun at a suitable depth and location within the well casing or well bore liner matching the depth or location of one or more production zones intersected by the well bore that has been drilled.
  • the well casing or well bore liner will have been cemented in place so that the annulus between the wellbore in the earth formation and the external surface of the well casing is filled with hardened cement.
  • perforating guns may be used to create perforations in uncased holes (or open holes), wherein the well bore does not include a casing or liner.
  • the encapsulated explosive charges of typical perforating guns are quite small in dimension so that the perforating gun with all of its charges can be passed through standard production tubing.
  • the perforating charges of a typical perforating gun are phased at differing angles so that the perforations caused by individual shaped charges radiate in differing directions from the gun structure or strip and thus establish perforations in the well casing, cement and formation at differing angular orientations, such as indicated in U. S. Patents Nos. 4.951,744 of Rytlewski, 5,095,999 of Markel and 5,544,71 1 of Aitken, et al.
  • Three tubing perforating guns are small in diameter relative to the well casing, limiting the explosive powder load that is available for explosive preparation; consequently the penetration and phasing of the perforated holes as well as the amount and type of debris left in the well by the detonating perforating gun are important considerations.
  • Small diameter "through tubing" perforating guns utilizing encapsulated explosive charges are typical of two general types: In one type of perforating gun, the encapsulated explosive charges are linked together as a chain leaving as debris in the well all of the metallic material in the perforating gun. Link-type perforating guns configured in a spiral firing pattern lose efficiency on the particular explosive charge shots that must fire across large diameter fluid filled casings before penetrating the formation surrounding the well casing.
  • the second general type of "through tubing" perforating gun utilizes in-line firing charges that are mounted on explosive resistant steel carrier strips having the capability of withstanding the explosive detonation of the charges and remaining intact so that the carrier strips may be retrieved after casing perforation activity has been accomplished. For the reason that the steel carrier strips are retrieved after firing of the perforating gun, thus only the debris of the charge cases will remain in the well after the perforating gun has been fired and retrieved.
  • In-line strips are positioned in the well casing so that all of the charges fire with zero clearance directly into the casing, maximizing the diameter of the perforated holes in the casing and penetration of the explosive energy into the formation, yielding in general better penetration and possibly higher productivity than wells perforated with spiral phased through tubing type perforating guns. More recently, a through tubing strip gun has been developed. as indicated by US Patent #5095999 of Markel and Patent #554471 1 of Aitken. These patents disclose an explosive resistant carrier strip which is configured to orient explosive charges so that the penetration jets of the charges are directed 45 degrees apart.
  • each of the explosive charges is oriented at plus or minus 22.5 degrees from the line of contact.
  • This type of two-phased through tubing perforating gun establishes a 90 degree shot pattern which offers some advantage over the single phased in-line configuration that is normal with most strip guns.
  • the explosive charges of a typical perforating gun are quite small to enable them, when assembled with the recoverable strip of the strip gun to pass through a conventional production tubing string so that the perforating gun can be positioned in contact with the well casing, or very close thereto, at a well depth that is below a packer sealing the production tubing string to the well casing.
  • the small explosive charges however are packed tightly with powerful loads of explosive material which is shaped to define a concave, typically somewhat conical recess therein. As the explosive charge is ignited, the conical recess configuration of the explosive charge causes the development of a very concentrated and specifically oriented explosive jet with sufficient explosive force to penetrate the well casing and the cement annulus surrounding the well casing and also penetrate well into the formation to be produced.
  • the typically steel or other metallic material of the charge cases which are in close contact with the explosive material will be fragmented into small chips or pieces which gravitate to the bottom of the well below all prospective zones of production.
  • the caps may remain essentially intact or may be fractured into fairly large sections as the result of perforation gun detonation. These caps or cap sections may agglomerate with other debris within the well, creating an obstruction to well production. The presence of these caps or large cap sections within the well may prevent or interfere with future well construction or other well service operations below this point in the well.
  • the multiple shaped charges of a perforating gun typically are defined by a case structure having an internal cavity defining a generally conical shaped receptacle within which the explosive composition is packed.
  • a cap To the case is assembled a cap with assembly being accomplished in the presence of a circular sealing element establishing efficient sealing between the case and the cap.
  • the sealing element is arranged to release internal pressure which might develop within the sealed case responsive to conditions of heat induced out-gassing of the explosive composition or leakage of well gases under pressure into the hollow cavity of the charge. This pressure releasing capability can be important when perforating guns are removed from a well unfired, after having been heated by the elevated temperature of the well at perforation depth.
  • the pressure relieving capability of the seal and pressure relief ring ensures that the internal pressure within the explosive containing cavity is substantially equalized with atmospheric pressure so that there is no tendency for the front cap to be forced from the charge case by pressure differential.
  • the charge case and cap assembly, including the sealing element for sealing the cap to the charge case, are also designed to be non- porous, so that leakage of external well pressure into the hollow, explosive containing cavity of the shaped charge will not occur. This feature minimizes any tendency for the cap to be forcibly ejected from the charge case by excess internal pressure when unfired charges are removed from a well.
  • both the cap and cases of encapsulated shaped charges for well casing perforation have been manufactured from pure alumina ceramic which is highly impermeable, is quite resistant to abrasion and can sustain high well pressures and temperature.
  • the performance of these ceramic encased charges has proven to be significantly lower than steel cased charges.
  • encapsulated shaped charges composed entirely of ceramic material have been determined to be difficult to manufacture and they have been found to be very costly from the standpoint of manufacture.
  • a hermetically sealed, fully expendable shaped perforating charge consisting of a charge case composed of steel or other suitable material which defines an internal chamber.
  • the charge case contains a highly compressed explosive shaped charge that is designed for the development of a small, specifically oriented explosive jet for perforating a well casing upon detonation and penetrating through the well casing, through the cement in the annulus between the well bore and the well casing and also penetrating a desired distance into the formation to be produced.
  • the charge case is closed to well fluids by a cap that is clamped to the charge case by a circular crimp ring.
  • the crimp ring is applied over a thermoplastic pressure release ring member which is encircled about an elastomer sealing element that establishes sealing between the case and cap to exclude well pressure from the internal chamber of the case and cap.
  • the thermoplastic pressure release ring defines at least one and preferably a plurality of vent or bleed slots which permit internal pressure of the chamber being released by the elastomer seal to bleed past the thermal release ring, averting a violent ejection of the front cap should the gun be retrieved from the well unfired.
  • thermoplastic pressure release ring maintains the cap securely to the charge case but will melt, in the event that the gun or charges in transit or storage are subjected to extremely high temperature, such as in the case of a fire, releasing the front cap as the explosive begins to out-gas, permitting release of the gas pressure and permitting burning but avoiding detonation of the explosive composition constituting the shaped charges involved.
  • a low melting metal alloy crimp ring provided with internal pressure relief slots, is crimped about the joint between the charge case and the ceramic front cap, thus securing the ceramic cap to the charge case and activating the elastomeric interference seal sealing the ceramic end cap to the charge case.
  • the melting point of the crimp ring alloy is adjusted to suit the out-gassing temperature of the explosive used in the charge, i.e., approximately 400 degrees F for RDX, approximately 500 degrees F for HNS or PYX commonly used in well perforation shaped charges.
  • the low melting temperature alloy crimp ring will function efficiently to retain the end cap and charge case in sealed assembly under normal use in a well, but in the event of excessive heat, such as in the case of a fire, the crimp ring will be melted and will release the end cap from the charge case and thus permit release of excessive out-gassing pressure, so that the explosive composition will burn but will not detonate.
  • a shaped charge case and cap is employed in assembly to define a sealed shaped charge for well perforation guns.
  • the cap is manufactured with a plurality of fracture grooves which define a geometric fracture pattern. The explosive detonation will cause the cap to fracture along the fracture pattern and will thus cause the resulting cap particles or sections to be sufficiently small that they will not interfere with subsequent well construction or servicing operations.
  • Fig. 1 is a view in plan, with a part thereof broken away and shown in section, illustrating an encapsulated explosive shaped charge which is constructed in accordance with the principles of the present invention and which is designed for use in a perforating gun for perforating the casing or liner of a well;
  • Fig. 2 is a sectional view of the broken away section of Fig. 1 , illustrating the charge case and cap assembly in greater detail;
  • Fig. 3 is a partial sectional view showing the original configuration of the pressure relief ring prior to crimped retention thereof in assembly with the encapsulated shaped charge structure;
  • Fig. 4 is a partial sectional view showing the retained configuration of the pressure release ring and further showing the relationship thereof to the charge case and front cap structures;
  • Fig. 5 is a fragmentary sectional view of the sealing and pressure relief structure of the encapsulated explosive shaped charge of the present invention and showing internal pressure responsive movement of the O-ring seal for relief of excess internal pressure;
  • Fig. 6 is another view in plan, showing an alternative embodiment of the present invention, with a part thereof broken away and shown in section, illustrating an encapsulated explosive shaped charge which is designed for use in a perforating gun for perforating the casing or liner of a well;
  • Fig. 7 is a sectional view showing the crimp ring of the embodiment of Fig. 5, prior to crimping thereof;
  • Fig. 8 is an end view of the crimp ring of Fig. 7;
  • Fig. 9 is a sectional view of the broken away section of Fig. 6, showing the crimped condition of the crimp ring and further showing retention by the crimp ring of a front cap of the explosive shaped charge with vent grooves or slots of the crimp ring associated with a seal ring to permit release of internal pressure due to out-gassing of the explosive composition of the shaped charge;
  • Fig. 10 is a fragmentary sectional view of an alternative embodiment of the charge case and cap structures showing a circular seal groove that is cooperatively defined by circular tapered surfaces of the case and cap;
  • Fig. 1 1 is a fragmentary sectional view of an alternative embodiment of the charge case and cap structures showing a circular seal groove that is defined by a circular recess in the charge case and a planar surface of the cap;
  • Fig. 12 is a plan view of a cap for a shaped charge case and cap assembly, wherein the cap defines a plurality of fracture grooves for ensuring fracture of the cap into a multiplicity of small pieces or sections responsive to the force of explosive detonation;
  • Fig. 13 is a side elevational view of the cap structure of Fig. 12;
  • Fig. 14 is a plan view of a shaped charge cap, similar to that of Fig. 12 and representing an alternative embodiment showing an additional optional fracture groove defined in the central portion of the cap.
  • an encapsulated explosive shaped charge for casing perforation of wells which is constructed in accordance with the principles of the present invention ,is shown generally at 10.
  • the encapsulated explosive shaped charge 10 is defined by a charge case 12 which is preferably composed of steel, but which may be composed of any other suitable metal or non-metal material having sufficient structural integrity for the intended purpose.
  • the rear end 14 of the charge case 12 defines a rear projection 16 having an aperture 18 through which is threaded a length of explosive primacord which is selectively fired, such as by an electrically initiated detonating cap, not shown, and which initiates the explosive shaped charges within the encapsulated explosive shaped charge 10 and also initiates each of the other encapsulated explosive shaped charges of the perforating gun.
  • the projection 16 may define a slot or any other suitable recess for receiving a length of explosive initiating primacord.
  • the charge case 12 defines wall structure 20 which is of generally circular configuration at the front end 22 and which defines an essentially funnel shaped internal wall surface 24 that may be of curved configuration or of conical configuration so as to define an internal charge case receptacle 26 of a desired concave configuration for the shaped explosive charge that is located therein.
  • the shaped explosive charge may be composed of any of a number of suitable explosive compositions that are considered suitable for use in well casing perforating guns. For example, explosive compositions such as RDX, HNS, PYX, HMX and HTX are commonly used in well perforation shaped charges.
  • shaped is intended to mean any suitable explosive composition which is concave shaped to define an explosive jet focusing capability so that detonation of the explosive composition will generate a, concentrated and specifically oriented explosive jet having the capability for penetrating the steel material of a well casing and for penetrating through the cement annulus about the well casing and well into the formation to be produced.
  • the configuration of the wall structure of the charge case also assists the explosive composition in focusing the energy of the explosive charge so as to develop a well defined and specifically oriented explosive jet.
  • the front end 22 of the charge case 12 defines a generally circular and preferably planar surface 28 which functions as a sealing surface and which also functions as a structural support surface for a front end cap member 30.
  • the front end cap 30 is preferably composed of ceramic material which, upon detonation of the shaped charge, will be broken into a multiplicity of small pieces or particles that will fall to the bottom of the wellbore and will not represent a hazard to various well servicing operations that are subsequently carried out.
  • the ceramic material of the front end cap will essentially be rendered to granular form not unlike sand by detonation of the explosive composition, while the steel charge case will be fractured by the explosive detonation into a large number of small case sections that will not represent an obstruction within the wellbore.
  • a generally circular region 32 of the end cap 30 is normally disposed in face to face engagement with the surface 28 as shown in Fig. 1 and in greater detail in Fig. 2.
  • the front cap 30 is provided with a generally circular seal recess 34 which is defined by a generally cylindrical recess surface 36 and a circular planar recess surface 38.
  • the planar end surface 28 also defines a surface of the seal recess 34.
  • a generally circular sealing element 40 composed of elastomeric sealing material is located within the seal recess and is "activated", i.e., compressed by the end cap to effect interference sealing between the charge case and the end cap.
  • the elastomeric sealing element 40 is preferably in the form of an O-ring seal and is of a greater cross- sectional dimension as compared with the spacing of the planar sealing surfaces 28 and 38.
  • O-ring sealing element will be physically deformed from a circular cross-sectional configuration to the oval cross-sectional configuration shown in Fig. 2, thus causing its compressive sealing engagement with the opposed planar surfaces 28 and 38.
  • seal recess 34 is open at its outer periphery.
  • the cap member 30 is sealed with respect to the circular front end 22 of the charge case 12 it may become necessary to vent or release any excess pressure that might build up within the internal charge case receptacle 26.
  • the surrounding formation can be at a substantially elevated temperature that the explosive composition of the internal shaped charge within the charge receptacle 26 may begin to liberate gas, a condition known as out-gassing.
  • gas pressure can build up quickly.
  • an increase in the internal pressure of the charge case receptacle can also occur if wellbore gases migrate into the receptacle while the perforating gun is downhole. Additionally, should well fluid, particularly natural gas penetrate into the internal cavity of the charge, such as by penetrating through porous wall structure of the charge case or cap, the pressure within the charge case can be significantly elevated. If the perforating gun is then removed from the well in its unfired condition, the external pressure will be diminished from well pressure at depth to atmospheric pressure. When either of these conditions occurs, the internal pressure of the charge case receptacle can cause the front cap of the charge to be forcibly ejected, i.e., blown away, thus presenting a potentially dangerous situation.
  • the pressure seal between the metal charge case and the ceramic cap may also be designed according to the alternative embodiments of Figs. 10 and 1 1.
  • the charge case 21 defines a circular tapered surface 23 which cooperates with a circular oppositely tapered surface 25 of a ceramic charge cap 27 to define a circular seal groove at the juncture of planar surfaces 29 and 31 of the charge case and ceramic cap, respectively.
  • the metal charge case 33 defines a circular seal recess 35 which contains a compression type elastomer O-ring seal 37.
  • the ceramic cap 39 defines a circular planar surface 41 which cooperates with the circular seal recess surfaces of the seal recess 35 to form a circular seal groove containing the sealing element 37.
  • a pressure bleeding arrangement is defined by a thermoplastic, yieldable pressure release ring 42 which, when viewed in cross-section as shown in Fig. 2, includes a generally cylindrical intermediate section 44, an angulated or tapered front cap retainer section 45 and a generally frusto-conical or tapered rear section 46.
  • the angulated or tapered front cap retainer section 45 engages a tapered front end surface 47 of the front end cap 30 as shown in Fig. 4 and assists the crimp ring in retention of the front end cap against internal charge pressure.
  • the generally cylindrical intermediate section 44 of the pressure release ring 42 defines an inner cylindrical surface section 48 which, when the yieldable pressure release ring 42 is in assembly with the charge case and front cap member, is disposed in engagement with a generally cylindrical outer peripheral surface 50 of the front cap 30.
  • the generally frusto-conical or tapered lower section 46 is integral with the generally cylindrical upper section 44 and is disposed in essentially angular relation therewith.
  • the angulated lower section 46 is adapted to be received with a correspondingly angulated outer peripheral recess 52 which is defined by the front end 22 of the charge case 12.
  • the yieldable pressure release ring 42 defines at least one and preferably a plurality of pressure relief slots, grooves or channels 54 having the front ends thereof defined by the generally cylindrical upper portion 44 of the yieldable pressure release ring 42 and having the rear ends thereof extending to the rear end 56 of the ring 42.
  • the yieldable pressure release ring 42 is retained at the position shown in Fig. 2 by a crimp ring 60 which is shown in the crimped condition thereof in Fig. 2.
  • the crimp ring encircles the elastomer seal ring as well as the thermoplastic, yieldable pressure release ring.
  • the crimp ring defines an intermediate section 62 which is positioned in encircling relation about the generally cylindrical intermediate section 44 of the yieldable pressure release ring 42 and secures the yieldable pressure release ring intimately about the outer peripheral surface 50 of the front cap 30.
  • the crimp ring 60 in its crimped condition, also has an inclined or generally conical front section 61 which is crimped about an outer peripheral section of the front cap 30 and retains the end cap firmly seated in face to face relation on the planar end surface 28 of the charge case 12.
  • the generally conical section 61 also secures the circular tapered front section 45 of the yieldable pressure release ring in engagement with the tapered front end surface 47 of the front end cap 30.
  • the crimp ring 60 in its crimped condition, further has an inclined or generally conical rear end section 66 which secures the rear end section 46 of the thermoplastic pressure release ring 42 in inclined orientation and seated within the correspondingly inclined outer peripheral groove 52 of the charge case.
  • both the pressure release ring 42 and the crimp ring 60 may be of essentially cylindrical configuration prior to crimping of the crimp ring as shown in Fig. 3.
  • the process of crimping the crimp ring in this case, will deform the pressure release ring from its essentially cylindrical configuration to the angulated cross-sectional configuration shown in detail in Figs. 2 and 4 and will force the rear end of the thermoplastic pressure release ring into the angulated outer peripheral recess 52 at the front end of the charge case.
  • excess charge case pressure can be due to heat induced out-gassing of its explosive composition or due to migration of gas pressure of a well into the charge case.
  • excess charge case pressure can be due to heat induced out-gassing of its explosive composition or due to migration of gas pressure of a well into the charge case.
  • the internal pressure build-up within the internal chamber of the charge case will act on the O-ring sealing member 34 as shown by pressure induced force arrows, causing it to be expanded or moved radially outwardly.
  • portions of the O-ring seal material will be driven into the front end sections of the relief grooves or slots 64.
  • the O-ring seal will have been yielded radially outwardly sufficiently that the excess pressure will bypass the O-ring seal and will be relieved into the relief grooves or slots 64 of the pressure relief member as shown by flow arrows.
  • the relieved pressure from the internal receptacle 26 may then displace the rear end of the pressure relief ring as shown, allowing the excess pressure to be relieved into the environmental medium surrounding the encapsulated shaped charge.
  • the relieved charge pressure can be simply relieved to the atmosphere or to the surrounding environment via the bleed slots of the thermal relief ring. Obviously, the excess internal pressure condition will change, depending whether the encapsulated shaped charge is located at depth within the well and subject to well pressure or whether it is subject to atmospheric pressure.
  • pressure relief will occur slowly as the unfired perforating gun is being moved through the tubing string to the surface, so that pressure bleeding will not occur in the presence of workers at the rig floor.
  • This automatic pressure relieving capability of the encapsulated shaped charge will prevent forcible ejection of the front end cap 30 from the charge case in the event the perforating gun containing the shaped charge is removed from the well in unfired condition.
  • the explosive composition of the internal shaped charge will initially begin out-gassing and internal pressure within the internal receptacle will build up rapidly.
  • the explosive composition will have the tendency to burn rather than detonate.
  • the pressure relief ring 42 may be composed of thermoplastic polymer material so that it will essentially melt when the encapsulated shaped charge is subjected to a condition of heat that is sufficiently elevated to cause rapid out-gassing of the explosive composition of the internal shaped charge.
  • the pressure relief ring melts it will easily yield to internal pressure build-up and will vent excess pressure to the external environment, i.e., typically the atmosphere.
  • the explosive composition will be burned, but, in the absence of sufficient pressure, it will not detonate and cause explosive damage to the surrounding environment.
  • an encapsulated shaped charge shown generally at 70 in Fig. 6 incorporates a charge case 72 that may be essentially identical with the charge case 12 of Fig. 1.
  • An end cap member 74 preferably composed of ceramic material, is seated in face to face relation with the circular front end 76 of the charge case wall 78 and defines a circular seal recess 80 within which is located a circular interference sealing member 82.
  • the end cap 74 may also define an abrupt circular shoulder 86 or the end cap 74 may be of essentially the same geometry as the end cap 30.
  • a crimp ring 88 shown prior to being crimped in Fig.
  • the crimp ring 88 defines a plurality of pressure relief slots or grooves 92 which extend from a region of the crimp ring adjacent to and circumferentially about the circular seal recess 80 to the rear end of the crimp ring.
  • the crimp ring 88 is composed of a low temperature melting alloy which will melt and yield well below the temperature at which the explosive composition of the shaped charge will have any tendency toward detonation
  • the melting point of the low temperature alloy can be designed to suit the out-gassing temperature of the particular explosive composition that is utilized for the explosive charge, I e , approximately 400 degrees F for RDX and 500 degrees F for HNS or PYX, which are explosive compositions that are common in the shaped charges for well casing perforation.
  • Figs 12-14 alternative embodiments of the present invention are shown which permit metal such as carbon steel, heat treated steel, cast iron or steel, bronze, plastics, composite materials or any other suitable material to be used to define a shaped charge cap structure that is designed and manufactured for controlled fracturing when the explosive material of well perforating guns is detonated
  • metal such as carbon steel, heat treated steel, cast iron or steel, bronze, plastics, composite materials or any other suitable material to be used to define a shaped charge cap structure that is designed and manufactured for controlled fracturing when the explosive material of well perforating guns is detonated
  • metal such as carbon steel, heat treated steel, cast iron or steel, bronze, plastics, composite materials or any other suitable material
  • a shaped charge cap shown generally at 100 is of circular, essentially domed configuration, though its configuration is not considered critical to the present invention
  • the cap structure 100 may be of any of a number of acceptable shapes without departing from the spirit and scope of the present invention
  • the shaped charge cap 100 defines a plurality of generally radially oriented fracture grooves 102 which extend from the central portion of the cap structure to side portions of the cap structure as shown and thus define predetermined stress concentration points or lines throughout the cap structure
  • the number and orientation of the fracture grooves is designed according to the character of the material to be fractured
  • the fracture grooves may be disposed in generally radially oriented relation as shown in Figs. 12- 14 or additionally transversely oriented fracture grooves may be employed as partially shown in Figs. 12 and 13 at 103.
  • the cap 100 with stress concentrating features or fracture grooves of any suitable geometric design that enables the explosive jet of shaped charge detonation to fracture the cap into sufficiently small sections that will not impede the conduct of other well construction or servicing operations.
  • This feature will permit the cap structure to be composed of a wide variety of materials such as any of a number of suitable metals, i.e., heat-treated carbon steels, cast iron, steel and suitable non-metal materials such as plastics, ceramic material and the like.
  • the cap may also be composed of metal or non-metal composite materials if desired.
  • the forces of detonation of the explosive composition within the charge case will cause the cap structure to be fractured at least along the various radiating fracture lines or stress concentration points or lines 102 so that the cap will be fractured into a multiplicity of small sections according to the design of the stress concentration features.
  • additional fracture grooves may be formed in the cap structure which may be oriented other than radially, so that fracture of the cap structure into a multiplicity of small sections is ensured regardless of the material from which the cap is composed when the explosive jet of the shaped charge passes through the cap.
  • the cap 104 is shown to be essentially of the circular, domed configuration shown in Figs. 12 and 13.
  • the cap 104 is also shown to be provided with a plurality of fracture grooves or stress concentration points 106 which radiate from the central portion of the cap to the circular edge of the cap essentially as described in connection with Fig. 12 and 13.
  • the cap structure 104 defines a generally circular fracture groove or stress concentration point or line 108 which is located centrally of the cap and thus enhances fracturing of the central portion of the cap into a multiplicity of small sections or particles responsive to passage of the explosive jet therethrough upon detonation of the shaped charge.
  • any suitable fracture grooves or stress concentration points or lines may be defined by a shaped charge cap structure to ensure orderly, designed fragmenting thereof responsive to the force of detonation of the explosive charge.
  • a wide variety of materials may be considered for construction of a shaped charge cap structure which would not ordinarily be acceptable.

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Abstract

L'invention concerne une charge de perforation formée (10) à expansion intégrale et fermée hermétiquement, consistant en une enveloppe de charge (12) délimitant une chambre interne (26) contenant une charge explosive formée. Un capuchon (30) est fixé sur l'enveloppe (12) et, afin que la fracturation soit accrue, peut être constitué de matériau céramique. Le capuchon (30) peut également être en matériau métallique, polymère ou composite délimitant des rainures de fracture (102) formant des points ou des lignes de concentration de contraintes pour la fracturation contrôlée de ceux-ci par le jet explosif de la charge, de manière que les fragments soient suffisamment petits et qu'il ne nuisent pas à la construction ou à la maintenance du puits. Le capuchon (30), quelle que soit sa composition, peut être fixé à l'enveloppe (12) par une bague de sertissage (60) appliquée sur un élément de libération thermoplastique (42) et un anneau d'étanchéité élastomère (40) qui assure l'étanchéité entre l'enveloppe (12) et le capuchon (30), de manière que la pression du puits soit évacuée de la chambre interne (26) de l'enveloppe (12) et du capuchon (30). La bague de détente efficace (60) permet à la pression de dégazage interne au sein de la chambre interne d'être évacuée par des fentes de purge (54), ce qui empêche l'éjection violente du capuchon (30) de l'enveloppe (12) lors du retrait du canon du puits sans qu'il ait été utilisé.
PCT/US2000/018486 1999-07-13 2000-07-06 Charge formee encapsulee pour perforation de puits WO2001004452A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU62061/00A AU6206100A (en) 1999-07-13 2000-07-06 Encapsulated shaped charge for well perforation

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US14346899P 1999-07-13 1999-07-13
US60/143,468 1999-07-13
US56980500A 2000-05-12 2000-05-12
US09/569,805 2000-05-12

Publications (1)

Publication Number Publication Date
WO2001004452A1 true WO2001004452A1 (fr) 2001-01-18

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2000/018486 WO2001004452A1 (fr) 1999-07-13 2000-07-06 Charge formee encapsulee pour perforation de puits

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AU (1) AU6206100A (fr)
WO (1) WO2001004452A1 (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005035940A1 (fr) * 2003-10-10 2005-04-21 Qinetiq Limited Ameliorations apportees et relatives a des perforateurs
GB2430479A (en) * 2005-03-08 2007-03-28 Schlumberger Holdings Apparatus for controling explosive energy generated by a shaped charge in a perforating tool in a wellbore
WO2015030732A1 (fr) * 2013-08-27 2015-03-05 Halliburton Energy Services, Inc. Explosifs encapsulés pour le forage de puits de forage
EP3132229A4 (fr) * 2014-04-15 2017-12-06 Hunting Titan, Inc. Système d'évacuation des gaz pour charge creuse en cas de déflagration
EP3278052A4 (fr) * 2015-04-02 2018-10-10 Hunting Titan, Inc. Dispositif de retenue de revêtement encliquetable
EP2992093B1 (fr) 2013-04-30 2020-03-18 Henkel AG & Co. KGaA Produit détergent contenant des protéases
US10954760B2 (en) 2017-11-29 2021-03-23 DynaEnergetics Europe GmbH Closure member and encapsulated slotted shaped charge with closure member
US11340047B2 (en) 2017-09-14 2022-05-24 DynaEnergetics Europe GmbH Shaped charge liner, shaped charge for high temperature wellbore operations and method of perforating a wellbore using same
WO2022135749A1 (fr) * 2020-12-21 2022-06-30 DynaEnergetics Europe GmbH Charge creuse encapsulée
USD981345S1 (en) 2020-11-12 2023-03-21 DynaEnergetics Europe GmbH Shaped charge casing
US11661824B2 (en) 2018-05-31 2023-05-30 DynaEnergetics Europe GmbH Autonomous perforating drone

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US4496008A (en) * 1980-08-12 1985-01-29 Schlumberger Technology Corporation Well perforating apparatus
US4881445A (en) * 1988-09-29 1989-11-21 Goex, Inc. Shaped charge
US5088557A (en) * 1990-03-15 1992-02-18 Dresser Industries, Inc. Downhole pressure attenuation apparatus
US5155293A (en) * 1990-12-13 1992-10-13 Dresser Industries, Inc. Safety booster for explosive systems
US6098707A (en) * 1998-04-24 2000-08-08 The Ensign-Bickford Company Perforation gun for well casing

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US4496008A (en) * 1980-08-12 1985-01-29 Schlumberger Technology Corporation Well perforating apparatus
US4881445A (en) * 1988-09-29 1989-11-21 Goex, Inc. Shaped charge
US5088557A (en) * 1990-03-15 1992-02-18 Dresser Industries, Inc. Downhole pressure attenuation apparatus
US5155293A (en) * 1990-12-13 1992-10-13 Dresser Industries, Inc. Safety booster for explosive systems
US6098707A (en) * 1998-04-24 2000-08-08 The Ensign-Bickford Company Perforation gun for well casing

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9267362B2 (en) 2003-10-10 2016-02-23 Qinetiq Limited Perforators
WO2005035940A1 (fr) * 2003-10-10 2005-04-21 Qinetiq Limited Ameliorations apportees et relatives a des perforateurs
GB2430479A (en) * 2005-03-08 2007-03-28 Schlumberger Holdings Apparatus for controling explosive energy generated by a shaped charge in a perforating tool in a wellbore
GB2430479B (en) * 2005-03-08 2007-08-08 Schlumberger Holdings Energy controlling device
EP2992093B1 (fr) 2013-04-30 2020-03-18 Henkel AG & Co. KGaA Produit détergent contenant des protéases
WO2015030732A1 (fr) * 2013-08-27 2015-03-05 Halliburton Energy Services, Inc. Explosifs encapsulés pour le forage de puits de forage
CN105378216A (zh) * 2013-08-27 2016-03-02 哈利伯顿能源服务公司 用于钻探井筒的封装炸药
GB2532884A (en) * 2013-08-27 2016-06-01 Halliburton Energy Services Inc Encapsulated explosives for drilling wellbores
EP3132229A4 (fr) * 2014-04-15 2017-12-06 Hunting Titan, Inc. Système d'évacuation des gaz pour charge creuse en cas de déflagration
EP3278052A4 (fr) * 2015-04-02 2018-10-10 Hunting Titan, Inc. Dispositif de retenue de revêtement encliquetable
US11340047B2 (en) 2017-09-14 2022-05-24 DynaEnergetics Europe GmbH Shaped charge liner, shaped charge for high temperature wellbore operations and method of perforating a wellbore using same
US10954760B2 (en) 2017-11-29 2021-03-23 DynaEnergetics Europe GmbH Closure member and encapsulated slotted shaped charge with closure member
US11492877B2 (en) 2017-11-29 2022-11-08 DynaEnergetics Europe GmbH Closure member and encapsulated slotted shaped charge with closure member
US11661824B2 (en) 2018-05-31 2023-05-30 DynaEnergetics Europe GmbH Autonomous perforating drone
USD981345S1 (en) 2020-11-12 2023-03-21 DynaEnergetics Europe GmbH Shaped charge casing
WO2022135749A1 (fr) * 2020-12-21 2022-06-30 DynaEnergetics Europe GmbH Charge creuse encapsulée

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