Abstract: A perforating gun assembly that includes at least one component that is constructed from a composite material and that is impermeable to wellbore fluids. The components may include the outer carrier and/or loading tube of a perforating gun, the connecting tubing of a gun release mechanism, and the gun connector used to attach adjacent perforating guns. The composite material is designed to be very brittle under dynamic impact. The component is made impermeable to wellbore fluids by including an impermeable liner therein. The impermeable liner can be bonded to the inner or outer surface of the component or can be embedded within the component. Since it is brittle under dynamic impact, the composite component shatters into small pieces upon detonation of the perforating gun.

Abstract: A gun system in one arrangement includes a first carrier including a detonating cord and a second carrier including a detonating cord. An adapter couples the first and second carriers, with the adapter including an explosive coupled to the detonating cord of one of the first and second carriers. The explosive is positioned in a reduced housing portion of the adapter. The reduced housing portion of the adapter has a first outer diameter less than an inner diameter of the first carrier to provide a predetermined annular space between the reduced adapter portion and the inner diameter of the first carrier. At least one of the detonating cords in the first and second carriers is attached to a retainer element, and the retainer element is placed in close proximity to the explosive to maintain an axial position of the detonating cord to reduce separation between the detonating cord and the explosive.

Abstract: A method includes arranging shaped charges in a perforating gun to produce perforation holes in a helical pattern that is defined in part by a phase angle; and choosing four adjacent perforation holes to be created that are adjacent nearest neighbors. The distances are determined between three of the four adjacent perforation holes to be created. A standard deviation is minimized between the three adjacent perforation holes. The phase angle is set based on the minimization.

Abstract: A tool string for use in a well includes a filter sub (or trapped pressure regulator sub) that is used with other components to reduce trapped pressure. The filter sub filters out debris that may occur from various types of downhole operations, such as perforating operations. By filtering out larger debris, only gases, liquids, and smaller particles are allowed to enter various components of the tool string. Without the presence of larger solid debris inside certain components of the tool string, the likelihood of plugs being formed is reduced so that gases and liquids can more readily pass out of the tool string as the tool string is retrieved to the surface of the well and the well hydrostatic pressure decreases.

Abstract: Apparatus and method for cooling a component inside a tool includes a container and a plurality of heat sinks positioned in the container. The components are positioned in the container with the heat sinks for maintaining a reduced temperature inside the container. Further, an insulating layer and a reflective layer surround the heat sinks and components to reduce heat transfer. Alternatively, the container can have a hollow wall that encloses the space in which a heat sink material (such as an eutectic material) is disposed. The components to be protected are located in the container. The eutectic material includes a composition having tin and zinc. The insulating layer includes a container that stores a vacuum layer, such as a dewar flask.

Abstract: A shaped charge for use in perforating formation adjacent a wellbore includes a liner having a substantially non-conical shape (also referred to as bowl-shaped). The liner has first and second layers, with a first layer contacting the main explosive charge. The second layer (made of such materials as copper, silver, gold, and so forth) contributes primarily to formation of a perforating jet while the first layer contains a material that substantially disintegrates upon detonation such that formation of a slug is reduced or eliminated.

Abstract: A loading tube of a perforating gun includes a plurality of mating holes, where each mating hole has a specific and predetermined contour, and a case of a shaped charge, adapted to fit within the mating hole, includes a pair of retaining lugs and a pair of shoulder lugs, which lugs are adapted to uniquely cooperate with the contour of the mating hole of the loading tube for securing the shaped charge to the loading tube. The predetermined contour of each mating hole includes a pair of slots disposed opposite one another in the mating hole, and a pair of grooves disposed opposite one another in the mating hole but offset from the pair of slots. Each pair of grooves includes a large radius groove and a small radius groove. The pair of retaining lugs of the shaped charge case are adapted to be received, respectively, in the pair of slots of the contour of the mating hole; whereas the pair of shoulder lugs are adapted to be initially received in the pair of large radius grooves of the contour of the mating hole.

Abstract: A loading tube of a perforating gun includes a plurality of mating holes, where each mating hole has a specific and predetermined contour, and a case of a shaped charge, adapted to fit within the mating hole, includes a pair of retaining lugs and a pair of shoulder lugs, which lugs are adapted to uniquely cooperate with the contour of the mating hole of the loading tube for securing the shaped charge to the loading tube. The predetermined contour of each mating hole includes a pair of slots disposed opposite one another in the mating hole, and a pair of grooves disposed opposite one another in the mating hole but offset from the pair of slots. Each pair of grooves includes a large radius groove and a small radius groove. The pair of retaining lugs of the shaped charge case are adapted to be received, respectively, in the pair of slots of the contour of the mating hole; whereas the pair of shoulder lugs are adapted to be initially received in the pair of large radius grooves of the contour of the mating hole.

Abstract: A perforating apparatus adapted to be disposed in a wellbore includes a plurality of shaped charges, an electrical current carrying conductor, and a plurality of exploding foil or exploding bridgewire initiators disposed, respectively, between the plurality of charges and the current carrying conductor for simultaneously detonating thereby simultaneously detonating all of the plurality of shaped charges of the perforating apparatus in response to a current flowing in the conductor. Each of the shaped charges include a new secondary explosive primer disposed in the apex of the charge for detonating in response to a detonation of the exploding foil or exploding bridgewire initiator. The electrical conductor may include a flat cable having a plurality of such initiators spaced apart at predetermined intervals along the cable and adapted to wrap helically around the perforating apparatus until each of the initiators abut against a shaped charge of the plurality of charges in the perforating apparatus.

Abstract: A new method and apparatus for performing a drill stem test in an open (not cased) borehole are disclosed. When the borehole is initially drilled, the drilling process induces a skin damage near the external surface of the open (not cased) wellbore. It is necessary and desirable to bypass, reduce, or eliminate the skin damage in order to provide a free or natural flow of well fluid from the reservoir in the formation into the wellbore. However, in order to determine the degree of skin damage which exists near the external surface of the wellbore, reservoir parameters such as pressures, temperature and flowrates of the formation fluid flowing from the reservoir into the wellbore is first measured in the presence of the skin damage. The skin damage is then bypassed, removed, eliminated, or reduced by, for example, perforating the external surface of the wellbore.

Abstract: Various charge phasing arrangements in a perforating gun include those uniquely associated with phasing solely along a 180 degree circumference of the perforating gun, for use in but not limited to deviated boreholes. One phasing arrangement comprises four rows of charges, four corresponding rows of recesses in the perforating gun carrier and four corresponding rows of holes in the loading tube, the recesses, holes and charges being constrained within a 180 degree circumference of the perforating gun. The two outermost rows have more recesses, more holes and more charges than do the two innermost rows, since more well fluid is interposed between the two outermost rows and the casing than is interposed between the two innermost rows and the casing of the borehole.