Schlumberger Technology Corporation

Other

US Government As Represented by the Secretary of the Army

Schlumberger Technical Corporation

Clifford L Aseltine

James E Brooks

Nolan C Lerche

Manuel T Gonzalez

Terrell E Dailey

Erik B Nelson

Robert A Parrott

Wallace E Voreck

Gould Gibbons, Jr

Frank M Williams

Kenneth Edmund Rozek

Philip M Howe

Jerome J Jacoby

Charlie S Stulb

The perforating device for use in completing a well includes a case, an explosive charge contained in the case, and a generally bowl-shaped liner. The liner is positioned adjacent the explosive charge and has non-uniforrn thickness along its length. The liner further includes a protruding portion near its tip. In another configuration, the liner includes a hole near its tip to expose a portion of the explosive charge.

Perforating devices for use in wells

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. In an alternate embodiment, the electrical current carrying conductor may include a flat sheet having a specific length and width and including a plurality of such initiators. The flat sheet is adapted to wrap around the entire circumference of the perforating apparatus until each of the initiators in the sheet abut against a shaped charge of the plurality of charges in the perforating apparatus. The current in the conductor may originate from a compressed magnetic flux (CMF) current pulse generator or from a charging capacitor of a conventional system including one or more charging capacitors and associated discharge switches. When the perforating apparatus includes a first and second perforator separated by an adaptor, the adaptor includes a pressure bulkhead adapted to seal the first perforator from the second perforator, an explosive disposed in contact against one side of the bulkhead and a piezoelectric ceramic disposed in contact against the other side of the bulkhead.

Perforating gun having a plurality of charges including a corresponding

Prior to pumping completion brine fluid into a wellbore, an additive comprising two percent (2%) of a 0.25% solution of polyacrylamide is blended into the completion brine fluid thereby producing a treated brine fluid. This blending would be performed in tanks at the wellsite. The treated brine fluid is then pumed into the wellbore. In addition, or in the alternative, a new perforating gun stores the polyacrylamide additive composition. When the perforating gun detonates, the additive is disbursed into the completion brine fluid disposed in the annulus of the wellbore. For example, the new perforating gun may include a plurality of shaped charges coated with a lacquer of the polyacrylamide additive, or it may include one or more containers which contain the polyacrylamide additive. When the brine completion fluid is pumped into the wellbore annulus, a detonation wave conducts in a detonating cord of the perforating gun. The detonation wave passes through each of the containers. As a result, the containers will rupture and the plurality of shaped charges will detonate. Since the containers each ruptured, the polyacrylamide additive composition from the containers will be disbursed into the brine completion fluid in the annulus. In addition, or in the alternative, since the shaped charges of the new perforating gun were coated with a lacquer of the polyacrylamide composition, when the shaped charges detonated, the polyacrylamide composition on the zinc charge debris mixes with the brine fluid in the wellbore annulus. Zinc oxychloride hydrate debris is formed as a reaction product. However, the presence of the polyacrylamide additive in the zinc oxychloride hydrate debris will inhibit the formation of hardened chunks of a cement-like material in the annulus of the wellbore.

Apparatus and method for mixing polyacrylamide with brine in an annulus

A firing head for a firing system adapted for use in a perforating gun includes an outer pressure bulkhead housing which simultaneously conducts two separate and independent currents: a wireline current from a wireline and a return current from an initiator embodied in the firing head. A fire set circuit provides a discharge pulse to the firing head, and a wireline conductor cable provides a wireline current to the fire set circuit. The firing head includes an outer pressure bulkhead housing adapted for conducting the wireline current from the wireline conductor cable to the fire set circuit, and an exploding foil initiator (EFI) responsive to the discharge pulse from the fire set circuit for initiating the detonation of a secondary explosive. The discharge pulse energizing the firing head passes through the exploding foil initiator (EFI) and emerges from the EFI as an EFI return current. As a result, the outer pressure bulkhead housing of the firing head conducts two separate and independent currents: the EFI return current from the EFI to a ground potential, and the wireline current from the wireline conductor cable to the fire set circuit.

Firing system for a perforating gun including an exploding foil

A perforating gun apparatus comprises a plurality of perforating gun, each gun containing at least one charge and a novel arming, testing and firing apparatus. The arming, testing and firing apparatus arms a first charge in a lowermost perforating gun; however, the arming of the first charge in the lowermost perforating gun allows a tester disposed at the well surface to determine the identity of the lowermost perforating gun to be detonated. Furthermore, the arming of the first charge in the lowermost perforating gun also enables the arming of a second charge in an adjacent perforating gun of the gun string. In the event the first charge is not armed as expected, the arming, testing and firing apparatus in the lowermost perforating gun bypasses the lowermost perforating gun and begins to arm the second charge in the adjacent perforating gun of the gun string. A novel housing for a perforating gun includes an isolated chamber in which a charge is mounted, the chamber having two opposite walls, one wall being circumferentially rotatable and including a radially disposed detonator. Since a detonating cord is longitudinally disposed in the chamber, the circumferentially rotatable characteristic of the one wall in association with the radial disposition of the detonator provides a safe arm feature of the perforating gun.

Apparatus for arming, testing, and sequentially firing a plurality of

A safe-arm or quick arm system for a perforating gun includes a body containing a detonator and an adapter head containing an electrical plug and a detonating cord shell, the body and associated detonator being rotatable relative to the adapter head and associated detonating cord shell. Upon rotation of the body relative to the adapter head, the detonator moves from a start position to a transport position. In this position, the plug is not electrically connected to the detonator and the leads connected to the detonator are short circuited. The detonator is not adapted to receive electrical power. Upon further rotation of the body relative to the adapter head, the detonator moves from the transport position to an electrical contact position. In this position, the plug is electrically connected to the detonator but the detonator is not aligned with the detonating cord shell. Upon further rotation of the body relative to the adapter head, the detonator moves from the electrical contact position to the armed position. In this position, the plug is electrically connected to the detonator and the detonator is aligned with the detonating cord shell.

Safe arm system for a perforating apparatus having a transport mode an

A unique structure for the shaped charge allows the formation of a uniquely configured jet with an alternating velocity gradient along its length. In a preferred embodiment, the velocity of material within the jet is significantly greater at two points along its length than elsewhere. As a result, the material of the jet 'bunches up' at these points, forming two bulges. The forwardmost bulge is expended as it breakes through the gun wall and travels through the borehole fluid. The second bulge grows as the jet traverses the annular space between the gun wall and the casing, providing a large diameter mass to impact the casing and form a large diameter hole therein.

Shaped charge apparatus and method

Propagation of detonation between pallets of munition such as artillery sls is prevented by interposing an inert material having adequate density to render the fragments from a detonating pallet non-lethal when they reach explosive devices in a neighboring pallet. The material must be of a type which does not itself form lethal fragments and the material must be placed sufficiently close to the explosive devices that the fragments from an explosive have not had time to separate into individual pieces but, instead, produce a plate impact on the material. This latter requirement reduces or eliminates the need for any substantial strength in the material.

Growing community of inventors

Houston, TX, United States of America

Clifford L Aseltine