Abstract: A differential pressure actuated vent assembly is connected into an oil well tool string. In one form of the invention, the tool string includes a packer device, a perforating gun attached to the lower end of the tubing string, with the vent assembly being interposed between the gun and the packer device. Fluid pressure within the tubing string is effected on one face of a piston associated with the vent assembly, which reciprocates the piston and communicates the interior of the tubing string with the annulus around the tubing string while carrying out the step of perforating the formation. Movement of the piston and the subsequent detonation of the gun preferably are both accomplished sequentially in response to the dropping of a bar down through the tool string. The bar opens a passageway leading to the piston, and immediately thereafter, before the pressure differential between the interior of the tubing string and the annulus is equalized, the gun is detonated, thereby obviating damage to the formation.

Abstract: A hold down apparatus for a wireline operated perforating gun which prevents the gun from being thrust uphole when the gun is fired. The hold down apparatus enables the gun to be run downhole in a tubing or casing string, without the necessity of filling the pipe with liquid. The hold down apparatus includes a releasable anchor apparatus which is selectively set when the gun is manipulated vertically in a particular manner by the wireline. The gun is run downhole and positioned at the zone where the perforations are to be formed. The gun is lifted a finite distance, then lowered a finite distance, and then lifted again, thereby setting a pair of slips which are located in underlying relationship with respect to the gun. The gun remains anchored downhole so long as tension is maintained on the wireline. The gun is fired and subsequently released by lowering the gun a finite distance whereupon the anchoring device releases the slips from engagement with the piping. The gun can then be lifted uphole.

Abstract: The method and apparatus for actuating a perforating gun by pressure includes a pressure actuated gun firing head disposed on the perforating gun for detonating the shaped charges of the gun. The gun is attached to a pipe string and located downhole adjacent the formation to be perforated. The pressure actuated firing head includes a housing with a plug and piston. The piston has a firing pin adapted for engagement with the initiator of a perforating gun upon reciprocation within the housing. Initially, the piston is pressure balanced until the time of actuation. The plug is responsive to fluid pressure of a predetermined magnitude at the time of the actuation of the gun firing head. Upon effecting pressure on the plug, the plug unbalances the piston causing the piston to reciprocate. Upon reciprocation of the piston, the firing pin engages the initiator to detonate the shaped charges of the perforating gun. Pressure may be effected on the firing head through the pipe string, or the annulus, or both.

Abstract: A perforating gun is suspended downhole in a cased borehole, in underlying relationship relative to a packer device, and adjacent to a hydrocarbon-bearing formation to be completed. A connecting tubing interconnects the gun with the packer device, and includes a rupture barrier therebetween which prevents debris from accumulating within a gun firing head. An upper tubing string is removably connected to the packer device and forms a passageway which extends from the surface of the earth, down through the packer, and to the gun firing head. The upper tubing string includes a seal means and an extension tube which sealingly engages the packer device and penetrates the rupture barrier to provide a passageway through which the gun can be fired from the surface of the earth. This combination of elements prevents malfunction of the gun when the tool is left downhole for an appreciable length of time.

Abstract: A vent assembly is positioned downhole in a borehole in underlying relationship with respect to a packer device. The vent assembly is connected within a production tubing string and a perforating gun is supported by the lower end of the string. A bar of special design is dropped down through the interior of the tubing and falls through the vent assembly and continues to fall down the tubing string to impact against a gun firing head. The action of the bar passing through the vent assembly moves structures associated therewith to cause a port to assume an open position. The subsequent impact of the bar against the gun firing head detonates the shaped charges of the gun. Formation fluid is then free to flow into the perforations, up the lower annulus, into the port of the vent assembly, and up the production tubing to the surface of the ground.

Abstract: A cased borehole has a perforating gun suspended in underlying relationship relative to a packer device. A tubing string has a seal assembly connected to the lower end thereof, and an extension tube downwardly extends from the seal assembly. A seal housing is connected to the packer and receives the seal assembly therewithin. The tubing string is run downhole until the end of the extension tube is in proximity of a gun firing head while the seal assembly is unseated from the housing, so that the fluid in proximity of the gun firing head is displaced with clean fluid which flows from the surface, down the tubing string, and out of the end of the extension tube.

Abstract: A perforating gun is suspended downhole in a cased borehole, in underlying relationship relative to a packer device, and adjacent to a hydrocarbon-bearing formation to be completed. A connecting tubing interconnects the gun with the packer device, and includes a rupture barrier therebetween which prevents debris from accumulating within a gun firing head. An upper tubing string is removably connected to the packer device and forms a passageway which extends from the surface of the earth, down through the packer, and to the gun firing head. The upper tubing string includes a seal means and an extension tube which sealingly engages the packer device and penetrates the rupture barrier to provide a passageway through which the gun can be fired from the surface of the earth. This combination of elements prevents malfunction of the gun when the tool is left downhole for an appreciable length of time.

Abstract: A method of recompleting or controlling the flow of a formation which is inaccessible through the original wellbore and which is losing valuable hydrocarbons to another formation. A second borehole is formed in close proximity to the first wellbore, and at least the bottom end of the new borehole is slanted until it penetrates the hydrocarbon bearing formation within shooting distance of the bottom end of the first wellbore. A large casing gun is run downhole through the new borehole. All of the shaped charges of the gun are oriented in the same direction. Indexing means are included by which all of the shaped charges of the gun are oriented to fire towards the casing of the first wellbore. After the gun is discharged, cement is pumped down the borehole, through the tunnels formed by the shaped charges, and into the perforations of the wellbore casing, thereby killing the flow of hydrocarbons from the damaged wellbore.

Abstract: A pressure actuated vent assembly for completing a slanted wellbore. The assembly is connected in series relationship within a tubing string at a location below a packer, and the packer elements are located between the casing and the tubing string, thereby dividing the casing annulus into an upper and lower annular area. The vent assembly includes a ported sliding sleeve which is slidably received about a ported main body member. The sleeve is held into position by a shear pin. Guide pins maintain the ports of the sleeve and main body member aligned with one another. When pressure is applied to the inside of the tubing, the sliding sleeve is forced to slide from an upper closed position, in a downward direction, where the sleeve locks into the opened position.

Abstract: A pressure actuated vent assembly for completing a slanted wellbore. The assembly is connected in series relationship within a tubing string at a location below a packer, and the packer elements are located between the casing and the tubing string, thereby dividing the casing annulus into an upper and lower annular area. The vent assembly includes a ported sliding sleeve which is slidably received about a ported main body member. The sleeve is held into position by a shear pin. Guide pins maintain the ports of the sleeve and main body member aligned with one another. When pressure is applied to the inside of the tubing, the sliding sleeve is forced to slide from an upper closed position, in a downward direction, where the sleeve locks into the opened position.

Abstract: A casing gun is suspended downhole adjacent to a hydrocarbon containing formation by attaching the gun to the end of a tubing string. A packer device isolates the lower downhole casing annulus from the upper casing annulus. The casing gun has a firing head located at the upper end thereof which is actuated in response to impact. A vent assembly underlies the packer and is connected in series relationship respective to the gun firing head and the packer. A specially constructed bar device is dropped into a lubricator at the wellhead and travels down the interior of the tubing string, where the bar impacts against a sliding sleeve of the vent assembly, thereby moving the sleeve and opening a port which communicates the interior of the tubing string with the lower casing annulus. The bar continues to travel downhole until it impacts against the firing head, thereby detonating the perforating gun.

Abstract: A packer actuated vent assembly comprising a packer device settable by reciprocal movement of a mandrel, a valve actuator in the form of a barrel attached to the packer body, and a mandrel extension having a valve means thereon attached to the packer mandrel. The valve means is engaged by a stop member located on the barrel and is moved to the venting position when the packer mandrel is properly manipulated to seat the packer.

Abstract: A packer actuated vent assembly comprising a packer device settable by reciprocal movement of a mandrel, a valve actuator in the form of a barrel attached to the packer body, and a mandrel extension having a valve means thereon attached to the packer mandrel. The valve means is engaged by a stop member located on the barrel and is moved to the venting position when the packer mandrel is properly manipulated to seat the packer.