Halliburton Company

Halliburton Logging Services, Inc.

Larry L Grigar

James Marshall Barker

Carl B Miller

Gregory N Gilbert

Martin L Tomek

Robert R Luke

Michael L Smith

John W Jordan

Dennis E Schramek

Terry L Slagle

Cyril R Sumner

Starlin M Reid

A perforating gun assembly is set forth. It incorporates a swivel connected with a cable head assembly and a navigation system for determining the instantaneous angle of the tool with respect to a vertical reference. There are first and second spaced cages formed of sleeves supported on bearing assemblies. The sleeves support free wheeling rollers which engage the casing when the tool is in the slant hole region of the well. There is an eccentric which falls downwardly, i.e., pointing toward gravity, and thereby defines a vertical reference and hence a horizontal reference. This eccentric mounts an elongate tubular housing for the shaped charges. Initially, the angle of firing of the shaped charges is adjusted at the time of installation with respect to the horizon and that in turn is correlated to the formation of interest in the well borehole which is then perforated with perforations which are parallel to the formation bedding plane.

Wireline supported perforating gun enabling oriented perforations

For use in a perforating gun assembly, a perforating gun detonator is disclosed. One embodiment is hermetically sealed while the other has openings therein to admit well fluids. In both embodiments, a narrow conductive metal foil is provided with a current to vaporize the narrow foil, explode the foil and propel a flyer driven by a shock wave for detonation of a spaced secondary explosive. The explosive then couples explosion into a detonating cord against a shoulder in a housing adjacent to the secondary explosive. The current is formed by means of an AC voltage multiplier circuit providing a charge on a capacitor which is discharged through a spark gap. Charging circuitry includes a blocking capacitor to prevent DC and a resistor for bleeding a small current from the capacitor to ground which prevents static or stray current accumulation.

Downhole perforating method and apparatus using secondary explosive

In an exposed perforating gun assembly, contact with well fluids at high pressure and temperature is detrimental to explosives in the explosive train. This device protects such explosives and includes a cylindrical housing with a bore having an electrical feedthrough at one end, an enclosed initiator, a cooperative sleeve and cooperative sealed retainer. The detonating cord is sealed into proximity with the initiator and is held against high pressure extrusion by the sealed retainer.

Through bulkhead explosive initiator for oil well usage

In a tubing conveyed perforating gun assembly having shaped charges to perforate a well, an improved pressure sequence shaped charge detonator is included. The preferred form of device is appended to the bottom of the assembly to function as a backup detonator. First and second piston and cylinder assemblies in an elongate body provide pressure initiated arming and subsequent pressure initiated firing pin movement to achieve primer cord detonation for perforation of the well. The pressure sequence is controllable, selectively to a specified pressure to arm and thereafter to fire.

Tubing pressure operated initiator for perforating in a well borehole

In tubing conveyed perforating well completion operations, shaped charge detonation is achieved by dropping a detonating bar in the tubing string. Velocity of the detonating bar is controlled by placing a column of standing fluid above the tubing conveyed perforating assembly. This apparatus and method isolate a column of standing fluid. Moreover, invasion by a well fluid is prevented to assure that the retardation characteristics of the standing fluid are not changed by invading well fluids. The apparatus includes a tubing string pressure isolation piston assembly slidable within a sleeve and a frangible closure disk broken by the detonating bar; the isolation tool further includes check valve means controllably venting fluid pressure across the valve means.

Balanced isolation tool enabling clean fluid in tubing perforated

For use with a tubing conveyed perforating gun assembly, a wireline manipulated electrically actuated detonator assembly traversing the interior of the tubing is described. In the preferred and illustrated embodiment, a wireline connected with a sinker bar supports the detonator assembly having a sinker bar sub terminating in a taper adjacent to a set of deflectable collet fingers comprising a latch assembly. The collet fingers are deflected outwardly by the tapered surface and are forced into an undercut located above a booster and detonating cord affixed to the tubing conveyed perforating gun assembly for firing the perforating guns.

Growing community of inventors

East Bernard, TX, United States of America

Larry L Grigar