초록 ▼

An electrically operated firing piston is provided for effecting the firing of a perforating gun in a subterranean well. The electrical firing system is disposed within a hollow housing which is detachably secured to the gun and is subject to the fluid pressures surrounding the perforating gun. The

An electrically operated firing piston is provided for effecting the firing of a perforating gun in a subterranean well. The electrical firing system is disposed within a hollow housing which is detachably secured to the gun and is subject to the fluid pressures surrounding the perforating gun. The electrical firing system is armed through the application of a fluid pressure to the exterior of the housing which is in excess of the well hydrostatic pressure, thereby preventing premature firing of the perforating gun before insertion at its desired position in the well. The generation of an electrical firing pulse is controlled by a microprocessor which is preset to be responsive only to a selected value of fluid pressure surrounding the control housing. Thus, the pressure surrounding the perforating gun may be reduced to a selected under-balanced condition before the firing of the gun can be effected.

대표청구항 ▼

In a mechanism for electrically firing a tubing supported perforating gun in a subterranean well comprising: a housing insertable in the tubing and releasably securable to the perforating gun, said housing containing a power supply, electrical means for generating an electrical gun firing pulse and

In a mechanism for electrically firing a tubing supported perforating gun in a subterranean well comprising: a housing insertable in the tubing and releasably securable to the perforating gun, said housing containing a power supply, electrical means for generating an electrical gun firing pulse and a mechanical switch for connecting said power supply to said electrical means; a hydrostatic pressure responsive rupture disc forming a wall of said housing; a cylinder mounted within said housing, whereby the rupture of said rupture disc by increasing the fluid pressure in the tubing permits said fluid pressure to be applied to said cylinder; and a piston slidably and sealably mounted in said cylinder and operatively connected to said mechanical switch to close same in response to the rupture of said rupture disc. The method of firing a perforating gun in a subterranean well under optimum fluid pressure conditions surrounding the perforating gun comprising the steps of: suspending the perforating gun adjacent a production formation by a tubing string extending to the well surface, said tubing string incorporating a packer engagable with the well bore above said perforating gun; disposing a hollow housing adjacent to said perforating gun and having its interior isolated from well fluids by a fluid pressure operated valve responsive to a first level of pressure of fluid surrounding said perforating gun, said housing containing an electrical power source, a fluid pressure transducer, a microprocessor and an electrical firing pulse generator; connecting said power source to said microprocessor in response to the opening of said valve; and, energizing said electrical firing pulse generator by said microprocessor in response to a signal from said fluid pressure transducer indicating the existence of a second preselected fluid pressure level surrounding said perforating gun.