초록 ▼

A method and apparatus for effecting the firing of a perforating gun having a plurality of vertically spaced, shaped charges wherein the firing is accomplished from the lowermost shaped charge to the uppermost shaped charge. In one modification, the detonation of the shaped charges is accomplished b

A method and apparatus for effecting the firing of a perforating gun having a plurality of vertically spaced, shaped charges wherein the firing is accomplished from the lowermost shaped charge to the uppermost shaped charge. In one modification, the detonation of the shaped charges is accomplished by a primer cord extending through all the gun sections, which is detonated only by a booster charge located in the bottom portion of the perforating gun housing. The booster charge is in fluid communication with the interior of the housing and, upon the occurrence of leakage of well fluids into the housing, the booster charge is rendered ineffective, thus preventing the firing of the perforating gun when the lower portion of the gun is filled with well fluids. In another modification, a conventional primer cord with booster charges on each end is inserted in each gun section, as is a length of flame-transmitting tubing. A flame is conveyed by such tubing from the top of the gun to the bottom to ignite a booster charge which causes the detonation of the primer cord in the bottom section, which detonation moves upwardly through all the gun sections.

대표청구항 ▼

A perforating gun for a subterranean well, comprising: an elongated tubular carrier insertable in the well and defining a chamber normally sealed from entry of well fluids; a plurality of shaped charge containers transversely mounted in said carrier chamber in vertically spaced relation, each said s

A perforating gun for a subterranean well, comprising: an elongated tubular carrier insertable in the well and defining a chamber normally sealed from entry of well fluids; a plurality of shaped charge containers transversely mounted in said carrier chamber in vertically spaced relation, each said shaped charge container having a primer end and a discharge end; a firing mechanism including a primer charge disposed above said shaped charge containers; a booster charge disposed below said shaped charge containers in the bottom of said chamber to be rendered inoperable by well fluids entering said chamber; primer cord means for detonating said shaped charges extending upwardly from said booster charge to pass adjacent all primer ends of said shaped charge containers; and means responsive to detonation of said primer charge for detonating said bottom booster charge to ignite said primer cord means to successively fire said shaped charges from the bottom of the gun upwardly to the top. The method of detonating a plurality of vertically spaced shaped charges of a perforating gun for a subterranean well, comprising the steps of: (1) at the well surface connecting a booster charge below all of the shaped charged and a firing mechanism above all of the shaped charges; (2) connecting a detonation transmitting cord between the firing mechanism and the booster charge, said cord, when detonated, being incapable of detonating the shaped charges but capable of detonating the booster charge; (3) running a primer cord in close proximity to each of said shaped charges and into contact with said booster charge; said primer cord being detonatable by said booster charge and having sufficient energy to successively fire each of said shaped charges; and (4) lowering the perforating gun into the well to the desired location and actuating said firing mechanism, whereby said shaped charges are successively fired from the lowermost one upwardly.