초록 ▼

An improvement in an apparatus for fracturing subterranean formation by explosive fracture wherein opposed end charges are detonated to enhance the explosive capability of a central charge, the improvement comprising intermediate driver charges intermediate the central charge in each of the respecti

An improvement in an apparatus for fracturing subterranean formation by explosive fracture wherein opposed end charges are detonated to enhance the explosive capability of a central charge, the improvement comprising intermediate driver charges intermediate the central charge in each of the respective end charges; the driver charges being detonated by the end charges to provide a sustained pressure wave for enhancing the rubblizing and fracturing of the subterranean formation and extend the fracture more deeply into the subterranean formation. Also disclosed are improved apparatus enabling carrying out the split second detonating of the respective explosive charges, containing the explosive charges without entangling cable and the like downhole and preventing misfiring.

대표청구항 ▼

In apparatus for fracturing a subterranean formation, including: a. elongate casing having a center and two ends; b. opposed end charges disposed at each end of said casing and adapted to direct respective explosions toward said center; and c. A central charge disposed at said center and adapted to

In apparatus for fracturing a subterranean formation, including: a. elongate casing having a center and two ends; b. opposed end charges disposed at each end of said casing and adapted to direct respective explosions toward said center; and c. A central charge disposed at said center and adapted to create a central zone of high pressure upon detonation; the improvement comprising: d. having said central charge being substantially centrally located along the axial length of said casing and said end charges for creating a central area of high pressure upon detonation; e. having each of said end charges adapted to direct an explosive force inwardly to contain the explosion of said center charge and to detonate an intermediate charge; f. a pair of intermediate charges disposed respectively between said central charge and each of said end charges, said intermediate charges comprising elongate driver for enhancing and sustaining the exceptionally high pressure generated by the combination of said central charge explosion and said end charge explosions for propagating a fracture more deeply into said subterranean formation; and g. respective detonating means for exploding respectively said central charge and substantially immediately thereafter said end charges such that said end charges detonate said intermediate charges and enhance the centrally located explosion to enlarge the fractured area in said subterranean formation and extend said fracture more deeply into said subterranean formation.