DIRECTED-ENERGY FRACTURE FOR UNCONVENTIONAL GAS RECOVERY

MOST EFFORTS TO INCREASE PRODUCTION FROM UNCONVENTIONAL GAS RESOURCES IN THE UNITED STATES REQUIRE SOME FORM OF WELLBOREOR FORMATION FRACTURING TO INCREASE THE FLOW OF GAS TO THE WELLS. BOTH EXPLOSIVE AND HYDRAULIC FRACTURING TECHNIQUES HAVE BEEN USED WITH SUCCESS IN THE STIMULATION OF UNCONVENTIONAL GAS WELLS. BECAUSE OF THE UNUSUALLY LOW PERMEABILITIES OF UNCONVENTIONAL RESERVOIRS, AND THE FACT THAT THEIR PRODUCTION IS CONTROLLED BY NATURAL FRACTURES AND/OR LENTICULAR STRUCTURES, THERE IS CONSIDERABLE INTERESTIN DEVELOPING NOVEL WELL DRILLING, FRACTURING, AND COMPLETION TECHNIQUES SPECIALLY TAILORED TO THEIR PRODUCTION CHARACTERISTICS. WELL STIMULATION METHODS ARE REQUIRED THAT ARE PARTICULARLY APPLICABLE TO THE TREATMENT OF NATURALLY FRACTURED RESERVOIRS OR ARE SUITABLE FOR USE IN DIRECTIONALLY DRILLED HOLES. ONE PROMISING STIMULATION METHOD, UTILIZING GAS REFLECTION DYNAMICS WITH THE DETONATION OF CONVENTIONAL EXPLOSIVES, HAS FOUND CONSIDERABLE SUCCESS AND APPLICATION IN STRIPPER OIL WELL STIMULATION. THIS METHOD, WHILE OFFERING EXCELLENT FRACTURING POTENTIAL, HAS HERETOFORE BEEN LIMITED BY EXCESSIVE WELLBORE DAMAGE AND THE GENERATION OF FRACTURE PLUGGING FINES. TWO UNRELATED TECHNOLOGIES COULD BE COMBINED WITH THE GAS REFLECTION TECHNIQUES TO OVERCOME THESE LIMITATIONS. THE USE OF EXPLOSIVE CHARGE LINERS, DEVELOPED FOR FRACTURE CONTROLLED BLASTING APPLICATIONS, AND OF LOW-VELOCITY EXPLOSIVES DEVELOPED FOR FAIRLY CONVENTIONAL WELL SHOOTING COULD ELIMINATE THE WELLBORE DAMAGE AND FINES GENERATION PROBLEMS. THE INTEGRATED TECHNIQUE UNDER INVESTIGATION WOULD OFFER A DIRECTED, HIGH ENERGY GAS FRACTURING METHOD UNIQUELY SUITABLE FOR USE IN FRACTURED RESERVOIRS AND/OR DEVIATED HOLES.