METHOD FOR THERMODYNAMIC PERFORATION OF THE CASED WELL AND DEVICE FOR IMPLEMENTING THE SAME Russian patent published in 1997 - IPC

FIELD: well drilling. SUBSTANCE: nozzle-provided unit with combustion chamber solid fuel charge is used. The charge of solid fuel is burned to produce super-sound high-temperature gaseous jet. The jet is guided to the obstacle and the perforation is carried out by erosion to form a cavern in casing string wall, drill string-borehole annulus cement stone, and productive rock. A passage of hydrodynamic coupling is provided though the cavern between the well and the productive rock. Than the cavern surface is cleaned by blowing. Than porous filtering coating is applied to this surface. As this takes place, perforation, cavern blowing, and applying the filtering coating are carried out on the base of different compositions of combustion products after burning solid fuel charge. The conditions of temperature and blowing down of the combustion products are changed. The device for thermodynamic perforation of the cased well includes a casing, combustible chamber with a charge of solid fuel placed in it, nozzle unit and ignition initiator. The device has an insertion piece placed between the charge of solid fuel and nozzle unit. It is made so as to be revolved stabilize the jet of the combustion products. A pressure down plank is there to stop the device to the casing string. The pressure down plank is made in the form of a cylinder with differential piston. Over-the-piston cavity includes a layer with erosion additions, a layer with additions for blowing off and a layer with additions of porous filtering coating. They are made so as to be burnt subsequently. The device has outer armoring thimble. The thimble is installed in the casing with a gap filled with viscous compound. Outer surfaces of the nozzle unit and combustion chamber have protective reflecting screen. EFFECT: higher efficiency. 4 cl, 8 dwg