MECHANICAL PERFORATOR FOR DRILLING WALLS IN PIPE-CASED WELLS Russian patent published in 1998 - IPC

FIELD: oil and gas production industry. SUBSTANCE: this is used for perforation of oil, gas, and other wells which are cased off by pipes and it ensures creation of passages of large area and length in wall of well. It also makes for reliability and fail-safe operation. Device has double-step drilling head with drive from immersed motor, feed unit in the form of telescopic hydraulic cylinder, and return mechanism in the form of spring. In another version, return mechanism is located beyond feed unit. In this case it is provided with hydraulic automatics which at receiving required pressure performs disengagement of return mechanism - engagement of feed unit - drilling to required depth-disengagement of feed unit - engagement of return mechanism - return operation. This cuts hydraulic resistance in passages. Application of aforesaid embodiment of device adds to well output and minimizes probability of jamming drilling head in wall of well. EFFECT: higher efficiency. 2 cl, 3 dwg