METHOD OF PERIODIC OPERATION OF MARGINAL WELLS BY DEEP-WELL PUMPING UNIT Russian patent published in 2002 - IPC

FIELD: oil production from marginal wells. SUBSTANCE: method includes alternating of fluid accumulation cycle and fluid pumping out of well provided with sump. According to the invention, minimum permissible bottom-hole pressure and annulus pressure corresponding to minimum permissible bottom-hole pressure are determined with consideration of value of permissible differential pressure on formation corresponding to maximum permissible well productivity and to conditions of formation preservation. During processes of accumulation and pumping out of fluid from well, annulus pressure is monitored. If its value rises in process of accumulation and drops in process of pumping out, gas is bled off from annulus, or gas is injected into annulus, respectively. This is effected for maintaining the annulus pressure at definite value and restoration in both cases of selected value of working differential pressure on formation. EFFECT: maximum productivity of well. 4 dwg, 1 ex