油井重复压裂工艺技术研究

重复压裂工艺技术是低渗透油田增加单井产量，确保油田稳产，提高经济效益的关键手段。文中对长庆低渗透油田的产量递减因素进行了详细的分析，认为地层压力下降会引起孔隙度下降，含水饱和度上升。并结合近几年重复压裂工艺的现场实践，提出了重复压裂井的选井条件；（１）初次压裂规模小的井；（２）初次压裂失败的井；（３）初次压裂产生了伤害的井；（４）初次压裂工艺落后的井，如裂缝导流能力低；（５）地层压力保持在原始压力

Refracturing technology in Oil wells

The refracturing plays a very important role in increasing oil well production,stabilizing oil field productivity and improving the economic benefit of low permeability reservoirs.This paper analyzes in detail the reason that causes the production decline in Changqing Oilfield,and concluded that a drawdown of formation pressure might cause the porosity to decline and the water saturation to increase.Based on the field experience of refracturing technology in recent years,points out that the following kinds of well could be selected as candidates for refracturing①wells which are primarily fractured in a small scale;②wells which are failed during primary fractured stimulation;③wells which are damaged during first fracturing stimulation;④wells which are primarily fractured which backward techniques；⑤wells of who the formation pressure is still above 80% of the original pressure.