低渗透油藏超裂缝延伸压力注水方法探讨

Super fracture extensional pressure water injection method of low permeability reservoir

低渗透油藏经压裂改造进入注水开发期后,由于井底注水压力已接近或超过裂缝延伸压力,在注水井中裂缝前缘可能会因微裂缝张开而逐步形成高渗透带。如果井网布置不当,裂缝处于不利方位,生产井将出现见水早、甚至暴性水淹等不利于生产的严重后果。为此,提出了一种新的井网布置方式,同时试图利用这类低渗透油藏超过裂缝延伸压力注水时裂缝前缘可能形成高渗透带的特性来减少注水井数,以提高低渗透油藏开发的整体经济效益。

When low permeability reservoir is developed into water flooding period through fraturing, for the modified reservoir, bottom hole water injection pressure is close to or more than fracture extensional pressure during the flood period, so high permeability zone are gradually forming in frontal fracture. If pattern arrangement is irrational, fracture is in adverse orientation, serious consequence such as early water breakthrough, even burst water flood will happen to producing well. Thus, this article puts forward a new kind of well pattern to avoid the adverse producing condition. At the same time, to decrease water injection well and enhance the whole economic benefit of low permeability reservoir development, the characteristics of low permeability reservoir have been tried to utilization.