低渗透油田重复压裂蜡球暂堵剂性能研究

安塞低渗透油田受天然微裂缝发育的影响，人工裂缝的侧向油井见效差，油藏产量和压力分布严重不均，部分区块长期不见效，油井处于低产低效状态。重复压裂改造是否成功的关键在于能否构建新的裂缝系统。作为堵老缝压新缝的堵剂，对其性能要求：在一定温度下软化且在一定压力下易变形，即能与老裂缝中的残留固相、压裂液中的支撑剂一起形成理想封堵；有良好的粘弹性，与原油配伍好，残余在缝中的暂堵剂易返排，保证泄油通道畅通。本文通过热稳定性测试实验、与原油配伍实验、压力模拟实验、溶解速度实验及封堵与返排实验，研制并论证了油溶性蜡球粒子暂堵剂对于低渗透油田重复压裂可有效地达到上述性能要求。

STUDY ON THE PERFORMANCE OF WAX-BEAD TEMPORARY BLOCKING AGENT USED FOR REFRACTURING IN LOW-PERMEABILITY RESERVOIR

By natural fracture effect, the output of side oil wells of artificial fracture in Ansai low- permeability oilfield is poor and production rate and pressure distribution are very unbalanced, some oil wells get off to the state of low yield. The success of refracturing depends on the new fracture system. As the blockage agent used to blockade old fractures to open new ones, its performances should be transformable in definite pressure, has good viscoelasticity, good compatibleness with crude oil, and the residual component in fracture should be easily returned to form expedite channels. By the experiments of thermal stability, oil-matching capacity, pressure simulation, solution rate, blockage and returning, the oil-soluble wax granule temporary blocking agent is developed and demonstrated it can reach above-mentioned performance requirements for refracturing in low- permeability oilfield.