水基压裂液对储层伤害性研究

通过室内实验,测定了4种类型压裂液(羟丙基胍胶型压裂液、田菁胶型压裂液、香豆胶型压裂液、胍胶原粉型压裂液)的性能,评价了压裂液与模拟延长川口采油厂储层岩石和地层水的相容性,并对模拟长6油层岩心进行了五类敏感性的分析,找出了压裂液对储层伤害的原因,为改善本油层使用压裂液性能提供依据。实验结果表明,4种类型压裂液的残渣量均较大,是造成压裂低效的主要原因;压裂液中破胶剂浓度相同的情况下,破胶时间与温度成反比,胶囊破胶剂有相对较高的降粘率;长6油层具有较强的水敏性、中度酸敏性和碱敏性,且压裂液对岩心渗透率损害严重。

The study of reservoir damage due to water base fracturing fluid

Based on experiments,the mass concentration and gel breaking rate of four fracturing fluids(velocity sensitivity,salinity sensitivity,water sensitivity,acid sensitivity and alkali sensitivities)were determined,and the compatibility of these fracturing fluid with the simulative core and formation water of Chuankou reservior in Yanchang oilfield were evaluated,several sensitivities of Chang-6 reservior core were analyzed.By discovering the main reasons why the fracturing fluid contaminated formation,an important basis for improving the performance of fracturing fluid was presented.The results of experiment showed that the residual mass of four fracturing fluids were excessive,which was the important basis for improving the performance of fracturing fluid;the time of gel breaking is inverse ratio with temperature in the same concentration of gel breaker,and capsular gel breaker had higher rate of viscosity-reducing comparative;there were strong water sensitivity,moderate acid sensitivity and alkali sensitivities,which led to strong damage to the core.