大牛地气田多级注入酸压工艺优化研究与应用

页岩储层需要采用大排量、大液量体积压裂才能获得工业气流,体积压裂要求压裂液具有可连续混配、低摩阻和高返排率性能。根据四川页岩储层特征和实验结果,研制了降阻性能高的聚丙烯酰胺降阻剂、高效复合防膨剂及微乳助排剂,研制了适于四川页岩气体积压裂的滑溜水。该配方在四川W、C区块直井8井次现场试验表明,降阻率为65.5%～68.3%;W区块平均返排率为46.19%,C区块返排率27.93%;累计增加井口测试产量6.24×104～11.35×104 m3/d。

Research and application of the multiple injection acid fracturing technology in Daniudi gas field

The shale reservoir requires volume fracturing with large displacement and large a- mount of fluid in order to obtain industrial gas flow. According to the volume fracturing require- ment, the slick water should have low viscosity, low friction, high flowback, excellent antiswell- ing and good compatibility properties with reservoir. Combing the Sichuan reservoir characteris- tics with experimental result, we developed a polyacrylamide friction reducer, an efficient anti- swelling agent and microemulsion surfactant, and developed a liquid formulation fitting to Si- chuan shale reservoir. The field tests of 8 wells in Sichuan W and C blocks showed that the excel- lent performance of friction reduction, whose friction reduction rate is 65.5%oo to 68.3% ; the W block average flowback rate is 46. 19%, the C block average flowback rate is 27.93%, and the cumulative test production reach 6.24×10^411.35 ×10^4m3/d..