深层碳酸盐岩大斜度井及水平井纤维暂堵转向分段压裂参数优化

Optimization of Fracture Parameters for Staged Fracturing with Temporary Fiber Plugging and Diversion in Highly Deviated Wells and Horizontal Wells in Deep Carbonate Reservoirs

为进一步提高四川盆地高石梯-磨溪地区Ⅱ、Ⅲ类储层大斜度井及水平井分段压裂的段数,实现全井段压裂,通过开展室内暂堵转向分段压裂物理模拟实验优化分段压裂参数。研究表明:暂堵纤维质量分数及施工排量是影响转向效果的关键因素;纤维长度为3~12 mm的纤维组合,在质量分数为2.5%,排量为120~250 mL/min时,封堵压力达到限压15 MPa,形成稳定封堵且无突破。将研究结果应用于高石梯-磨溪地区Ⅱ、Ⅲ类储层大斜度井及水平井多级分段压裂,证实了该工艺技术的可行性,相比同类未实施分段压裂的储层,测试产量提高46%。该研究对促进碳酸盐岩中低品位资源的有效动用提供了借鉴。

To further increase the number of stages of staged fracturing and achieve full-well staged fracturing of highly deviated wells and horizontal wells in Types Ⅱ and Ⅲ reservoirs in Gaoshiti-Moxi Area,Sichuan Basin,a laboratory experiment was conducted for physical simulation of temporary plugging and turnaround staged fracturing to optimize staged fracturing parameters.The study showed that,the mass fraction of temporarily plugged fibers and the construction displacement are the key factors affecting the diversion effect;the plugging pressure reached the pressure limit of 15 MPa at a mass fraction of 2.5%and a displacement of 120-250 mL/min for fiber combinations with fiber length of 3-12 mm,forming a stable plug without breakout.The results of the study were applied to multi-stage fracturing of highly deviated wells and horizontal wells in Types Ⅱ and Ⅲ reservoirs,Gaoshiti-Maoxi Area,confirming the feasibility of the technology.The test production was increased by 46%compared to similar reservoirs where staged fracturing was not implemented.The study provides a reference for promoting the effective prediction of low-grade resources in carbonates.