强变形暂堵转向压裂技术研究及应用

南堡x号构造火山碎屑岩天然裂缝发育，有利于复杂裂缝构建和提高体积压裂效果。针对暂堵转向压裂中暂堵不明显，有效性低的问题，优化暂堵材料，引入有机硅单体，胶束聚合了一种强变形凝胶，通过剪切、造粒、烘干和粉碎后得到不同粒径强变形可膨胀缝口（缝内）暂堵剂，并通过缩合反应，粉末型缝内暂堵剂在高温下自动固化成滤饼，提高缝内暂堵的可行性。通过室内实验优化得到簇间暂堵剂配比:变形粒子（5～6 mm）∶纤维∶粉末（100～200目）=5∶1∶1，最高突破压力为56.3 MPa，变形粒子具有可吸水膨胀和强弹性的优良特征，从而大幅提高应力转向的可能性；缝内暂堵剂为微米级的粉末，最高封堵强度达54 MPa。该体系成功试验于火山岩油气藏，不采用专用车组，未影响泵效和出现卡泵现象，现场顺利泵送，施工成功率达100%。试验井簇间暂堵升压明显，平均提高4～16 MPa，缝内暂堵平均升压2～4 MPa，通过压裂施工曲线和微地震监测表明暂堵转向有效性高。 

Study and Application of Self-diverting Fracturing Fluid Containing Highly Deformable Temporary Plugging Agents

The natural fractures abundantly developed in the pyroclastic rocks in the Nanpu No. x structure are conducive to the construction of complex fractures and the improvement of the effect of stimulated reservoir volume fracturing. In previous self-diverting temporary plugging fracturing operation, the effect of temporary plugging has been unsatisfactory. To resolve this problem, the temporary plugging agent was optimized using silicone monomer which forms a highly deformable gel through micellar polymerization. The gel, after shearing, granulating, drying and pulverizing was turned into highly deformable expandable temporary plugging agent of different particle sizes to temporarily plug the mouth (inside) of fractures. This pulverized temporary plugging agent can automatically solidify at elevated temperatures to form a filter cake through condensation, thereby improving the effect of temporary plugging inside the fractures. The optimum ratio of different particles in the final plugging agent formulation (between two well clusters) through laboratory experiment is: deformable particle (5 – 6 mm) ∶ fiber ∶ powder (100 – 200 mesh) = 5∶1∶1, and the highest breakthrough pressure of this temporary plugging agent is 56.3 MPa. The deformable particles in the temporary plugging agent can expand after absorbing water, and has good elasticity, which greatly increase the likelihood of stress diversion. This temporary plugging agent, a nanometer powdered product, can produce a plugging barrier withstanding a pressure of up to 54 MPa. The temporary plugging agent has been used in the operation in volcanic rock reservoirs without the need of special fracturing trucks. The temporary plugging agent did not affect the pump efficiency, and pumps did not get stuck during field operation. The success rate of the temporary plugging agent was 100%. Pressure increases because of temporary plugging between two well clusters are obvious, averaged between 4 and 16 MPa. The pressure increases inside the fractures because of the temporary plugging were 2 – 4 MPa in average. Fracturing curves of field operation and micro-seismic monitoring showed that the diverting efficiency was high.