四川盆地低渗透砂岩气藏大型水力加砂压裂配套技术

A matching technology of hydraulic sand fracturing on a large scale for low-permeability sand gas reservoirs in the Sichuan Basin

增产改造是低渗透砂岩气藏开发效果的重要保障手段,为了提高气藏单井产量,实现效益开发,中国石油西南油气田公司在该领域开展了广泛深入的研究,形成了以大型水力加砂压裂为主的储层改造及其配套技术,包括:气藏整体压裂方案设计技术,以微型注入为主的压前评价技术,以数值模拟、节点分析为主的大型压裂优化设计技术,以差应变、声发射、黏滞剩磁室内实验与测井资料相结合的地应力大小及方向的分析技术,以示踪迹、微地震为主的裂缝形态监测技术等。这些配套技术的形成,使大型水力加砂压裂工艺在试验区内取得了显著的增产效果,为川渝气区大力推进盆地内砂岩气藏的勘探开发奠定了基础。这些关键技术的研究、归纳与总结,为低渗透砂岩气藏的规模化、效益化开发提供了技术支持。

Stimulation treatment is an important guarantee of means for exploiting the low-permeability sandstone gas reservoirs. In order to improve the productivity of each individual well and obtain beneficial exploitation, the PetroChina Southwest Oil and Gasfield Company has carried out in-depth and extensive studies on this field and finally formed its expertise in reservoir reconstruction and its matching technologies in hydraulic sand fracturing on a large scale, which includes integral planning of fracturing on gas reservoirs, the pre-frac evaluation dominated by mini-injection pressure analysis, the large-scale hydraulic fracturing optimization and design which involve numerical simulation and nodal analysis. In-situ stress value and direction analysis techniques which are associated with well logging data and the experimental data of difference strain analysis and acoustic emission and viscous remanent magnetization, and fracture monitoring mainly including the tracing and microseismic wave method. With these techniques, good results have been achieved in large-scale hydraulic sand fracturing in pilot test fields, providing a robust foundation for the exploration and development of sandstone gas reservoirs within the Sichuan Basin. This study and applications of the above-mentioned techniques provide technical support for the company to exploit low-permeability sand gas reservoirs commercially and profitably in the Sichuan Basin.