保德区块中低阶煤层压裂施工砂堵原因分析及技术对策

Causes Analysis and Technical Countermeasures of Sand Plug in Coal-bed Hydraulic Fracturing Construction in Baode Block

摘要:

针对保德区块中低阶煤储层压裂过程中容易出现砂堵影响储层改造效果的问题，根据研究区块的地质条件，结合水力压裂时裂缝在煤层中的扩展规律，分析了保德区块煤层水力压裂出现砂堵的4类主要原因，分别为煤储层裂隙相对发育造成压裂液滤失量增加、压裂沟通高渗透性的顶底板、煤储层本身有效厚度大滤失量增大及多层合压造缝不充分。在此基础上，提出了相应的技术对策，使用清洁压裂液、适当提高并稳定施工排量及优化压裂施工设计，为现场的水力压裂施工和提高煤储层改造效果提供重要指导。

Abstract:

Sand plug occurred in the fracturing process of low and middle rank coal reservoir in Baode block, which affected the reservoir reconstruction. Based on the geological features of this block, combined with the extension law of hydraulic fracturing in coal seams, the main factors caused sand plugging are analyzed, such as the increase of fracturing fluid loss caused by development of coal reservoir fractures and high permeability roof and floor fracturing and so on. The corresponding technical countermeasures are put forward on this basis, by using clean fracturing fluid, appropriately increasing and stabilizing the fracturing fluid displacement in construction and optimizing fracturing design, the reservoir reconstruction effect can be improved.