苏里格气田下二叠统储层改造难点及对策

Technical difficulties and countermeasures for hydraulic fracturing in lower Permian gas reservoirs of the Sulige gas field

苏里格气田储层具有"低孔、低渗、低压"的特点,水力压裂改造成为开发该气田的主要手段。由于储层物性变化大、多薄层等原因,单井压裂改造裂缝参数在井网中效应的优化难度很大,施工参数很难考虑地应力剖面的纵向控制效果。因此,针对压裂改造中的突出难点,提出了相应的解决对策:建立单井与井网匹配优化模型,充分利用数值模拟、裂缝参数优化、应力剖面分析技术和裂缝闭合优化等技术。应用上述配套技术,使得压裂改造的裂缝参数与储层的匹配更加紧密;根据应力特征优化的参数更有针对性,有利于获得合理裂缝剖面;利用所提出的小型压裂技术进一步增强了对储层的认识和对压裂工艺的提升。为苏里格气田的储层改造和压裂效果的评估提供了技术支持。

The Sulige gas field is characterized by low porosity,low permeability and low pressure,so hydraulic fracturing is one of the main measures to enhance the gas recovery of this gas field.Because of the strong heterogeneity of petrophysical property of reservoirs and multiple thin layers,it is difficult to optimize the effects of fracture parameters during a single well's fracturing in the whole well pattern and operating parameters can hardly represent the control effect of in-situ stress profile to fracture vertical extension.To solve these problems,an optimization model of single well matched with the well pattern was built and several appropriate countermeasures were given by using numerical simulation,fracture parameter optimization,the stress profile analysis and fracture closure technique.The optimized treatment parameters according to the stress characteristics and mini-frac test can be favor of getting reasonable fracture geometry and getting more reservoir information to improve fracturing technology,which can help improve the reservoir stimulation techniques and post-fracturing evaluation of the Sulige gas field.