砂岩储层裂缝宽度预测新方法

NEW METHOD FOR PREDICTION OF WIDTH OF FRACTURES IN SANDSTONE RESERVOIRS

对于裂缝-孔隙性双重介质油气藏来说,由于其特殊的储层结构,使常规储层保护方法受到很大的限制,特别是对于川西地区的裂缝性致密砂岩气藏,对其进行合理的储层保护显得更加必要。通过对裂缝表面光电扫描及计算机成象分析系统对裂缝表面进行了精细描述和分析,对裂缝-孔隙型砂岩储层裂缝的应力敏感特征进行了计算机模拟和实验研究;提出了裂缝宽度预测模型;运用张量理论,在裂缝空间分布的定量描述和裂缝闭合特性的计算机模拟的基础上,结合储层的应力分布,得到了计算储层裂缝张量的应力敏感模型。运用上述结果对川西新场气田砂岩储层的裂缝宽度进行预测,为完井液配方的设计和筛选提供依据。

The special structure of fracture-pore hydrocarbon reservoirs makes conventional reservoir protection methods limited greatly,especially in dense sand gas reservoirs in western Sichuan.It is necessary to protect the reservoirs reasonably.Through delicate description and analysis of fracture surface by an optoelectronic scanning and imaging system,the stress sensitivity characteristics of fractures in fracture-pore sandstone reservoirs are simulated by computers and studied in experiments.A model for width of fracture prediction is put forward.Then a stress sensitivity model is obtained to calculate reservoir fracture tensor on the basis of quantitative description of fracture spatilal distribution and characteristic simulation of fracture closure with combination of reservoir stress distribution.It has provided basis for design and filtration of completion fluid formulation in Xinchang gas field of western Sichuan.