水力压裂裂缝模拟研究

针对低渗油气藏水力压裂裂缝通常采用直角网格加密模拟准确性不高的问题,采用了油藏数值模拟中的新型网格结构——PEBI网格来模拟水力裂缝.在充分认识水力裂缝渗流机理的基础上,深入分析了数值模拟中处理水力裂缝的常规直角网格加密方法和PEBI网格方法的原理;并以某火山岩油藏为例运用两种方法对裂缝方位、导流能力和裂缝穿透比进行优化研究.研究结果表明,PEBI网格模拟水力裂缝的方法相对于常规直角网格加密方法具有较高的准确性和优越性.运用该方法可以为现场压裂施工设计和效果评价提供一种有效的研究手段,对于提高低渗油气藏压裂效果具有实际意义.

Study on the simulation of hydraulic fracturing cracks

The accuracy of simulation of the hydraulic fracturing cracks in low-permeability reservoirs using Cartesian grid encrypting is low,and so PEBI grid encrypting generally used in reservoir simulation is used in the simulation of the hydraulic cracks of low-permeability reservoirs.On the basis of understanding the seepage mechanism of hydraulic fractures,the principles of Cartesian grid encrypting method and PEBI grid encrypting method are analyzed.And as an example,the fracture azimuth,flow conductivity and penetration ratio of some volcanic reservoir are optimized using Cartesian grid encrypting method and PEBI grid encrypting method separately.The results show that PEBI grid encrypting method has higher accuracy than Cartesian grid encrypting method for the simulation of the hydrocarbon cracks.The PEBI grid encrypting method can provide a effective research means for the design of field fracturing construction and the evaluation of the fracturing results,and it is of practical significance to improving the fracturing result of low-permeability reservoirs.