低渗透变形介质油藏流入动态关系

Inflow performance relationship for low permeability & deformed media reservoir

针对已有低渗透油藏流入动态关系偏重于分析启动压力对产能影响以及某些关系式仅适用于弱应力敏感性的现状,建立适用于微裂缝发育或人工压裂缝等考虑强应力敏感性的无因次流入动态通式。在无因次流入动态影响因素的敏感性分析中,克服常规分析中固定目标影响因素外所有参数的静态处理缺陷,对储层变形系数与目标影响因素进行动态组合分析。结果表明:随变形系数由零转变为非零值并逐渐增大,流入动态曲线由抛物线型向S型转变,储层压敏效应对产能影响趋于显著;主要影响因素敏感性由高到低一般为启动压力、地层平均压力、污染程度、供给半径,但在不同的流压和产量区间,影响因素敏感性排序并非固定不变,而且每个影响因素自身也存在不同的敏感性变化区间。

With respect to existing inflow performance relationship（IPR） for low permeability reservoirs emphasizing the effect of start-up pressure on productivity and some formula applying only to weak stress sensitivity,a non-dimensional inflow performance relationship considering strong stress sensitivity suitable for micro-fracture development or artificial pressure crack was established.In the sensitivity analysis of non-dimensional inflow performance influence factors,static processing defects of the routine analyzing were overcome,that is to say,all influencing factors were fixed outside target parameters.The dynamic combination analysis of reservoir distortion coefficient and target influencing factors was done.The results show that the type of IPR curve transfers ＂S＂ type from parabola one when the deformed factor gradually increases from zero to non-zero,the stress-sensitivity of reservoir can obviously affect productivity with evidence.The sensitivity degree of influencing factors from strong to weak is start-up pressure,average formation pressure,damage degree,drainage radius,but the sensitivity rank may change in different flow pressure region and production region.Also,each factor affecting the IPR curve exists differently sensitive scope itself.