缝洞型油藏试井新模型探讨

DISCUSSION ON NEW WELL TEST MODEL FOR FRACTURE-CAVITY RESERVOIR

对于目前某些油田存在大尺度的缝洞，其流动不符合达西定律的情况，建立了不同缝洞连通型试井新模型。给出了缝洞型油藏试井物理模型的描述，建立拟稳态情况下的流动方程，通过拉普拉斯变换对数学模型进行求解，并利用数值反演的方法得到实空间下不同试井模型的解，绘制了各类缝洞型油藏试井新模型的试井曲线，并对曲线特征和影响因素进行了分析。缝洞型试井曲线在早期段和晚期段都是斜率为1的直线段，中间段会出现和双重介质或三重介质相似的下凹段，下凹段出现早晚和下凹的深浅受缝洞间窜流系数和缝洞储容差异的影响。这类缝洞型新的试井模型研究，对具有缝洞特征性质油藏的试井解释有新的指导作用。

According to the large-size fracture-cavity reservoirs where fluid flow does not meet Darcy-flow law, new well test models and physical model of fracture-cavity reservoir with different communication types are established in this paper and pseudo-steady flowing equation is also built. Laplace transformation method is used to solve the mathematical model and the solutions of different well test modes in real space are obtained by means of numerical inversion method. The curves of new well test models are drawn for various fracture-cavity reservoirs and their curved characteristics and influencing factors are analyzed. Well test curves of fracture cavity reservoirs represent u- nit slope straight line with at early and late time regime. At the middle period, concave segment similar to double media or tri-media occurs, which is affected by interporosity flow coefficient and storativity difference of fracturecavity reservoirs. The study on well test model of fracture-cavity reservoirs provides new guidance for well test interpretation of fracture cavity reservoirs.