致密油藏多重介质非线性渗流压力响应分析

为了达到高效开发致密油藏的目的,通过分析致密油藏的介质特点及渗流规律,建立了致密油藏多重介质数学模型,运用牛顿-拉普生迭代法求得了模型的数值解,验证了模型的正确性.分别研究了非线性渗流参数、窜流系数、弹性储容比、边界条件对试井曲线的影响.结果表明,非线性渗流特征主要影响了裂缝与基质之间的物质交换,当大裂缝与小裂缝、大裂缝与基质之间的窜流能力相同时,压力导数曲线上仅出现一个凹子;当窜流能力不同时,压力导数曲线上将会出现两个凹子.基质储容比的增加会同时导致两个凹子深度的增加,而微裂缝储容比的增加仅仅加大了第一个凹子的深度.

Pressure analysis of nonlinear flow in multiple media of tight oil reservoir

In order to realize the efficient development of the tight oil reservoirs, the multi-media mathematical model of multiple media tight oil reservoir is established on basis of flow equation analysis. The numerical solution of the model is obtained by the Newton-Raphson iteration method, which is used for the validation of the model. Then, the effects of nonlinear flow parameter, cross flow coefficient, elastic storativity ratio, and boundary conditions on well test curves are studied, respectively. Results show that the nonlinear seepage characteristic mainly affects the material exchange between fracture and matrix. When the cross flow ability between large-small fracture and large fracture-matrix is the same, there is only one caviton on the pressure derivative curve. Otherwise, there will be two cavitons. The increase of matrix storativity ratio lead to the increase of the depth of the two concavities at the same time, but the increase of micro fracture storativity ratio only increases the depth of the first caviton.