基于非达西、压敏效应及裂缝的数模技术

NUMERICAL SIMULATION TECHNIQES ON THE BASES OF NON-DARCY AND PRESSURE-SENSITIVITY AND FRACTURES

针对工程化数模软件不能准确描述低渗透油藏非达西渗流特征问题,建立了同时考虑特低渗透油藏流体非达西渗流和变形介质的数学模型,建立了势梯度模合成方法,完善了井和网格方程耦合技术,在自主裂缝数值模拟软件上开发了低渗透油藏流体非达西渗流、压敏效应功能,推出了集非达西、压敏效应、裂缝功能于一体的DQdual2.0软件。实际算例分析表明,非达西渗流模式反映了启动压力的存在,能较真实地模拟低渗透储层的产油能力。大庆油田10个区块应用结果表明,DQdual2.0软件适用于低渗透油田开发动态计算。

In the light of the problem that the engineering numerical simulating software cannot describe the fluid seepage characteristics of low-permeability oil reservoirs accurately,the mathematical model is established,in which non-Darcy seepage flow and deformed media are synchronously considered,and then the modular composing method of the potential gradients is developed,the coupling technique of the wells and grid equations are all improved.Based on the self-developed numerical simulating software for the fractures,the functions of non-Darcy seepage flow and pressure-sensitive effect are presented for the low-permeability oil reservoirs,and moreover DQdual 2.0 Software integrating non-Darcy seepage flow,pressure sensitivity and fracture functions is developed.The analyses of the history cases show that the non-Darcy seepage flow mode has reflected the existing of the starting pressure and furthermore can simulates the productivity of the low-permeability oil reservoirs more actually.The applied results of the software in the ten blocks of Daqing Oilfield prove that it is feasible to the calculation of the lowpermeability oilfield development performances.