【作者】 黎水泉；

【导师】 徐秉业；

【作者基本信息】 清华大学 ， 固体力学， 2000， 博士

【摘要】 一.从孔隙度及渗透率的基本定义出发,考虑骨架变形对孔隙度和渗透率的影响,建立了裂缝性双重孔隙介质孔隙度及渗透率与介质变形的关系,即应变孔隙度模型和应变渗透率模型。 二.考虑骨架变形与基质孔隙流体流动及裂隙流动的耦合效应,在传统多组分渗流模型的基础上,建立了双重孔隙介质多相多组分流体的流固耦合渗流理论模型。并在此基础上,经适当简化,得到了本文计算所用的双重孔隙介质三相流体流固耦合渗流模型。 三.首次将弹脆塑性应变软化本构模型引入裂缝性油藏储层介质变形描述。结合广义有效应力原理,并通过引入应力跌落时发生各向同性软化的假定,给出了用广义有效应力表述的弹脆塑性应变软化本构模型及其积分数值格式以及增量型弹脆塑性有限元求解算法。与裂缝性双重孔隙介质流固耦合多相流渗流模型及应变孔隙度模型、应变渗透率模型结合,从而首次建立了考虑弹脆塑性应变软化的裂缝性双重孔隙介质全耦合多相流流固耦合渗流模型。 四.独立开发了弹脆塑性应变软化裂缝性双重孔隙介质全耦合多相流流固耦合渗流的数值模拟有限元软件。算例对比结果显示,数值模型算法合理,程序计算结果准确可靠。 五.对一典型裂缝性油藏开采过程进行了数值模拟。结果表明,在具有弹脆塑性特性的裂缝性储层中,会形成弹脆塑性压实区,其渗流阻隔效应是导致生产压力和产量突变的主要因素。这些结果与生产实际中的现象相吻合。这表明弹脆塑性软化双重孔隙介质流固耦合模型能够更合理地解释裂缝性油藏生产过程中的压力和产量的变化特性,及裂缝性油藏压力敏感性机理。因此,对于裂缝性储层,尤其是弹脆塑性软化特征较明显及压力敏感性强的储层,应该考虑弹脆塑性压实区的形成及其渗流阻隔效应,应对油藏的流固耦合效应进行数值模拟,以更科学地制订裂缝性油藏开采方案。更多还原

【Abstract】 This paper worked out the fully coupled numerical simulation of naturally fractured reservoirs based on the dual porosity model.1. The relationships between the elasto-brittle-plastic strains of a fractured porous medium saturated with compressible fluids and its dual porosity, dual permeability have been given. This relationship is prior to the models, which relate the porosity, permeability with fluid pressures or effective stresses within the medium because the former can describe the comprehensive effect on porosity and permeability change and their unrecoverable behaviors.2. Based on the conventional multicomponent model, this paper presented a set of coupled governing equations for multicomponents, multiphase fluid flows within the fractured porous medium, which taking into account the interactive effect of soil deformation and fluid flows. After simplifying under conditions, the coupled flow governing equations for three-phase fluid & three components have been obtained.3. One kind of elasto-brittle-plastic constitutive model has been given and used to describe the fractured porous medium deformation. The corresponding incremental elasto-brittle-plastic finite element solution scheme has been proposed. Combining the generalized effective stress principle and the coupled multiphase fluid model, as well as new porosity model & permeability model proposed above, a new fully coupled mathematical model for multiphase fluid flow within fractured porous medium was developed. Considering the solid displacements and the fluid pressures as primary unknowns, the Galerkin-based finite element method was applied to discretize the governing equations both in space and time domain.4. The corresponding computer codes have been developed all alone.5. The computer program developed by author was be used to simulate a typical naturally fractured reservoir and to be verified. Based on the results of numerical simulation, some practical phenomena can be understood more clearly, and some constructive suggestions have been proposed.更多还原