【作者】 冯金德；

【导师】 程林松；

【作者基本信息】 中国石油大学（北京） ， 油气田开发工程， 2007， 博士

【摘要】 针对裂缝性低渗透油藏物性差、天然裂缝发育,难以建立有效驱替压力系统的难题,采用物理模拟、理论研究及数值模拟的方法,将天然裂缝表征成果应用到油藏工程研究中,研究了这类油藏复杂的非线性渗流规律和建立有效驱替压力系统以及改善开发效果的方法。首先,用电模拟实验研究了不同类型井网、井型条件下的井网渗流场特征及产能变化规律,优选出有利于建立有效驱替压力系统和提高单井产量的井网和井型;定量研究了天然裂缝与人工裂缝以及水平井耦合作用对不同类型井网渗流场及产能的影响;提出新的电模拟实验设计方法,研究了各向异性储层井网渗流场特征和产能,为井网与天然裂缝的合理匹配及井型的选择奠定了基础。在裂缝岩心应力敏感实验中,采用油测回压控制的内压加压法,在更接近油藏多孔介质受力条件的情况下研究了含裂缝岩心的应力敏感性,并与常规的气测围压法结果进行了对比分析。其次,建立了裂缝性非均质复合油藏渗流模型,研究了天然裂缝表征参数对压力、产量的影响规律,从理论上解释了天然裂缝的增产机理。利用张量理论和等效连续介质理论,将复杂的天然裂缝系统简化,建立了裂缝性低渗透油藏的等效连续介质模型,使裂缝识别表征成果同油藏工程研究较好地结合起来。在储层等效连续介质模型的基础上,研究了单井不稳定渗流及多井井间干扰不稳定渗流的渗流规律,探讨了确定井网技术极限井距、排距的方法;考虑人工裂缝和水平段的方向同天然裂缝发育方向的相对关系,推导出裂缝各向异性油藏中直井与压裂直井、直井与水平井联合井网及水平井井网的产能公式;研究了井网优化方法,为井网参数的确定提供了理论依据。再次,考虑天然裂缝表征参数及油水两相启动压力梯度,利用张量理论及相关渗流力学理论,建立了裂缝性低渗透油藏的三维三相渗流数学模型,用数值方法进行求解,编制了相应的数值模拟软件。研究了裂缝性低渗透油藏中复杂条件下的渗流规律。最后,考虑天然裂缝影响,进行了井网、井网参数及注水方式优化数值模拟应用研究。研究成果对指导裂缝性低渗透油藏开发具有重要的现实意义。更多还原

【Abstract】 It is difficult to establish an effective flooding pressure system for fractured low permeability reservoir because of developed fractures and very low permeability. Applied the fracture characterization parameters to reservoir researches, and adopted method of experiment, theoretical analysis and reservoir simulation, the laws of nonlinear percolation and development methods of these sort of reservoirs are studied.First, by a great deal of electric-analogy-modeling experiments, percolation field and productivity of well patterns under conditions of without natural fractures, as well as coupling between natural fracture and hydraulics fracture are quantificationally studied; and a new electric-analogy-modeling method is developed, by this method, percolation field and productivity of well patterns in anisotropy reservoir can be studied. These results provide foundation for optimization of well type and well pattern, which matches with natural fractures. In experiments of stress sensitivity of fractured cores, an improved method is designed to study fractured cores under force condition much closer to the reservoir condition. At the same time, the usual stress sensitivity experimental method is used, and the results of these two methods are compared and analyzed.Second, a fractured heterogeneity composite reservoir model is established, and influences of natural fracture parameters on pressure and productivity are studied. An equivalent continuous medium model of fractured low permeability reservoir is established by using tensor theory and equivalent continuous medium theory. This model combines the results of natural fracture identification and characterization with reservoir engineering research, which provides a basis to nonlinear percolation theory of fractured low permeability. Based on this model, considering start-up pressure gradient, the unsteady state flow laws of single well and inter-well interference are studied; the approaches of determining critical well spacing and critical row spacing are put forward. Considering the directions of hydraulics fracture and horizontal segment of horizontal well relatively to natural fracture orientation, the productivity equations of combined well pattern of horizontal and vertical wells, hydraulics fractured well and vertical wells, as well as well pattern of horizontal wells, are deduced respectively, and optimization methods of well pattern are given.Third, taking natural fracture parameters and start-up pressure gradient of both water phase and oil phase into account, by means of tensor theory and related percolation theory,a three dimensions and three phases percolation mathematical model of fractured low permeability reservoir is established. This model is solved by numerical method, and corresponding numerical simulation software is developed. The flow laws under complex conditions in fractured low permeability are studied by this software.Finally, considering effect of natural fractures, the well pattern type, well pattern parameters and flooding patterns are studied by numerical simulation.The research above is useful to the reasonable development of fractured low permeability reservoirs.更多还原