【作者】 康成学；

【导师】 朱建伟；

【作者基本信息】 吉林大学 ， 矿产普查与勘探， 2014， 博士

【摘要】 朝鲜西朝鲜湾盆地是位于中朝板块东部隆起背景之上的一个中、新生代沉积盆地。因为该盆地经过了复杂的地质演化过程，所以盆地内发育多套沉积，属于多期发育、复合叠加、后期改造的特殊盆地。朝鲜西朝鲜湾盆地是晚中生代和早新生代形成于朝鲜和中国东部减薄陆壳上的一系列NE-SW向裂谷盆地中的一个，面积大约2000km2。西朝鲜湾盆地是朝鲜重要的含油气盆地之一。至今，朝鲜在该盆地作了大量的油气勘探工作，并已在西朝鲜湾盆地中生代地层钻井证实具有工业性油气流。朝鲜西朝鲜湾盆地（简称WKB）为中生界含油气储集层，由于储层经历了较长的构造作用，因此其孔隙结构类型多、混杂。不仅仅是其孔隙性和渗透能力较差，而且具有倾角，属于中孔隙、细喉道低渗透储层，因此常规的达西定律已不适用。要开发好低渗透油田，应正确认识其储层特征和渗流规律，正确的进行渗流力学计算，确定合理的开发方案。随着现代石油工业的发展，低渗透油田的开发越来越被人们所关注。与常规的中、高渗透油藏比起来，低渗透油藏具有明显的渗流特征：一是，流体渗流规律不符合经典的达西定律；二是，流体渗流中存在启动压力梯度，并且重力影响不可忽略。本文以朝鲜西朝鲜湾盆地中生界低渗透储层为研究对象，通过选取实际样品室内实验研究，给定了其储层的微观孔隙结构特征，在丰富调研的基础上，同时考虑启动压力梯度和重力影响时，进行了西朝鲜湾盆地低渗透油藏数值模拟方法研究。主要研究内容如下：1．应用压汞法西朝鲜湾盆地中生界低渗储层微观孔隙结构特征研究储层孔隙结构及物性研究在油气田开发及实践中具有重要的理论与实际意义。分析毛细管压力资料是评价储集层孔隙结构最直接有效的方法。压汞曲线在双对数坐标系中近似于双曲线。压汞测试一直是储集层孔隙结构研究的重要手段。本文根据朝鲜西朝鲜湾盆地下白垩统和上侏罗统储层的物性和压汞毛细管压力资料对该储层微观孔隙结构特征进行分析研究，并对储层进行划分，为该储层的进一步合理开发提供可靠的地质基础资料。2．考虑启动压力梯度和重力影响的相对渗透率计算公式推导及应用迄今为止，在油气田开发方面上，油、水、气相渗流的相对渗透率曲线是能够合理地开发油气田的重要指标之一。从渗流机理上讲，储层和流体的主要物理化学性质，如渗透率和孔隙结构、粘度和各相流度比，以及岩石表面润湿性和原油边界层厚度等，在相渗透率曲线中都能反映出来，而各相渗透率曲线的特点也反应了不同类型储层的水驱油特征和效果。在实践上，所使用的相对渗透率一般是通过室内驱替实验得到的。在相对渗透率的室内测量过程中，一直利用两种方法，即“稳态方法”和“非稳态方法”。目前广泛地所用的JBN法只是考虑启动压力梯度的影响，但是没有考虑重力影响，因此存在一定的局限性。本文利用传统的相对渗透率计算方法（JBN方法），推导出了同时考虑启动压力梯度和地层倾角的条件下计算油、水两相相对渗透率的方法，编制了相应的实用软件，并以朝鲜西朝鲜湾盆地中生界低渗含油气储层的油、水两相相对渗透率计算为实例进行应用说明。3．考虑启动压力梯度和重力影响的低渗透储层油水两相渗流模型建立及数值模拟在考虑启动压力梯度和重力影响的低渗透储层油水两相非线性渗流模型基础上，建立了低渗透油藏一维油水两相非线性渗流数学模型，构造了相应的有限差分离散化格式和非规则网格系统，给出了一维低渗透油藏两相非线性渗流数值模型。另外，根据该数学模型、数值模型，利用IMPES方法进行数值求解方法，并编制了相应的计算程序。本文将应用不同定解条件下的这些计算程序对一维低渗储层油水两相非线性渗流问题进行模拟计算，分析了模拟计算结果，并将该计算程序的模拟结果与实际开发动态进行比较，验证了模型与计算程序的正确性。研究表明地层斜度对低渗透油藏开发动态的影响较明显。更多还原

【Abstract】 The West Korea Bay（WKB） basin is located on Mesozoic-Cenozoic sedimentarybasin on the eastern China-Korea plate uplift background, and has experienced complexevolution process. It develops many sets of deposition, and belongs to special basin ofmulti stage, overlapping, and reformation.The WKB basin is one of a series of NE-SW rift basin formed in late Mesozoic andearly Cenozoic on thin continental crust of Korea and Eastern Chinese, its area is about2000km2.The WKB basin is one of the important petroliferous basins in Korea. Korea in thisbasin has made a lot of oil and gas exploration, and has confirmed existence of industrialoil and gas flow in the Mesozoic strata drilling WKB Basin.The WKB Basin is Mesozoic oil and gas reservoir, the reservoir experienced longtectonic action, so has many and miscellaneous pore structure type. It not only is theporosity and permeability ability is poor, but has an inclination angle, belonging to themiddle pore, fine throat of low permeability reservoir, therefore conventional Darcy’s lawis not applicable.To develop well a low permeability oil field, one should correctly understand thereservoir characteristics and seepage law, calculate the deep flow mechanics correctly, anddetermine the reasonable development program.With the development of the modern oil industry, the development of low permeability oilfield becomes more importance for the people. The low permeabilityreservoir has following apparent characteristics as compared with the middle and highpermeability reservoir: the fluid flow does not follow Darcy’s law, there is a pressuregradient flow, and the influence of gravity cannot be ignored.In this paper, for the low permeability reservoir of Mesozoic WKB Basin, throughpractical laboratory research sample, its microscopic pore structure characteristics of thereservoir are shown. On the basis of extensive research, low permeability reservoirsimulation method is studied, taking into account the pressure gradient and the influenceof gravity on the WKB Basin. The main contents and results obtained are as follows:1. Research on microscopic pore structure characteristics of Mesozoic WKB lowpermeability reservoir by applying pressure mercuryPore structure and physical properties has important theoretical and practicalsignificance in the oil and gas field development and practice. Capillary pressure dataanalysis is the most direct and effective way to evaluate reservoir pore structure. Mercurycurve in double logarithmic coordinate system is similar to hyperbolic. It is an importantmeans to study reservoir pore structure.In this paper, under the physical properties and mercury capillary pressure data oflater Cretaceous and earlier Jurassic reservoir of WKB Basin, I analysis and study of themicroscopic pore structure characteristics of the reservoir, and divide the reservoir, andprovide a reliable basis data for the further rational development of reservoir.2. Derivation and application of the formula to calculate relative permeabilitycurves considering starting pressure gradient and the gravitational influenceOil-water two-phase relative permeability curves can obviously response thetwo-phase flow characteristics. In theory, the main physical and chemical properties of thereservoir and fluid, such as permeability and pore structure, oil viscosity and oil flow ratio,and surface wettability and oil boundary layer thickness, can be reflected in relativepermeability curves. The characteristics relative permeability curves also reflect the waterflooding characteristics and effects of the different types of reservoir.Mine field relative permeability is generally obtained by indoor floodingexperimentally. In indoor relative permeability measurements, according to the theoretical basis for the experimental design, the measuring methods can be divided into two types,i.e., a "steady state methods" and "non-steady state method".Currently widely used JBN method only consider the impact of starting pressuregradient, but do not consider the influence of gravity, so there are some limitations.In this paper, using the traditional calculation of relative permeability（JBN method）,I introduced calculation method of oil and water two-phase relative permeability withconsidering starting pressure gradient under the condition of tilt formation, prepared thecorresponding utility software, and applied to oil-water two-phase relative permeability ofWKB Basin Mesozoic low porosity and low permeability oil and gas reservoirs.3. Model establishment and numerical simulation of low porosity and lowpermeability oil-water two-phase flow considering starting pressure gradient and theinfluence of gravityBased on the low permeability reservoir oil-water two-phase non-linear flow modelwith considering starting pressure gradient and the influence of gravity, I established aone-dimensional oil-water two-phase non-linear flow mathematical model for lowpermeability reservoir, constructed the corresponding finite difference format and irregulargrid system, gave a one-dimensional two-phase low-permeability reservoirs nonlinearflow numerical model. In addition, according to the mathematical model, numerical model,I solved the equation using IMPES method and constructed a corresponding computerprogram.This program was applied to one-dimensional nonlinear low permeability reservoirwater two-phase flow simulation problems under the different boundary conditions. Ianalyzed the simulation results and compared it with the actual development of dynamicto verify the correctness of the model and calculation procedures. Studies have shown thatthe impact of strata slope to low permeability reservoir develop dynamic is more apparent.更多还原