基于数值模拟的裂缝型储层岩石导电效率响应规律研究

Research on the Response Law of Conductivity Efficiency of Fractured Reservoir Rock Based on Numerical Simulation

裂缝型储层是非常规储层中重要的储层类型,目前在油气勘探的评价中起到重要作用。由于其储集空间多样、非均质性很强,不同类型储集空间物性具有明显差异,给测井识别和评价造成很大困难。本文利用数值模拟的方法来探究岩石导电效率对地层裂缝的响应规律,为裂缝型储层识别寻找新的方法。结合导电效率理论,利用数值模拟软件建立物理模型对不同裂缝宽度、裂缝倾角、孔洞大小、基岩孔隙度下的导电效率进行数值模拟计算及分析。研究表明:岩石导电效率随裂缝宽度、基岩孔隙度的增大而增大,随裂缝倾角、孔洞大小的增大而减小;且随着裂缝倾角的增大,裂缝的有效宽度逐渐减小,岩石导电效率随裂缝宽度的变化趋势越来越平缓;而随着孔洞大小的增大,裂缝整体更加不规则,岩石导电效率的变化趋势随裂缝宽度的增大越来越急剧。研究表明,岩石导电效率这一参数不同影响因素的响应明显。因此,对区分裂缝型储层的储集空间类型有重要的参考意义。

Fractured reservoirs are an important type of unconventional reservoirs, and currently play an important role in the evaluation of oil and gas exploration. Due to the variety of reservoir spaces and strong heterogeneity, the physical properties of different types of reservoir spaces are obviously different, which makes it very difficult for logging identification and evaluation. In this paper, the numerical simulation method is used to explore the response law of rock conductivity to formation fractures, and to find a new method for the identification of fractured reservoirs. Combined with the theory of electrical conductivity, numerical simulation software is used to establish a physical model to conduct numerical simulation calculations and analysis of electrical conductivity under different fracture widths, fracture inclination angles, pore sizes, and bedrock porosity. The research shows that the conductivity efficiency of rock increases with the increase of fracture width and bedrock porosity, and decreases with the increase of fracture inclination and pore size;and with the increase of fracture inclination, the effective width of fracture gradually decreases, the change trend of rock conductivity efficiency with fracture width becomes more and more gentle;with the increase of pore size, the cracks become more irregular overall, and the change trend of rock conductivity efficiency becomes more and more sharp with the increase of fracture width. The research shows that the rock conduction efficiency parameter responds obviously to different influencing factors. Therefore, it has important reference significance for distinguishing the storage space types of fractured reservoirs.