随机建模技术在低渗透砂岩储层早期油藏描述中的应用——以鄂尔多斯盆地延长组陆相砂岩储层为例

Application of stochastic modeling to earlier oil reservoir description of low permeability sandstone reservoir——A case study of the continental sandstone reservoir in Yanchang Formation of Ordos Basin

鄂尔多斯盆地中部某地区延长组长6油层组属于典型的陆相成因低孔超低渗砂岩储层。开发早期,油藏描述阶段动静态的资料比较缺乏,要对油藏进行全面的研究和评价具有较大的难度。随机建模技术能够描述由于资料的缺乏引起的地质模型的不确定性。文章简要介绍了随机建模的基本原理,建立了鄂尔多斯盆地中部某地区延长组长6油层组的构造模型,用序贯指示模拟方法和序贯高斯模拟方法建立了目的层的沉积微相和物性参数的三维展布模型。生产实际表明,用随机建模方法建立的地质模型与实际生产动态符合率高,表明随机建模技术在我国陆相复杂储层早期油藏描述阶段有很大的适用性和实用性。

Chang 6 in Yangchang Formation in the middle part of Ordos Basin is a typical continental sandstone reservoir with low porosity and ultralow permeability. During the early stage of oil reservoir description, it is difficult to study and evaluate the oil reservoir thoroughly because of the absence of both the static and dynamic data. The technology of reservoir stochastic modeling is able to describe the indeterminacy of geological model caused by lack of information. It has briefly introduced basic principles of stochastic modeling, and established structural model of Chang 6 in Yanchang Formation in Ordos Basin as well as 3D spreading model of sedimentary micro facies in target layer with physical parameters by using the algorithms of SIS （Sequential Indicator Simulation） and SGS （Sequential Gaussian Simulation） separately in this paper. Practical operation has shown that the geological model by using stochastic modeling is very accordance with actual production, which indicates a great applicability and practicability of stochastic modeling used in oil reservoir description of early stage about continental complex reservoir in China.