鄂尔多斯盆地神木地区上古生界盖层物性封闭能力与石千峰组有利区域预测

对鄂尔多斯盆地神木地区上古生界泥质岩排替压力、孔隙度、渗透率、比表面积、扩散系数等物性封闭参数综合研究表明:物性封闭能力是影响天然气向上扩散运移的关键因素,通过各项参数具体分析并结合成岩作用等因素,建立了该区泥质岩物性封闭能力评价标准,纵向上评价结果为下石盒子组盒8、盒7及上石盒子组盒4、盒1四个层位的物性封闭能力相对较强,并选取具有代表意义的排替压力参数平面成图,结合其他地质条件,预测出对石千峰组成藏有利的三类区域,一类有利区分布在榆林以东地区,二类有利区分布在横山以南地区,三类有利区分布在神木以北地区。

Evaluation on Sealing Ability of Upper Paleozoic Caprocks Physical Property and Favorable Targets prediction of Shiqianfeng Formation in Shenmu Region, Ordos Basin

Based on the study of physical property sealing parameters such as displacement pressure, porosity, permeability,surface ratio, diffusion coefficient, etc.of Upper Paleozoic mudstones in Shenmu region, Ordos Basin, it can be concluded that physical propertysealing ability is a key parameter that affects the upward diffusion and migration of natural gas. On the basis of the analysis on thesephysical property sealing parameters and diagenesis, etc., evaluation criterion is established for the physical property sealing ability ofmudstones in this region.The plane evaluation shows the physical property sealing ability of He-8, He-7 layers in upper Shihezi Formation,and He-4, He-1 layers in lower Shihezi Formation are relatively strong, and the map is formed by choosing the representative displacementpressure parameter. In addition, combining the other factors, three type areas are predicted to be favorable for the reservoir-forming ofShiqianfeng Formation. Type I distributes at the east of Yulin area, while type II and type III distribute at the south of Hengshan Countyand at the north of Shenmu County respectively.