Research On Characteristics Of The Yanchang Formation Reservoir Petrology In Xunyi Exploration Area Of Ordos Basin

Aimed at no comprehensive study of the characteristics of the Yanchang formation reservoir petrology in Xunyi exploration area, based on collation and analysis of previous data and the author’s mastered material, this paper expects to conduct a comprehensive analysis of the Yanchang formation petrological characteristics in Xunyi exploration area, and eventually can provide a reference value in predicting the distribution of high quality reservoirs in Xunyi exploration area.Description and sampling of outcrop and drilling core, indoors on the collected rock samples making rock slice and identification, casting rock slice, for production and thin sheet, mercury injection analysis, SEM, cathodoluminescence and five sensitivity analysis. It is known that the main rock type is feldspathic lithic sandstone, lithic feldspathic sandstone, litharenite and arkose; skeleton particles include quartz, feldspar and lithic, interstitial materials is mainly composed of terrigenous matrix and authigenic cements; rock granularity is mainly in the range of fine sand, probability curve type of granularity is mainly two-stage and three-stage; the rock is moderate- better sorting, mainly subangular, mainly porous cementation, line contact, point contact, floating three kinds contactless manner, compositional maturity and textural maturity is low. Reservoir space include pores, cracks and mixed pores, pore throat is mainly fine pore- micro throat type; five sensitivity is low. Sedimentary environment and sedimentary facies, diagenesis and tectonism are the main factors to influence reservoir properties. Diagenetic stage is late diagenetic stage A Better reservoir properties position generally located in parts of the river.The following conclusions: Xunyi exploration area is located in the transition zone of tectonic units, coupled by the strong influence of the late tectonic movement, in making high-quality reservoir prediction we should not only consider traditional controlling factors of internal basin, but also consider anticline formed by tectonic movement and the function of crack.