川中侏罗系大安寨段岩性测井识别标准及其应用

The Logging Identification Standard and Application of the Lithologic of Lower Jurassic Daanzhai in Central Sichuan Basin

川中侏罗系大安寨储层孔渗较差,属于典型的致密油,原油富集明显受岩性控制,识别不同岩性的空间展布成为制约工区下一步勘探的重要因素。以取芯资料为基础,分析不同测井曲线与取芯资料的对应关系,建立以自然伽马、声波时差、深浅双侧向为主的解释标准。介壳灰岩标准为GR<45 API,声波时差以低值为主,深浅双侧向以高值为主;泥页岩标准为GR>75API,声波时差相对较高,深浅双侧向低值;泥质介壳灰岩的标准为GR:45～75 API,声波时差相对较低,深浅双侧向相对高值。

The reservoir of the lower Jurassic Daanzhai in central Sichuan basin belongs to the typical dense oil whose permeability and porosity is very poor,the enrichment of crude oil is obvious controlled by lithology.How to effectively identify the spatial distribution of different lithology is the important factor to restrict the next step prospecting in the work area.Based on the core materials,it analyzes the relationship between logging curve and core materials,and establishes the lithologic identifying standard of Daanzhai based on the natural gamma ray,interval transit time and deep shallow laterolog as the main explanation curves.This new standard is defined as follows,GR 45API,sonic time curves with low value and deep shallow laterolog with high value is shell limestone.GR﹥75API,sonic time curves relatively high and deep shallow laterolog with low value is clay shale.GR： 45~75 API,sonic time curves relatively lower and deep shallow laterolog with high value is muddy shell limestone.