准噶尔盆地乌尔禾—风南地区百口泉组储层有利成岩相

Favorable diagenetic facies of Baikouquan formation in Wuerhe-Fengnan area,Junggar basin

为明确准噶尔盆地乌尔禾—风南地区百口泉组成岩作用及成岩相,根据岩心分析化验数据,确定百口泉组储层物性特征;根据岩石薄片和扫描电镜观察结果,确定百口泉组成岩作用类型及强度;根据X线衍射结果,确定黏土矿物组分及体积分数;根据岩心薄片及其测井曲线特征,采用"物性加主控因素"分类方法,划分成岩相类型并建立各成岩相测井响应特征,确定成岩相分布规律,预测有利成岩相分布区。结果表明:百口泉组储层主要经历压实作用,碳酸盐、黏土矿物、黄铁矿、硅质胶结作用,以及长石、石英溶蚀作用。储层可划分为5种成岩相类型,即特低孔渗杂基充填相、中孔渗弱压实强溶蚀相、低孔渗强压实强溶蚀相、特低孔渗方解石胶结相和特低孔渗强压实相,其中中孔渗弱压实强溶蚀相和低孔渗强压实强溶蚀相为有利成岩相。中孔渗弱压实强溶蚀相主要分布于乌009—风4井区,低孔渗强压实强溶蚀相主要分布于乌2—风南7—夏75井区。该分析结果可为研究区优质储层预测提供地质依据。

In order to clarify the diagenesis and diagenetic facies of the Baikouquan formation in WuerheFengnan area,Junngar basin,China.The physical properties of the Baikouquan reservoir were determined by the core analysis and laboratory data.Thin section observation and scanning electronic microscopy were used to determine diagenetic types and their strength.X-ray diffraction was conducted to determine the composition of clay minerals and their content.According to a large number of thin sections and their corresponding logging curves,the types of diagenetic facies were divided and the response characteristics of each diagenetic logging were established to determine the distribution characteristics of diagenetic facies and to predict distribution area of favorable diagenetic facies based on the classification method of ＂physical properties and controlling factors＂.The results demonstrate that the reservoir mainly experienced compaction,cementation of carbonate,argillaceous,siliceous and pyrite,and dissolution of feldspar and quartz.The reservoir could be divided into 5 diagenetic facies：Ultra-low porosity and permeability matrix-filling facies,medium porosity and permeability weak compaction-strong dissolution facies,low porosity and permeability strong compaction-strong dissolution facies,ultra-low porosity and permeability calcite cementation facies,ultra-low porosity and permeability strong compaction facies.The favorable diagenetic facies were medium porosity and permeability weak compaction-strong dissolution facies and low porosity and permeability strong compaction-strong dissolution facies.Medi-um porosity and permeability weak compaction-strong dissolution facies was mainly distributed in the Wu009-Feng4 well blocks.Low porosity and permeability strong compaction-strong dissolution facies was mainly distributed in the Wu2-Fengnan7-Xia75 well blocks.The analysis of diagenetic facies can provide geological basis for high quality reservoir prediction.