姬塬地区长6储层成岩相特征及测井响应

Characteristics of Diagenetic Facies of Chang 6 Reservoir and Logging Response in Jiyuan Area

通过岩心观察并综合运用铸体薄片、扫描电镜、X射线衍射、物性以及压汞等基础测试资料,对姬塬地区长6致密砂岩储层的岩石学、孔隙结构等特征展开了研究,系统分析了不同类型成岩相及其微观孔喉特征。依据储层物性,结合主要的沉积特征、成岩矿物、填隙物及孔隙类型,研究区砂岩储层按照储集性能的好坏可划分为Ⅰ类(绿泥石膜胶结-残余粒间孔相)、Ⅱ类(长石溶蚀相)、Ⅲ类(高岭石胶结相)、Ⅳ类(碳酸盐胶结相)4种成岩相带,其中Ⅰ类、Ⅱ类储层物性较好,是研究区储层发育的有利成岩相带,Ⅲ类、Ⅳ类则为较差储集岩相带。选取了自然伽马、声波时差、电阻率等对成岩相响应较为敏感的测井曲线,利用岩心、薄片资料刻度测井曲线,研究各成岩相在自然伽马、声波时差等测井曲线上响应特征的差异性。通过对成岩相分布特征及其测井响应特征进行研究,可以合理评价低渗透砂岩储层并预测优质储层发育带,同时为后续的油气地质勘探提供可靠的理论基础。

Through core observation and comprehensive use of the casting thin slices,scanning electron microscopy,X-ray diffraction,physical property and mercury injection test data,this paper studies the lithology,physical property and pore structure characteristics of tight sandstone reservoir of Chang 6 in Jiyuan area and analyses systematically the different types of diagenetic facies and micro-pore throat characteristics of low permeability sandstone reservoirs.Based on reservoir physical properties,combined with major sedimentary characteristics,diagenetic minerals,interstitial and pore types,sandstone reservoir in the study area can be divided into ClassⅠ（chlorite cementation-membrane residual intergranular pore facies）,ClassⅡ（feldspar dissolution facies）,ClassⅢ（kaolinite cementation facies）and ClassⅣ（carbonate cementation facies）.Among them,ⅠandⅡ possess the reservoir physical properties favorable for the development of reservoir;andⅢandⅣare poor in reservoir rock facies.Different types of diagenetic facies on the natural gamma ray and acoustic time log response characteristics are summarized.The natural gamma ray,acoustic time difference and logging curves which are more sensitive to diagenetic facies as well as core data,and thin scale logging curves are employed to study the response characteristics difference of each type of diagenetic facies.The study of the distribution characteristics of diagenetic facies and logging response may enable a reasonable evaluation of low permeability sandstone reservoir and prediction of high quality reservoir development,and may provide reliable theoretical basis for subsequent geological exploration of oil and gas.