The Research Of Pore Structure Of Sandstone Reservoirs Of Sanjianfang Oil Layer In Qiulin Oilfield

This article on the Sanjianfang Oil layer in Qiulin Oilfield low-permeability oil reservoir facies in distribution, diagenesis, reservoir rock characteristics and other geological features were analyzed, focused on the reservoir of micro-pore structure and a systematic study of factors. Through thin sections, scanning electron microscopy, high-pressure mercury technology and rock and mineral analysis methods and techniques, on the Qiulin Oilfield oil reservoir Formation in the Sanjianfang Oil layer studied, analyzed, discussed the study area porous sandstone reservoir types, pore structure and pore throat ratio, microscopic characteristics of the reservoir, and the sedimentation, diagenesis and petrology characteristics of the micro pore structure, the conclusions run as follows:Study area, the top oil reservoir of Sanjianfang oil reservoir is braided delta front sedimentary facies, the lower oil reservoir is alluvial fan delta front, and further divided into there are four microfacies:underwater distributary channel and mouth bar, distributary Sand Bay and the front sheet. Sandstone reservoirs are mainly feldspathic lithic sandstone, light gray color, gray and light gray with green; it witnesses low compositional maturity and texture maturity, detrital components in the average content of 27.9% quartz, feldspar content of 19.2% on average, the average content of 52.9% cuttings. Rock debris complex components, mainly igneous rock (39.7%), metamorphic rocks (11.7%), in addition to trace siltstone and mudstone has almost no sedimentary rock debris. Diagenesis of the main types of experience: compaction, cementation, replacement and dissolution. Diagenetic stage under the division of its standard, can be divided into the diagenetic A period.The types of sandstone pore of the Sanjianfang Oil layer in Qiulin Oilfield are mainly intergranular pores, holes and debris dissolution of feldspar dissolved pore, followed by micro-cracks, fewer intergranular pores and pore complex-based solvent. According to cast thin section and scanning electron microscopy analysis of the main types come to the reservoir throat dotted throat, sheets or bent sheet mainly throat, in the locally developed necking throat, tube-shaped throat; generally poor connectivity. Comprehensive analysis, the impact of the reservoir parameters (especially infiltration rate) and pore characteristics of the main parameters:skewness, median radius, the value of pressure, withdrawal of mercury saturation. Pore structure of the final classification based on the principle of the Sanjianfang Oil layer in Qiulin Oilfield pore structure classified as gradeâ…¡. Comprehensive analysis on the Sanjianfang Oil layer in Qiulin Oilfield Formation in reservoir rock pore structure can be concluded that the main factors:compositional maturity,texture maturity, sedimentary structure and sedimentary facies distribution patterns determine the distribution of pore structure development of the situation; diagenesis in the study area a variety of sandstone reservoirs influence the pore structure of different. Compaction, cementation to the heterogeneity of the reservoir to enhance the micro, Complex pore structure, and dissolution so that the roundabout was reduced throat, to improve the pore structure; interstitial material while the composition and content of pore type, size, number, proportion of the pore and the contact between particles, etc. these factors are all micro-pore structure of reservoir rocks have an impact.