鄂尔多斯盆地东缘大宁—吉县地区山西组页岩岩相与沉积相特征

以鄂尔多斯盆地东缘大宁—吉县地区二叠系山西组为研究对象,综合应用岩心、薄片及测井资料,开展山32亚段岩相类型、岩相组合和沉积相研究,研究结果表明:山32亚段包括粉砂质泥岩/页岩相、纹层状层理含粉砂泥岩/页岩相、透镜状层理粉砂质泥岩/页岩相、钙质页岩相、煤层、碳质页岩相、黑色页岩相、波状层理泥质粉砂岩相、交错层理中—细砂...

Shale Lithofacies and Sedimentary Facies of the Permian Shanxi Formation,Daning-Jixian Area,Eastern Margin of Ordos Basin

A s ystematic study was conducted using cores， rock thin sections and drill logging data to identify lithofacies in the Daning-Jixian region of the Shanxi Formation and establish their association and sedimentary facies. Ten types of lithofacies were identified: massive silty mudstone or shale， silt-bearing mudstone or shale with small ripples， silty mudstone or shale with lenticular bedding， calcareous shale， coal， carbonaceous shale， black shale， muddy siltstone with wave bedding， middleto fine sandstone with tidal cross-bedding， and massive middle size sandstone. In additon， ten lithofacies were classified into four associations that reflect four depositional environments: tidal flat deposits （supratidal to intertidal zones）， lagoon deposits， tidal channel to tidal flat deposits and lagoon-tidal flat deposits. The study area lies within a marine-continental transitional facies sedimentary environment， the central part is a lagoon deposit， the southwestern and eastern parts comprise two barrier islands and a sand bar deposition area and barrier island， and in the north， a delta front transitioning to a tidal flat in the direction of the lake. The lithofacies association in the deep lagoon and tidal flat deposits（supra /intertidal zones） are favorable for the development of a high-TOC shale gas reservoir.