博格达地区中二叠统沉积环境与烃源岩特征

Sedimentary environment and the characteristics of hydrocarbon source rock of the Middle Permian in Bogda area

张奎华 宋明水 曹忠祥 王越 张关龙 薛雁1

中国石化胜利油田分公司勘探开发研究院，山东 东营 257015 中国石化胜利油田分公司，山东 东营 257000

Exploration and Development Research Institute, Shengli Oilfield Company, SINOPEC, Dongying 257015, China Shengli Oilfield Company, SINOPEC, Dongying 257000, China

博格达地区中二叠统芦草沟组与塔尔朗组广泛出露黑色页岩、油页岩，为该区重要的烃源岩层系。在对中二叠统典型剖面详细观察和精细测量的基础上，通过对泥页岩层系进行系统取样测试，分析了古沉积环境、总有机碳质量分数及生烃潜量等特征。结果表明：准噶尔盆地南缘芦草沟组三段黑色泥页岩多发育优质烃源岩，总有机碳质量分数平均为4.2%，Sr/Ba值（质量比）反映当时以咸水环境为主，间歇性出现半咸水环境，V/（V+Ni）值（质量比）反映当时为水体分层较强的极贫氧环境；吐哈盆地北缘塔尔朗组三段黑色泥页岩为好—优质烃源岩，总有机碳质量分数平均为2.5%，Sr/Ba值反映当时以半咸水—咸水环境为主，间歇性出现淡水环境，V/（V+Ni）值反映当时为水体分层较弱的贫氧环境。

Black shale and oil shale are widely exposed in the middle Permian Lucaogou Formation and Taerlang Formation in Bogda area, which are important hydrocarbon source strata in this area. On the basis of detailed observation and fine measurement of the typical section of the Middle Permian, the characteristics of the palaeo-depositional environment, total organic carbon content and hydrocarbon generation potential were analyzed by systematic sampling test of the mud shale series. The result shows that the black mud shale of the third member of Lucaogou Formation in the south margin of Junggar Basin is mostly high-quality source rock, with an average TOC content of 4.2%. The Sr/Ba value (mass radio) reflects that the environment was dominated by saltwater at that time, with intermittent occurrence of brackish water environment. The V/(V+Ni) value (mass radio) reflects the extremely poor oxygen environment with strong water stratification at that time. The black mud shale of the third member of the Taerlang Formation in the north margin of Tuha Basin is a good to high-quality source rock, with an average TOC content of 2.5%. The Sr/Ba value reflects that at that time the brackish water and salt water environment was dominant, and fresh water environment appeared intermittently. The V/(V+Ni) value reflects the poor oxygen environment with weak water stratification.

10.6056/dkyqt202101002