鄂尔多斯盆地东部上古生界盖层封闭性能评价  

Sealing capability evaluation of the Upper Paleozoic cap rock in the eastern Ordos Basin

作　　者：马东烨 陈宇航 王应斌[6] 郭明强 屈乐 赵靖舟[1,4] 吴和源 MA Dongye;CHEN Yuhang;WANG Yingbin;GUO Mingqiang;QU Le;ZHAO Jingzhou;WU Heyuan(School of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an 710065,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an Shiyou University,Xi’an 710065,China;Xi'an Key Laboratory of Tight Oil(Shale Oil)Development(Xi'an Shiyou University),Xi'an 710065,China;Unconventional Oil&Gas Branch,CNOOC Co.,Ltd.,Beijing 100016,China)

机构地区：[1]西安石油大学地球科学与工程学院,陕西西安710065 [2]油气资源与探测国家重点实验室,中国石油大学(北京),北京102249 [3]中国科学院海洋地质与环境重点实验室,山东青岛266071 [4]陕西省油气成藏地质学重点实验室,陕西西安710065 [5]西安市致密油(页岩油)开发重点实验室(西安石油大学),陕西西安710065 [6]中海石油(中国)有限公司非常规油气分公司,北京100016

出　　处：《天然气地球科学》2021年第11期1673-1684,共12页Natural Gas Geoscience

基　　金：国家自然科学基金(编号:41802128);中国石油大学(北京)油气资源与探测国家重点实验室开放课题基金(编号:PRP/open-2106);中国科学院海洋地质与环境重点实验室开放基金(编号:MGE2020KG10);西安石油大学2018年校级青年科研团队项目“碎屑岩沉积学与储层评价”(编号:2019QNKYCXTD05)联合资助。

摘　　要：鄂尔多斯盆地东部上古生界油气资源丰富,勘探开发潜力大。近年来,随着对该地区成藏条件研究的不断深入,人们逐渐认识到盖层的有效性对天然气成藏具有关键作用。基于实测泥岩突破压力数据,结合测井、岩心资料,建立了鄂尔多斯盆地东部上古生界盖层突破压力测井计算模型,研究了盖层的空间展布和突破压力分布,揭示了盖层封闭性的控制因素,并结合生产数据对盖层封闭性进行了综合评价。结果显示:鄂尔多斯盆地东部上古生界主要发育3套泥岩盖层:石千峰组、上石盒子组和山西组。石千峰组盖层厚度最大,分布连续,且成岩阶段处于中成岩A期,泥岩塑性高,韧性好,突破压力较高,封闭性能较好,为全区的区域盖层。上石盒子组盖层相对较厚,成岩阶段介于中成岩A期到中成岩B期,但泥质粉砂岩和细砂岩与泥岩频繁互层,泥岩非均一性强,突破压力最低,盖层封闭性最差。山西组泥岩盖层厚度最薄,分布局限。但埋深最大,成岩阶段已经进入中成岩B期,泥岩塑性增强,突破压力最高,封盖能力最好,为下伏本溪组-山西组气藏的直接盖层。The Upper Paleozoic in the eastern Ordos Basin are rich in oil and gas resources, showing great potential. In recent years, the effectiveness of cap plays a key role in gas accumulation with the deepening research in this area. Based on logging, core data, a logging model for the breakout pressure of the Upper Paleozoic cap rock in the eastern Ordos Basin was built. By applying this model, the spatial distribution and breakthrough pressure distribution of the Upper Paleozoic cap in the eastern Ordos Basin were studied, which reveals the controlling factors of cap rock sealing ability. By integrating production data, the comprehensive evaluation of rock sealing ability was discussed. The results show that there are three sets of mudstone caps in the Upper Paleozoic in the eastern Ordos Basin: The Shiqianfeng Formation, the Shangshihezi Formation and the Shanxi Formation.The cap in Shiqianfeng Formation is the thickest with wide distribution, and is in the middle diagenetic A stage.The mudstone has high plasticity and good toughness, showing the relatively high breakthrough pressure and good sealing performance, which is regional cap. The Shangshihezi Formation cap is between the middle diagenetic A stage and B stage. However, the pure mudstone is relatively thin due to the frequent interbedded of argillaceous siltstone and fine sandstone. Therefore the breakthrough pressure is the lowest, leading to the worst seal ability. The cap at the top of the Shanxi Formation is the thinnest, however, it is in the middle diagenetic B Stage due to the deepest burial depth, and the mudstone plasticity is enhanced, therefore the breakthrough pressure is the highest and the capping ability is the best.

关 键 词：鄂尔多斯盆地东部 盖层封闭性 突破压力 成岩作用 

分 类 号：TE122.1[石油与天然气工程—油气勘探]