滇黔北坳陷寒武系筇竹寺组岩相古地理特征与优质页岩展布  

Lithofacies Paleogeography and Distribution of High-quality Shale of the Cambrian Qiongzhusi Formation in the Dianqianbei Depression

作　　者：罗锦宇 祝海华[1,2] 梁兴 张介辉 张廷山[1,2] 闵华军 张喜 邹辰[3] 李军君 LUO JinYu;ZHU HaiHua;LIANG Xing;ZHANG JieHui;ZHANG TingShan;MIN HuaJun;ZHANG Xi;ZOU Chen;LI JunJun(School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;Sichuan Natural Gas Geology Key Laboratory,Southwest Petroleum University,Chengdu 610500,China;PetroChina Zhejiang Oilfield Company,Hangzhou 310023,China;School of Urban and Rural Planning and Construction,Mianyang Normal University,Mianyang,Sichuan 621000,China)

机构地区：[1]西南石油大学地球科学与技术学院,成都610500 [2]西南石油大学天然气地质四川省重点实验室,成都610500 [3]中国石油浙江油田公司,杭州310023 [4]绵阳师范学院城乡建设与规划学院,四川绵阳621000

出　　处：《沉积学报》2023年第4期1257-1270,共14页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(41772150);国家科技重大专项(2017ZX05063002009)。

摘　　要：滇黔北地区筇竹寺组早期沉积的黑色页岩是重要的烃源岩层。为明确其岩相古地理演化特征,揭示优质页岩展布规律,通过区域地质调查、野外露头、岩心、薄片、扫描电镜及钻井资料的综合研究,对滇黔北坳陷筇竹寺组上、下段的岩相古地理演化特征进行了恢复。筇竹寺组总体表现为西部薄,拉张槽内及东部厚的特点,同一沉积期内岩石类型也具有区域性差异,下段沉积期内西部地区以砂岩为主,中部与东部地区以泥页岩为主。主要沉积相类型为浅海陆棚相,上、下段水体深度不同,具有不同的沉积相特征,可细分为6种微相。下段地层由西至东依次主要发育浅水砂质陆棚微相、深水泥质陆棚微相。上段地层由西向东依次主要发育浅水砂质陆棚微相、浅水泥质陆棚微相以及浅水砂泥质陆棚微相。筇竹寺组优质烃源岩为黑色页岩及炭质页岩,总有机碳(TOC)含量普遍高于2%,泥质深水陆棚亚相是优质页岩发育的最有利的相带。纵向上,优质页岩主要发育在筇竹寺组下段底部;平面上,优质页岩主要沿研究区中部受拉张槽控制的CL1井、B1井、Z101井、镇雄JZ1井以及FS1井一带及东部地貌低且水体深度较深的金沙—遵义地区展布,是有利的优质页岩勘探区域。The black shale deposited during the early Qiongzhusi Formation in the Dianqianbei Depression is an important hydrocarbon source rock.The evolution of the lithofacies paleogeography in the upper and lower members of the Qiongzhusi Formation was restored in a thorough study of the regional geology,field outcrops,cores,thin sections,scanning electron microscopy and drilling data.The strata are thin in the west,and thicker in the tension trough and in the east.The rock types deposited during the same sedimentary periods also display regional differences.In the lower sedimentary period,the western region consists mainly of sandstone,whereas the central and eastern regions consist mainly of shale,with shallow sea-shelf facies as the main facies type.The upper and lower sections indicate varying water depths and sedimentary facies comprising six microfacies.From west to east,the lowest stratum consists mainly of shallow-water sandy shelf microfacies and deep-water argillaceous shelf microfacies,and the upper stratum mainly comprises shallow-water sandy shelf microfacies,shallow-water argillaceous shelf microfacies and shallow-water sandy argillaceous shelf microfacies.The high-quality source rocks of the Qiongzhusi Formation are black shale and carbonaceous shale,with TOC(Total of Organic)content generally above 2%.The argillaceous deepwater shelf subfacies is the most favorable for the development of high-quality shale.Vertically,the high-quality shale mainly occurs at the base of the lowest section of the Qiongzhusi Formation.In plane,it is mainly found in the section along wells CL1,B1,Z101,JZ1 and FS1,controlled by the tension trough in the middle of the study area.In the east,the low-landform and deep-water deposition Jinsha-Zunyi area favors exploration for high-quality shale.

关 键 词：岩相古地理 滇黔北坳陷 筇竹寺组 优质页岩 

分 类 号：P618.13[天文地球—矿床学]