塔里木盆地塔北地区三叠系烃源岩特征及展布  

Characteristics and distribution of Triassic source rocks in Tabei area,Tarim Basin

作　　者：丁勇 林静文 潘泉涌 Ding Yong;Lin Jingwen;Pan Quanyong(Exploration and Development Research Institute,Northwest Oilfield Branch Corporation,SINOPEC,Ürümqi 830011)

机构地区：[1]中国石油化工股份有限公司西北油田分公司勘探开发研究院,乌鲁木齐830011

出　　处：《地质科学》2024年第5期1198-1211,共14页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中石化科技部项目“满加尔坳陷及周缘油气成藏主控因素与选区评价”(编号:P23186)资助。

摘　　要：烃源岩是控制常规和非常规油气藏形成与分布的关键性因素之一。本研究通过系统测试塔里木盆地塔北地区三叠系泥岩的有机质丰度、类型及成熟度,分析了其烃源岩的空间展布特征,进而开展了有效烃源岩区预测。研究表明,三叠系泥岩TOC含量分布在0.75%~4%区间,有机碳丰度整体中等偏好,有机质类型以Ⅲ型干酪根为主,Ro分布在0.5%~0.9%,成熟度处于生油窗早-中期,生烃潜力整体偏低。哈拉哈塘组T_(3)h^(2)段泥岩有机碳含量及生烃潜力整体高于阿克库勒组T_(2)a^(2)段和T_(2)a^(4)段及柯吐尔组(T_(1)k)泥岩。由北向南方向,T_(2)a^(4)段、T_(2)a^(2)段及T_(1)k层段泥岩有效厚度均具有增厚趋势,T_(3)h^(2)段泥岩有效厚度则逐渐增加,且有机碳丰度由中等水平变好。由西向东方向,T_(1)k层段泥岩厚度整体变化不大,而T_(2)a^(2)段、T_(2)a^(4)段及T_(3)h^(2)段厚度均逐渐增加,且有机碳水平均较高。烃源岩的平面分布特征受沉积相控制,从T_(1)k层位到T_(2)a^(4)段及T_(3)h^(2)段泥岩,有效烃源岩区持续向北迁移。研究揭示了塔北地区三叠系烃源岩展布的控制机理,可为该区下一步常规和非常规油气勘探部署提供借鉴。By systematically measuring organic matter(OM)abundance,type and thermal maturity of the Triassic mudstones in the Tabei area of the Tarim Basin,this study analyzed the source rock spatial distribution and predicted the effective source rock region.Results show that the TOC content of the Triassic mudstone ranges from 0.75%to 4%,indicating a moderate to good level of OM abundance.The OM type is dominated by typeⅢkerogen,and the Ro value is in a range of 0.5%~0.9%,suggesting early to middle oil-generation window and a low hydrocarbon generation potential.The OM adundace and hydrocarbon generation potential of the T_(3)h^(2) mudstone in the Halahatang Formation are higher than the T_(2)a^(2) and T_(2)a^(4) members in the Akkule Formation and the T_(1)k mudstone in the Ketur Formation.From north to south,the effective mudstone thickness of the T_(2)a^(4),T_(2)a^(2) and T_(1)k intervals show an increasing trend,while the T_(3)h^(2) mudstone shows a reverse trend and its OM level is changed from moderate to good.From west to east,the T_(1)k mudstone thickness remains stable,while the thickness of the T_(2)a^(4),T_(2)a^(2) and T_(3)h^(2) members gradually increases and the OM level is relatively higher.The effective source rock region continues to migrate northward from the layer of T_(1)k to T_(2)a^(4) and T_(3)h^(2) members which is controlled by the sedimentary facies.

关 键 词：塔北地区 三叠系烃源岩 有机质丰度 有机质类型 成熟度 

分 类 号：TE122[石油与天然气工程—油气勘探]