塔里木盆地顺北地区东西部海相油气成藏差异  

Differences in marine hydrocarbon accumulation between the eastern and western parts of Shunbei area, Tarim Basin

作　　者：漆立新[1] 丁勇[1] QI Lixin;DING Yong(Northwest Oilfield Company,SINOPEC,Urumqi,Xinjiang 830011,China)

机构地区：[1]中国石化西北油田分公司,乌鲁木齐830011

出　　处：《石油实验地质》2023年第1期20-28,共9页Petroleum Geology & Experiment

基　　金：中国石化科技部项目“满加尔坳陷及周缘下古生界油气成藏条件与选区评价”(P20063-1)资助。

摘　　要：塔里木盆地顺北地区东西部海相油气成藏差异明显,自东向西油气主要表现为由富到贫,勘探风险明显加大。通过对满加尔坳陷西缘的顺北东部和阿瓦提坳陷东缘的顺北西部油气成藏的分析,对比海相油气成藏条件的差异性,明确二者成藏差异的原因。以顺北1、4、8号断裂带东北段为代表的顺北东部近年来不断获得高产,油气多期成藏,油气富集特征明显;但阿瓦提坳陷东缘的顺北西部钻探结果不理想,表现为以早期成藏为主,且油气成藏规模不大。顺北东西部存在烃源层分布条件、生烃演化史、烃源资源规模、成藏期及成藏模式等差异,主要表现为东部多源多期成藏和西部单源单期成藏。顺北东部紧邻满加尔生烃坳陷区,长期处于四源供烃条件,属于多源多期成藏;而顺北西部要么是本地的寒武系玉尔吐斯组烃源岩早期成藏,要么是阿瓦提坳陷奥陶系烃源岩晚期成藏,属于单源单期成藏。阿瓦提东缘英买力油田及近年来英西1井奥陶系的突破表明,阿瓦提海相油气以海西晚期成藏为主,喜马拉雅期成藏为辅。阿瓦提坳陷周缘烃源岩发育相对较差,海相油气藏分布局限,油气资源规模也有限。From the eastern to the western part of Shunbei area in the Tarim Basin, the accumulations of marine oil and gas obviously decrease with the exploration risks significantly increasing. To find out the reason for the differences, the oil and gas accumulations in the eastern Shunbei area on the western margin of Manjiaer Depression and the western Shunbei area on the eastern margin of Awati Depression were analyzed, and the differences of accumulation conditions were discussed. In recent years, the eastern part of Shunbei oil and gas field, which is represented by the northeastern section of Shunbei No.1, 4 and 8 belts, has continuously achieved high yield with multiple stages of oil and gas accumulations and obvious oil and gas enrichment characteristics. While in the western part of Shunbei area, only early-stage accumulations with small scale were discovered. There are differences in the distribution conditions of source beds, hydrocarbon generation evolution history, source resource scale, reservoir-forming period and reservoir-forming mode between the eastern and western parts of Shunbei area, which leads to multi-source and multi-stage accumulation in the east and single-source and single-stage accumulation in the west. Adjacent to the Manjiaer hydrocarbon-generating depression, the eastern part of Shunbei area has favorable accumulation conditions such as pathways for vertical migration, targets for hydrocarbon migration of various sources, qualified cap rocks and lateral sealing, and multiple stages of hydrocarbon generation with strong intensity, resulting in multi-source and multi-stage accumulation. While in the western part of Shunbei area, there is single-source and single-stage accumulation sourced from either local Cambrian Yurtus Formation or Ordovician in the Awati Depression. Breakthroughs in Ordovician in the Yingmaili Oilfield on the eastern margin of Awati Depression and well Yingxi 1 in recent years indicate that the accumulation of marine oil and gas mainly took place in the late Hercynian pe

关 键 词：成藏期 成藏模式 烃源岩 寒武系 奥陶系 顺北地区 塔里木盆地 

分 类 号：TE122.3[石油与天然气工程—油气勘探]