摘要
台北凹陷三工河组致密砂岩油气藏是吐哈盆地现实的油气接替领域,油气成藏过程一直未得到清晰的认识,制约着该领域的高效勘探。综合应用盆地模拟、构造演化史分析、流体包裹体测试等手段,对丘东洼陷三工河组致密砂岩油气藏烃源岩生排烃史、储层成岩演化史、区域构造演化史及油气充注史等关键成藏要素进行了模拟和分析,并对各成藏要素在地质历史中的匹配关系进行了系统研究。结果表明:烃源岩生排烃期、油气充注期、储层演化与构造背景的配置关系控制油气富集。丘东洼陷三工河组油气经历3期油气充注,第一期发生在早白垩世末期,在燕山Ⅱ幕的构造活动背景下,低熟原油在洼陷内低幅隆起和温吉桑构造高部位汇聚形成低熟油藏,由于该时期三工河组储层较为致密导致充注量有限;第二期充注为晚白垩世末,烃源岩处于成熟阶段并大量生油气,此时有机酸的形成改善了三工河组砂岩储层空间,有利于油气的充注,在温吉桑地区和丘东洼陷区低幅隆起部位(吉7H井附近)形成成熟油气藏;古近纪末期丘东洼陷下侏罗统烃源岩开始大量生气,此时储层已致密,洼陷区整体平缓且构造稳定,油气近源充注形成大规模致密凝析气藏(含油)并最终定型。研究证实丘东洼陷区三工河组具备大规模致密凝析气藏形成条件,是台北凹陷下侏罗统未来勘探的有利区域。
The tight sandstone reservoir of the Sangonghe Formation in Taibei Sag is an important succession field in Turpan-Hami Basin and the formation process has not been clearly understood,which restricts the effi⁃cient exploration in this field.Therefore,in this paper,basin simulation,structural evolution history analysis,fluid inclusion testing and other methods are comprehensively used to simulate and study the key reservoir form⁃ing factors of tight sandstone reservoirs in Sangonghe Formation of Qiudong sub-sag,including hydrocarbon generation and expulsion history of source rock,reservoir diagenetic evolution history,regional structural evolu⁃tion history,oil and gas charging history,and the matching relationship of these reservoir forming factors in geo⁃logical history is systematically studied.The results show that the hydrocarbon generation and expulsion period,hydrocarbon charging period,reservoir evolution and tectonic setting configuration control the enrichment of hy⁃drocarbon.The Sangonghe Formation experienced three stages of hydrocarbon charging in Qiudong sub-sag.The first stage occurred at the end of Early Cretaceous.Under the background of tectonic activity in the second stage of Yanshan Period,a limited amount of low-mature crude oil gathered in low-amplitude uplifts in depres⁃sion areas and higher positions of Wenjisang structure to form low-mature oil reservoirs,and the reservoir is rel⁃atively dense.The second stage occurred at the end of Late Cretaceous,a large amount of oil and gas were pro⁃duced by the mature source rocks while the expulsion of organic acids improved the sandstone reservoir space of Sangonghe Formation,which was conducive to the charging process of hydrocarbons and the mature oil and gas reservoirs were formed in the Wenjisang area and the low uplift area of Qiudong sub-sag(near Well J7H).At the end of Paleogene,the Lower Jurassic source rocks began to generate a lot of gas.At this time,the reservoir was tight,the depression area was flat with stable structures which create a suitable condition for hydrocarbon near-source charging to form a large-scale tight condensate gas reservoir(containing oil).It is proved that the Sangonghe Formation in Qiudong sub-sag favors the formation of large-scale tight condensate gas reservoirs,which is a promising area for future exploration of the Lower Jurassic in Taibei Sag.
作者
肖冬生
王柏然
姚宗森
李志远
贾雪丽
鲁宽
XIAO Dongsheng;WANG Boran;YAO Zongsen;LI Zhiyuan;JIA Xueli;LU Kuan(Exploration and Development Research Institute,PetroChina Tuha Oilfield Company,Hami 839009,China;School of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2024年第2期275-287,共13页
Natural Gas Geoscience
基金
中国石油天然气集团公司“十四五”重大专项课题“吐哈盆地深层/超深层致密砂岩气富集机理与关键评价技术研究”(编号:2022DJ2107)资助。
关键词
吐哈盆地
丘东洼陷
三工河组
致密油气藏
成藏过程
Turpan-Hami Basin
Qiudong sub-sag
Sangonghe Formation
Tight sandstone reservoirs
Hydrocarbon accumulation process
