摘要
塔南凹陷是塔木察格盆地油气勘探的重要凹陷，但一直以来缺乏对盆地热演化史和油气成藏期次的系统研究。为此，采用多种方法对塔南凹陷近百个地层测温数据和330个有机质镜质体反射率数据进行统计分析，认为塔南凹陷地层温度随着深度的增加呈线性增加，为典型的传导型地温场特征；早白垩世各组地层沉积时期地温梯度为4．48℃／hm一5．37℃／hm，均大于现今地温梯度；早白垩世至今，塔南凹陷地温场处在一个降温的过程。同时开展单井热演化史和生排烃史模拟，认为塔南凹陷地层热演化程度定型于伊敏组末期；塔南凹陷主力烃源岩在早白垩世末伊敏组时期开始排烃，但该时期排烃量很小，晚白垩世青元岗组时期（95～70Ma）开始大量排烃，约占烃源岩总排烃量的85％。结合构造、沉积演化分析，厘定晚白垩世青元岗组为油气排出烃源岩运移至圈闭聚集成藏的关键时期，是塔南凹陷主要油气成藏期次。
South Tumtsag Sag is a very important sag for oil ＆ gas exploration in Tumtsag Basin. For quite a long time, the systematc researches on the geothermal evolution history and stage-time of petroleum reservoir formation have not been engaged. Therefore many methods are adopted to statistically analyze almost hundred of tested geo- thermal data and 330 Ro data of the organic matters. The studies show that the geothems rise linearly with the in- crease of the depth--the typical characteristics of transmitting-type geothermal field; the geothermal gradients in each sedimentary formation of Early Cretaceous system ranged from 4.48 ~C/hm to 5.37 ~C/hm, which are greater than the present. From Early Cretaceous period to now, the field in South Tumtsag Sag has experienced the process of temperature reduction. At the meantime, the stimulations of the histories of the individual wellg geothermal evo- lution and hydrocarbon generation ＆ expulsion are conducted. The achievements prove that the geothermal evolution degree was finished in the stage of Late Yimin Formation ; the primary petroleum source rock in South Tumtsag Sag began to expel hydrocarbon at the stage of Yimin Formation （ the end of Early Cretaceous period ） , but the amount was small ; while the large amount of hydrocarbon was expelled at the stage of Qingyuangang Formation （ 95-70 Ma, Late Cretaceous period） , which was almost 85% of total expelled hydrocarbon. Combined with the structures and sedimentation-evolution analyses, the latter is calculated and determined as the key reservoir-forming stage for the hydrocarbon expulsion-migration and being entrapped, which is the main petroleum reservoir-forming stage-time in South Tumtsag Sag.
出处
《大庆石油地质与开发》
CAS
CSCD
北大核心
2013年第1期59-64,共6页
Petroleum Geology & Oilfield Development in Daqing
基金
中同石油天然气集团公司重点项目（2008ZX05001-001）资助.
关键词
地温场
热演化史
生排烃史
成藏期次
塔南凹陷
塔木察格盆地
geothermal field
thermal evolution history
generated ＆ expelled hydrocarbon histories
reservoir- forming stage and times
South Tumtsag Sag
Tumtsag Basin
