地学前缘 ›› 2025, Vol. 32 ›› Issue (5): 12-27.DOI: 10.13745/j.esf.sf.2024.12.86

• 深部过程示踪 • 上一篇    下一篇

羌塘盆地构造——热演化史研究现状及进展

任战利1,2(), 杨鹏1,2, 祁凯1,2, 崔军平1,2, 于强3, 程鑫1,2, 黄雷1,2, 陈刚1,2, 姚举文1,2   

  1. 1.西北大学 地质学系 大陆动力学国家重点实验室, 陕西 西安 710069
    2.西安市多种能源资源勘探开发重点实验室, 陕西 西安 710069
    3.长安大学 地球科学与资源学院, 陕西 西安 710054
  • 收稿日期:2024-09-12 修回日期:2024-12-06 出版日期:2025-09-25 发布日期:2025-10-14
  • 作者简介:任战利(1961—),男,教授,博士生导师,矿产与普查勘探国家重点学科学术带头人,主要从事盆地构造-热演化史与油气成藏评价、地热资源评价与开发的教学科研工作。E-mail: renzhanl@nwu.edu.cn
  • 基金资助:
    国家自然科学基金专项项目“羌塘盆地构造-热体制与烃源岩热演化时空差异(42241204)”

Research status and progress of tectonic-thermal evolution history in Qiangtang Basin

REN Zhanli1,2(), YANG Peng1,2, QI Kai1,2, CUI Junping1,2, YU Qiang3, CHENG Xin1,2, HUANG Lei1,2, CHEN Gang1,2, YAO Juwen1,2   

  1. 1. State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi’an 710069, China
    2. Xi’an Key Laboratory of Multi-energy Exploration and Development, Xi’an 710069, China
    3. School of Earth Science and Resources, Chang’an University, Xi’an 710054, China
  • Received:2024-09-12 Revised:2024-12-06 Online:2025-09-25 Published:2025-10-14

摘要:

盆地热演化史对油气生成、成藏和赋存有重要控制作用,羌塘盆地作为我国大型中生代海相含油气盆地,其热体制和烃源岩热演化史时空差异的不明晰是制约油气勘探取得突破的关键科学问题。本文在对大量文献调研的基础上,结合自己的研究工作,综合分析了与羌塘盆地热演化史研究密切相关的现今地温场、盆地类型和抬升冷却过程、热成熟度和热演化过程、热演化史和生烃史4个方面的研究现状和进展。羌塘盆地“小块体-多阶段-强变形”的特殊构造特征,导致其原型盆地性质复杂化,并使得不同地区、不同构造单元在沉积-沉降变迁、构造变形、不整合面发育、岩浆活动、抬升冷却过程和期次等方面表现出显著差异性。这对盆地构造-热体制、烃源岩热演化史以及油气的生成、成藏、保存与破坏产生重要的影响。羌塘盆地后期构造运动和强烈的岩浆活动,对镜质体反射率等热演化指标有重要影响。根据构造和岩浆活动等的不同,将镜质体反射率与深度剖面划分为正常埋藏型、火成岩影响型和断裂影响型等。对盆地构造-热演化史恢复有重要影响的盆地类型、不同构造单元抬升冷却历史和差异性认识的不统一,制约了盆地动力学模型的建立和构造-热演化史恢复的深化。不同专家获得的热流值和地温梯度差异大,有中、高温型和低温型盆地的不同认识。烃源岩热演化程度的准确确定难度较大,根据已有分析结果,建立了羌塘盆地不同层位烃源岩反射率与热解峰温关系图版,该图版的建立对确定烃源岩成熟度具有重要作用。不同构造单元早白垩世以后改造强度差异大,抬升过程及剥蚀量的差异、埋藏史的差异和热演化史的不同,导致生成期次有一次、二次生烃期次的不同认识和具体时间的明显差异。羌塘盆地南部边缘白垩系与唢呐湖组、康托组之间存在热演化程度间断说明盆地南缘侏罗系烃源岩最大热演化程度是在唢呐湖组、康托组沉积之前达到的。因此,烃源岩热演化程度剖面显示羌塘盆地大部分地区烃源岩主生烃期在早白垩世和以前。针对盆地热演化史研究现状和进展,明确了热演化史研究存在的4个关键问题和进一步的攻关研究方向:(1)构造单元差异性沉降与隆升过程的恢复;(2)羌塘盆地现今地温场和关键时期盆地动力学模型建立;(3)多地质因素(差异性沉降-隆升、推覆构造、断裂活动和岩浆活动)对热演化程度的影响;(4)中生界不同构造单元烃源岩热演化史恢复和生烃史差异模式建立。羌塘盆地热演化史研究对探讨青藏高原盆地热动力学演化,建立复杂热演化史和生烃史的时空差异模式,以及在羌塘盆地油气综合评价和勘探工作中取得突破都具有重要意义。

关键词: 生烃史, 盆地热历史, 古地温, 裂变径迹, 镜质体反射率, 油气勘探, 羌塘盆地

Abstract:

The thermal history of the Qiangtang Basin plays an important role in controlling the generation, accumulation and occurrence of oil and gas. As a large Mesozoic Marine oil-bearing basin in China, the thermal regime and the spatial and temporal differences of the thermal evolution history of source rocks are the key scientific problems restricting the breakthrough of oil and gas. Based on a large number of literatures and my own research work, this paper comprehensively analyzes the current research status and progress in four aspects closely related to the study of the thermal evolution history of the Qiangtang Basin: current geothermal field, basin type and uplift and cooling process, thermal maturity and thermal evolution process, and thermal evolution history and hydrocarbon generation history. The special structural characteristics of “small block - multi-stage and strong deformation” in Qiangtang Basin complicate the properties of the prototype basin, and lead to the differences of sediment-subsidence changes, tectonic deformation, unconformity, magmatic activity, and uplift and cooling processes and periods in different regions and tectonic units. These differences relate closely to the characteristics of the tectonic thermal regime of the basin, the thermal evolution history of the source rock, and the generation, accumulation, preservation and destruction of oil and gas. The late tectonic movement and strong magmatic activity of Qiangtang Basin have important influence on thermal evolution indexes such as vitrinite reflectance. According to different structure and magmatic activity, vitrinite reflectance and depth profiles are divided into normal variation type, igneous rock influence type and fault influence type. The disunity of basin types, uplift and cooling history of different tectonic units and understanding of differences that have an important influence on the restoration of tectonic thermal evolution history restricts the establishment of basin dynamic models and the restoration of tectonic thermal evolution history. The heat flow value and geothermal gradient obtained by different experts differ greatly, and there are different understandings of middle, high temperature and low temperature basins. It is difficult to accurately determine the thermal evolution degree of source rocks. According to the existing analysis results, the relationship between reflectance and pyrolysis peak temperature of source rocks in different strata of Qiangtang Basin has been established, and the establishment of the chart has an important role in determining the maturity of source rocks. After the Early Cretaceous, the transformation intensity of different tectonic units varied greatly, and the differences in uplift process, denudation amount, burial history and thermal evolution history led to the obvious differences in the understanding of the first and second hydrocarbon generation stages and the specific time. The discontinuity of thermal evolution between the Cretaceous and Suonahu and Kangtuo formations in the southern margin of the Qiangtang Basin indicates that the maximum thermal evolution of the Jurassic source rocks in the southern margin of the basin was reached before the deposition of Suonahu and Kangtuo formations. Therefore, the thermal evolution profile of source rocks shows that the main hydrocarbon generation period of source rocks in most areas of Qiangtang Basin is in the Early Cretaceous and before. According to the current situation and progress of the research on the thermal evolution history of the basin, four key problems and further research directions in the study of thermal evolution history were identified: (1) Recovery of differential settlement and uplift process of tectonic units; (2)Establishment of current geothermal field and basin dynamics model in critical period of Qiangtang Basin; (3) The influence of multiple geological factors (differential sediment-uplift, nappe structure, faulting activity, magmatic activity) on the thermal evolution process; (4)Restoration of thermal evolution history and establishment of differential model of hydrocarbon generation history of source rocks of different tectonic units in Mesozoic. The study of the thermal evolution history of the Qiangtang Basin is of great significance to explore the thermal dynamic evolution of the Qinghai-Tibet Plateau basin, establish the spatio-temporal difference model of complex thermal evolution history and hydrocarbon generation history, and make breakthroughs in comprehensive oil and gas evaluation and exploration in the Qiangtang Basin.

Key words: hydrocarbon generation history, basin thermal history, ancient earth temperature, fission track, vitrinite reflectance, oil and gas exploration, Qiangtang Basin

中图分类号: