摘要
盐下层系内碳酸盐岩-蒸发岩体系是全球油气增储上产的重点领域,其源-储组合样式及分布规律成为制约油气勘探的关键。鄂尔多斯盆地奥陶系盐下碳酸盐岩-蒸发岩体系的烃源岩与储层发育分布规律研究表明:①多级次“隆-坳”格局控制了沉积底形差异,古气候的干湿变迁改变了古海洋环境条件,导致沉积分异,进而形成了不同的碳酸盐岩-蒸发岩沉积序列,发育不同的烃源岩和储层。②古隆起与次级隆起区主要发育干旱气候期的泥质白云岩烃源岩,古坳陷内发育湿润气候期的泥晶灰岩烃源岩。③同期古隆起与次级隆起带通常发育颗粒滩沉积,亦为底栖生物有利栖息区,是气候由湿润转向干旱过程中高盐度卤水渗透回流的优势区带,易发生白云石化作用,控制了晶粒白云岩、颗粒白云岩、微生物白云岩和斑状白云岩储层的分布。④构造与沉积分异作用控制了碳酸盐岩-蒸发岩体系烃源岩与储层的分布规律,中央古隆起及其周缘斜坡带与邻近古坳陷的乌审旗隆起及神木-米脂低隆发育有效源-储组合,是盐下层系油气勘探的有利地带。
The carbonate-evaporite system in the sub-salt sequence has been a key area for increasing oil and gas reserves and production.Its source rock-reservoir combination styles and distribution have become the key constraints on oil and gas exploration.Analyzing the development and distribution pattern of hydrocarbon source rock-reservoir in the sub-salt carbonate-evaporite system in the Ordos Basin,we explore the controlling factors.The results show that:the hierarchical“uplift-depression”structural pattern determines the sedimentary substrate variability,and the dry and wet paleoclimate changes alter the oceanic conditions,leading to sedimentary differentiation,which results in the formation of different carbonate-evaporite depositional sequences,and the development of various hydrocarbon source rocks and reservoirs.Paleo-uplifts and subordinate uplifts control the distribution of hydrocarbon source rocks for arid-climate argillaceous dolomites,and the paleo-depressions are favorable for the growth of hydrocarbon source rocks for wetclimate micrites;grainstone deposits are prone to developing in paleo-uplift and subordinate uplift zones,which are also a favourable habitat for benthic organisms.These zones are the dominant zones for the reflux of high-salinity brine in the process of the climate shifting from wet to arid,where the occurrence of dolomitization is widely seen,controlling the distribution of crystalline dolostone,grain dolostone,microbial dolostones and porphyritic dolostone reservoirs.Tectonic-sedimentary differentiation governs the distribution pattern of hydrocarbon source rocks and reservoirs in the carbonate-evaporite system.The slope zone around the Central paleo-uplift and the Wushenqi uplift and Shenmu-Mizhi low uplift zone adjacent to the paleo-depression have effective hydrocarbon source rock-reservoir combinations developed,favourable zones for oil and gas exploration in the sub-salt sequence.
作者
苏中堂
徐哲博
魏柳斌
师平平
张雷
任军峰
任静
吴浩文
朱梦涵
SU Zhongtang;XU Zhebo;WEI Liubin;SHI Pingping;ZHANG Lei;REN Junfeng;REN Jing;WU Haowen;ZHU Menghan(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu,Sichuan 610059;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu,Sichuan 610059;National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields,Xi’an,Shaanxi 710018;Research Institute of Exploration and Development,Changqing Oilfield Company,PetroChina,Xi’an,Shaanxi 710018)
出处
《石油与天然气地质》
北大核心
2026年第1期64-80,共17页
Oil & Gas Geology
基金
中国石油长庆油田创新联合体项目(2024D1JC06)
中国石油攻关性应用性科技专项(2023ZZ16YJ01)。
关键词
古气候
构造-沉积分异
碳酸盐岩-蒸发岩体系
白云岩
深层-超深层
马家沟组
奥陶系
鄂尔多斯盆地
paleoclimate
tectonic-sedimentary differentiation
carbonate-evaporite system
dolostone
deep to ultradeep reservoirs
Majiagou Formation
Ordovician
Ordos Basin
