The Early Cambrian Mianyang-Changning Intracratonic Sag and Its Control on Petroleum Accumulation in the Sichuan Basin, China
The Early Cambrian Mianyang-Changning Intracratonic Sag and Its Control on Petroleum Accumulation in the Sichuan Basin, China
复制标题
四川盆地早寒武世绵阳—长宁克拉通内凹陷及其对油气成藏的控制
DOI：
10.1155/2017/6740892
复制
发表时间：
2017-01-01
期刊：
影响因子：
1.7
通讯作者：
Tian, Yanhong
中科院分区：
文献类型：
--
作者：
Liu, Shugen;Deng, Bin;Tian, Yanhong
随着油气勘探技术和商业化程度的不断提高，油气藏的年龄和深度越来越受到世界各国的关注。本文研究了一个不对称的南北走向克拉通内凹陷，该凹陷发育于晚埃迪卡拉世至早寒武世。绵阳-长宁克拉通内凹陷宽约50 km，最陡处在盆地中心。特别是东部边缘显示其最大的陡峭度。凹陷演化可划分为五个阶段。它始于埃迪卡拉纪晚期，伴随着同湾运动的抬升和剥蚀。早寒武世麦地坪期发生了初始伸展作用，麦地坪组地层大量跨凹陷沉积。随后，在早寒武世的琼珠寺期发生了最大的伸展作用，导致凹陷内沉积了450-1700 m厚的麦地坪组-沧浪铺组。龙王庙期凹陷消失，被沉积物充填。克拉通内凹陷对灯影组、龙王庙组优质储层和牛蹄塘组烃源岩的发育具有重要影响。这表明，川中地区沿沿着克拉通凹陷成藏的可能性很大。
The older and deeper hydrocarbon accumulations receive increasing attention across the world, providing more technical and commercial challenges to hydrocarbon exploration. We present a study of an asymmetrical, N-S striking intracratonic sag which developed across the Sichuan basin, south China, from Late Ediacaran to Early Cambrian times. The Mianyang-Changning intracratonic sag is ~50 km wide, with its steepest part in the basin center. In particular the eastern margin shows its greatest steepness. Five episodes in the evolutions of the sag can be recognized. It begins in the Late Ediacaran with an uplift and erosion correlated to Tongwan movement. Initial extension occurred during the Early Cambrian Maidiping period, when more strata of the Maidiping Formation were deposited across the sag. Subsequently, maximum extension occurred during the Early Cambrian Qiongzhusi period that resulted in 450–1700 m thick Maidiping-Canglangpu Formations being deposited in the sag. Then, the sag disappeared at the Longwangmiao period, as it was infilled by the sediments. The intracratonic sag has significant influence on the development of high-quality reservoirs in the Dengying and Longwangmiao Formations and source-rock of the Niutitang Formation. It thus indicates that a high probability for oil/gas accumulation exists along the intracratonic sag, across the central Sichuan basin.