四川盆地中南部地区中三叠统雷口坡组沉积相研究

Study on sedimentary facies of middle Triassic Leikoupo Formation of the southern area in Central Sichuan Basin

李德星 刘树根 张长俊 汪华 秦川

Li Dexing Liu Shugen Zhang Changjun Wang Hua Qin Chuan

成都理工大学油气藏地质及开发工程国家重点实验室, 四川成都 610059

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059

川中南部地区中三叠统雷口坡组划分为3个相(开阔台地相、局限台地相、蒸发台地相)、4个亚相(潮下、泻湖、潮间坪、潮上坪)和17个微相。沉积相横向上总体变化不大,岩性较统一,蒸发岩较发育,纵向上沉积相变化具有同步性。利用单因素法和优势相法,并结合层序地层学研究成果,把雷口坡组分为7个作图单元,较精确地展示了雷口坡组不同层段的沉积相展布和演化。研究区内雷口坡期的相对海平面升降变化和台地次级洼隆相间的古地貌共同控制着沉积相带展布和演化。雷口坡组以局限台地相为主,主要发育在雷一段1亚段的台内滩微相,为储集体有利的发育相带,多发育于潮间高处与泻湖的过渡区附近相对高能带。

The middle Triassic Leikoupo Formation of the southern area in Central Sichuan Basin may be divided into three facies (open platform, restricted plat form and evaporative platform), four subfacies (subtidal zone, lagoon, intertidal flat and supratidal flat) and 17 microfacies.The sedimentary facies of Leikoupo Format ion laterally changed little, and the lithology was unified.In this area, evaporate was well-developed horizontally, while longitudinally the sedimentary facies variation was synchronous in whole.By using the method of single factor analysis and dominant facies, and combining the outcomes of sequence stratigraphy research, Leikoupo Format ion is divided into seven mapping unit s,which relatively accurately exhibits the distribution and evolution of sedimentary facies.The relatively sea-level change and the microgeomorphology of alternating uplift and depressions in the carbonate plat form controlled the distribution and evolution of sedimentary facies.The Leikoupo Formation consists predominantly of restricted platform facies. The favorable facies belt to the forming of petroleum reservoirs is intraplatformal bank microface, which developed in the high-energy zones near the transitional zone between upper intertidal zone and lagoons in the 1st sub-member of the 1st member of Leikoupo Formation.

中国石油西南油气田分公司川中油气矿课题"川中南部地区中三叠统雷口坡组古岩溶分布及含气性储层研究"

https://doi.org/10.3969/j.issn.1008-2336.2010.01.036