塔里木盆地阿瓦提地区碎屑岩领域成藏特征分析

Characteristics of clastic rock reservoir accumulation in Avat area of the Tarim Basin

耿锋 顾伟欣

Geng Feng Gu Weixin

中国石化西北油田分公司, 乌鲁木齐 830011

Research Institute of Exploration & Production, SINOPEC Northwest Company, Urumqi, Xinjiang 830011, China

通过对阿瓦提地区重点钻井不同层段的岩心进行流体包裹体分析,揭示古生界-新生界碎屑岩储层存在油气的充注过程,其中志留系存在加里东晚期、海西晚期及喜马拉雅期3期充注,泥盆系存在海西晚期及喜马拉雅期2期充注,三叠系及古近系存在喜马拉雅晚期1期充注。由于圈源不匹配、缺失与油源相通的断裂或保存条件差,均未形成油气藏。综合烃源岩及构造演化史,认为环阿瓦提断陷与古隆起的过渡部位,古生界碳酸盐岩和碎屑岩具备形成原生油气藏、中新生界碎屑岩具备形成次生油气藏的条件,具备通源断裂的地层-岩性圈闭是有利的勘探目标。

Through the analyses of reservoir rock fluid inclusions in different layers of important drilling wells in Avat area of the Tarim Basin, we found that hydrocarbon charges had occurred in the Paleozoic-Cenozoic clastic reservoirs. For the Silurian reservoirs, hydrocarbon charges took place during the late Caledonian, the late Hercynian, and the Himalayan. For the Devonian reservoirs, there were two charging periods:the late Hercynian and the Himalayan. For the Triassic and Paleogene reservoirs, hydrocarbon charges took place during the late Himalayan. However, reservoirs failed to form due to the poor matching relation between hydrocarbon source and traps, poor preservation conditions, and the missing of hydrocarbon migrating faults. The analyses of source rocks and tectonic evolution history showed that, the Paleozoic carbonate and clastic rocks formed primary oil and gas pools while the Mesozoic clastic rocks formed secondary oil and gas pools in the transition zone between the Awat Sag and palaeo high. Stratigraphic and lithologic traps with oil source faults are favorable exploration targets.

https://doi.org/10.11781/sysydz2015S1010