川东地区五百梯构造天然气运聚成藏史模拟研究

利用二维盆地模拟软件BasinMod 2 D对四川盆地东部地区五百梯构造石炭系天然气的运聚成藏史进行了模拟。剖面模拟研究表明 ,志留系烃源岩分别于 2 10Ma前和 171Ma前开始进入生油、气门限 ,在 180～16 5Ma及 16 9～ 15 9Ma时处于生油、气高峰 ;于 175Ma前及 16 7Ma前进入排油、气门限 ,在 170～ 15 0Ma和16 6～ 16 1Ma处于排油、气高峰阶段。气藏内的油气运聚史可分为 3个阶段 :第一阶段为 172～ 16 5Ma ,原油首先在古隆起中聚集 ,形成古油藏 ;第二阶段为 16 5～ 16 0Ma ,源岩排出的天然气驱替已聚集的原油 ,形成古油气藏 ;第三阶段为 15 0～ 135Ma,原油裂解为天然气 ,形成古气藏

MODELING OF MIGRATION AND ACCUMULATION OF GAS IN WUBAITI STRUCTURE IN THE EAST OF SICHUAN PROVINCE

The processes of hydrocarbon generation, migration and accumulation in Wubaiti structure in the east of Sichuan Province were modeled by means of Basin Mod 2\|D modeling software developed by Platte River Associates Company. In the simulated section, the source rock of Devonian came into the thresholds of oil and gas generation at 210 Ma and 171 Ma. The main periods are ranged from 180 Ma to 165 Ma for oil generation, and from 167 Ma to 159 Ma for gas generation respectively. The expulsion of oil and gas from source rock began at 175 Ma and 167 Ma, and the main expulsion periods are ranged from 170 Ma to 150 Ma for oil and from 166 Ma to 161 Ma for gas. The accumulation of hydrocarbon can be divided into three stages. The first stage was from 172 Ma to 165 Ma when oil was accumulated in the uplift and oil reservoir formed. The gas expulsed from source rock replaced the oil partly, and oil and gas co\|existed in reservoir in the second stage from 165 Ma to 160 Ma. Finally oil was totally replaced by gas cracked from oil in the reservoir and the gas pool formed.