库车坳陷的油气运移全定量模拟

Quantitative Simulation of Hydrocarbon Migration in Kuqa Depression

为了给库车坳陷的油气勘探提供定量依据 ,使用盆地模拟软件BASIMS对该坳陷的地史、热史、成岩史、生烃史、排烃史及运聚史进行了全定量模拟 .其中油气初次运移的模拟使用简易而实用的方法 ,即 :对于油气初次运移 ,采用沉积压实渗流法求排油、物质平衡法求排气 ;对于油气二次运移 ,采用基于浮力驱动及达西定律的拟三维运聚模型 .除了讨论这些数值方法的敏感性参数 (参数敏感性与风险分析、排烃分配因子、断层及不整合面的渗透率、油气储集单元的确定 )外 ,给出了排烃史和运聚史的模拟结果 ,其聚集量的模拟结果不仅在数量上而且在位置上与实际情况符合 。

The histories of stratigraphic burial, geotherm, diagenesis, hydrocarbon generation, expulsion and migration-accumulation are simulated quantitatively by means of the basin modeling software of BASIMS in order to provide the quantitative data for oil and gas exploration in Kuqa depression. Of them, hydrocarbon primary migration is simulated by the easy and practical methods, i.e. sedimentary compaction-filtration method is used to calculate the amount of expelled oil and the mass balance method to calculate the amount of expelled gas. The pseudo 3-D migration-accumulation model based on buoyancy and Darcys Law is used to simulate on secondary hydrocarbon migration. The sensible parameters (parameter sensitivity and risk analyses, distribution ratio of hydrocarbons expelled, permeabilities in fault and unconformity zones, and determination of reservoir cell) in these numerical methods are discussed, and hydrocarbon expulsion and migration-accumulation histories have been simulated in detail. The modeling results are in agreement with the real pools not only on quantities but also on locations, and especially some predicted prospects have been proved by explorations later.