断层静止期垂向封气性评价标准的物理模拟实验及其应用

PHYSICAL SIMULATION EXPERIMENT OF THE EVALUATION STANDARD OF VERTICAL GAS- SEAL ABILITY OF FAULT AT MOTIONLESS STAGE AND ITS APPLICATION

为了建立静止时期断层垂向封气性评价标准,利用物理模拟实验结果,建立了断层静止期天然气沿断裂带运移速度与粘土含量之间的变化关系,根据此关系确定出了静止期断裂带在不同条件下封闭天然气所需泥质含量下限值。利用断移地层岩性及断距预测了断裂带中泥质含量。通过断裂带泥质含量与断裂带封闭天然气所需泥质含量下限值的比较,建立了一种静止时期断层垂向封气性的研究方法。并将其应用于库车坳陷克拉2气田F1断层垂向封气性的研究中,评价结果与F1断层对天然气所起作用的实际作用相符,表明该方法用于断层垂向封气性评价是可行的。

In order to set up the evaluation standard of vertical gas-seal ability of fault at motionless stage, the relation between the gas migration velocity along fault zone at fault-motionless stage and the shale content in fault zone was established by use of physical simulation experimental results. The shale content cutoff needful for sealing gas under different conditions at fault-motionless stage was determined according to this relation. The shale content in fault zone was predicted by the lithology of the faulted strata and by the fault throw. The method of studying the vertical gas-seal ability of fault at motionless stage was established by contrasting the shale content with its cutoff. Through evaluating the vertical gas-seal ability of fault F 1 in Kela - 2 gas field of Kuche Depression by this method, it was shown that the result is identical to the actual role of fault F1 in gas migration and accumulation. Therefore the method is feasible.