大涝坝凝析气藏考虑多孔介质影响的衰竭开采相态特征

摘要

As for the porous media effects on dew point pressures, component changes and condensate recovery ratio of well DLK 4 in gas condensate reservoir of Dalao dam, the effects of porous media on fluid recovery behavior were evaluated and compared with the PVT cell depletion experiment results to guide oil field development. Studies show that the fluid dew point pressure changes are not obviously affected by porous media. The component changes in constant volume depletion process show that due to porous me-dia, C1 desorb into gas phase, C7+get into liquid phase, while C3 get into liquid phase and gas phase simultaneously. Meanwhile, un-der the influence of porous media, liquid mole fraction increases about 5%, the maximum anti-condensate saturation adds 5.5%, and condensate recovery reduces by 3%with the decline to 10 MPa. Thus, during the gas condensate reservoir depletion process, the impact of the porous media must be considered.%考虑多孔介质对大涝坝凝析气藏DLK4井露点压力、组分变化及凝析油采收率等的影响，评价多孔介质对流体开采特征的影响，并与PVT筒中的衰竭实验结果进行比较，以指导油田开发。实验研究表明：考虑多孔介质的影响时流体露点压力变化不明显；定容衰竭过程中的组分变化显示考虑多孔介质的影响时脱附出的C1主要进入气相，C7+主要进入液相，而C3则同时进入液相和气相；同时在多孔介质的影响下，液相摩尔分数增加约5%，最大反凝析液饱和度增加5.5%，而衰竭到10 MPa时，凝析油采收率降低3%。因此，在凝析气藏衰竭开采过程中必须考虑多孔介质的影响。