川西白云岩储层酸化对流体与储量的影响

The Effect of Acidification on Fluid and Reserves of Dolomite Reservoir in the Western Sichuan

川西雷口坡组白云岩储层埋藏深、天然气成藏规模巨大。白云岩储层不均质性强,需要酸化压裂才能获得好的产能。但储层酸岩反应对地层水与天然气样品产生影响,将影响到储层评价、储量计算。从白云岩储层特征、酸岩反应工艺与原理、流体样品分析与采用、酸岩反应实验与分析出发,论证了白云岩酸岩反应对流体影响分析。剔除明显酸岩反应影响样品外,若不剔除受酸岩反应影响流体样品,将使天然气中烃类气储量计算比实际降低10.82%。川西气田储量计算运用本研究成果采用真实样品,保证了储层评价与储量计算的准确,同时也对白云岩储层储量计算研究具有实践意义。

The dolomite reservoir of Leikoupo Formation in Western Sichuan is deeply buried and the scale of natural gas accumulation is huge.Dolomite reservoir is highly heterogeneous and needs acid fractured to obtain good productivity.However,reservoir acid rock reaction has an impact on formation water and natural gas samples,which will affect reservoir evaluation and reserve calculation.Based on the characteristics of dolomite reservoir,acid rock reaction process and principle,fluid sample analysis and application,acid rock reaction experiment and analysis,the influence of dolomite acid rock reaction on fluid was demonstrated.Excluding the samples obviously affected by acid rock reaction,if the fluid samples affected by acid rock reaction were not removed,the calculated hydrocarbon gas reserves in natural gas would be reduced by 10.82% compared with the actual reserves.The reserve calculation of West Sichuan gas field used the research results and real samples to ensure the accuracy of reservoir evaluation and reserve calculation.The research also had practical significance for the reserve calculation of dolomite reservoir.