龙女寺区块龙王庙组气藏试采效果分析评价

Analysis and Evaluation of Pilot Production Effect of Longwangmiao Formation Gas Reservoir in Longnvsi Block

川中龙女寺区块龙王庙组气藏与磨溪主体区具有相似的构造和沉积背景,是主体区之外最具勘探开发潜力的地区,是主体区重要的产能接替区。龙女寺龙王庙组气藏较主体区圈闭面积小、闭合高度低,滩体分散分布,非均质性强,且无统一气水界面,气水关系复杂。相比主体区生产效果及稳产能力较差,动态储量小,气井产能相对较低,产水机理不明确,试采阶段就有75%的气井产出地层水。龙女寺区块整体试采效果较主体区差的主要原因,一是储层地质条件不如主体区,非均质性较强;二是气井大部分产水,气水关系及水侵机理复杂,导致产能发挥受到影响。为此,提出有针对性的开发对策:深入开展气藏精细描述,刻画气藏地质特征;加强气藏动态监测,深化气水关系及水侵机理认识;开展水锁/水封关键因素研究,实施气井储层改造和工艺井,加密井网提高气藏采收率。

Longwangmiao Formation gas reservoir in Longnvsi Block in central Sichuan has similar structural and sedimentary background to main Moxi area,and is the area with the most exploration and development potential outside main Moxi area.As an important productivity replacement area in the main Moxi area,Longwangmiao Formation gas reservoir in Longnvsi Block has smaller trap area,lower closure height,scattered beach body,stronger heterogeneity,more complex gas-water relationship without unified gas-water interface.Compared with the main area,the production efficiency and stable production capacity is not so good with small dynamic reserves of gas reservoirs,relatively low productivity of gas wells.Water production mechanism is not clear,and formation water is produced from 75%of the gas wells in the pilot production stage of the gas reservoir.The main reason why the overall pilot production effect in Longnvsi Block is worse than that of the main area are:first,the reservoir geological conditions are not as good as the main area,and the heterogeneity is stronger;second,most of the gas wells produce water,and the gas-water relationship and water invasion mechanism are complex,resulting in the productivity being affected.Therefore,three targeted development strategies are proposed:first,in-depth detailed description of gas reservoirs is made to characterize the geolog-ical characteristics of gas reservoirs;Second,the dynamic monitoring of gas reservoirs should be strengthened and the understanding of gas-water relationship and water invasion mechanism of gas reservoirs should be deepened;Third,key factors of water-lock/water-seal are researched,reservoir reconstruction for the gas wells and process well are implemented,and well pattern is infilled to improve recovery of the gas reservoirs.