五宝场构造沙溪庙组气藏动态特征分析与开采思路

DYNAMIC CHARACTERISTICS ANALYSIS ON WUBAOCHANG STRUCTURE OF SHAXIMIAO FORMATION GAS RESERVOIRS AND SOME IDEAS ABOUT ITS EXPLOITATION AND PRODUCTION

五宝场构造沙溪庙组气藏是川东北地区第一个投入整体勘探开发的浅层河湖相砂岩气藏,要确保气藏科学、合理、高效地开发,为气藏开发方案的编制提供可靠的依据,就必须对该气藏动态特征进行分析、总结和研究。为此,通过初期试采动态特征和动态监测资料分析认为,五宝浅2-1井井区的3口井是连通的,且连通性较好;而其他井区的连通关系则有待继续监测证实;五宝场构造沙溪庙组气藏目前未发现地层水,现有钻井控制范围内无可动水存在;各井H2S含量极微,CO2含量较低,该气藏天然气总体属于优质烃类气。进而提出了下一步气藏开采思路:根据气井实际生产情况,逐步调整气井产能,拟定气井生产方式,摸索科学、合理的生产制度;运用气藏动态监测技术,摸清气藏的动态特征;定期进行生产动态分析,确保气藏正常生产;针对沙溪庙组纵向上分布有多套砂体、多个产气层的特点,进行综合研究,选择新层的有利部位部署井位,从而提高气藏产量。

The Shaximiao Formation gas reservoirs in the Wubaochang structure is a kind of shallow fluviolacustrine facies sandstone gas reservoirs, which was explored and developed as a whole for the first time in Northeast Sichuan Basin. In order to extract the gas reservoirs in scientific, reasonable, and high-efficient way, and provide reliable references for setting out a good plan on exploitation, the gas reservoirs performance should be analyzed, summarized and studied as well. Through studying on the monitoring data and the features on gas reservoirs from the initial recovery, it was found out that three wells in the Block Wubao Qian well 2-1 were interconnected with high connectivity, whereas the similar feature of which about the other wells in the other Blocks needed to be testified by later monitoring. In the Shaximiao Formation gas reservoirs, no formation water has been found, neither the movable water found while drilling so far. Natural gas in the gas reservoirs was thought to be a kind of good-quality nonassociated gas with less H2S and low-content CO2 discovered in the gas wells. Some suggestions on next-step exploitation were put forward in detail as follows: ①Reasonable and scientific rules and regulations during the production should be set down, the operation style of a gas well should be determined and the production capacity ought to be adjusted according to its actual production; ②The performance on the gas reservoirs should be under control by use of monitoring techniques on gas reservoirs; ③The normal production for the gas reservoirs should be ensured by regular analysis on production behaviors; ④After comprehensive study on the features of the Shaximiao Formation which are characterized by multiple sets of sand bodies and multiple gas-production layers in the vertical direction, well locations should be deployed on the favorable parts of the new formation in order to enhance the yield of the gas reservoirs.