Research and Application on Optimization of Drainage Gas Recovery Methods in Linxing Block

Linxing block is a tight gas reservoir with low pressure and production. Water can be seen at the initial stage of production, so drainage gas recovery (DGR) measures are needed. In Linxing block, the selection of DGR technology mainly depends on field experience, and the low recovery rate is caused by strong subjective factors and unreasonable DGR. This paper summarizes the production evaluation table of each DGR, obtains the influence evaluation table of each DGR influence factor combined with the actual production situation, and obtains the weight of each influence factor by using the analytic hierarchy process. Finally, according to the membership function, the membership matrix between each DGR and the influencing factors is established, and the weight of each DGR is obtained by using the fuzzy comprehensive evaluation method. The larger the value is, the more suitable the DGR is. Thus, a set of DGR optimization model is established. The actual data of a well in Linxing block are verified. The example shows that the model can optimize the DGR according to the weight. Foam DGR in Linxing block is the best way, and optimizing tubing and screw pump are the second, and the gas lift is the most unsuitable. The results are consistent with the actual production in Linxing block.