延安气田延气2-延128井区排水采气工艺技术研究

Study on Drainage Gas Production in Yanqi 2-Yan128 Well Area of Yan'an Gas Field

延安气田延气2-延128井区位于鄂尔多斯盆地伊陕斜坡中部偏南地区,目的层位包括石盒子组、山西组、本溪组,主力层为山23段,储层孔隙结构复杂,非均质性强,为典型的低渗砂岩气藏,具有低孔、低渗、低压、低丰度等特征。随着研究区勘探开发的不断深入,产水气井逐渐增多,区域稳产形势严峻,开展排水采气是延缓气藏水侵、解决气井积液、提高气藏采收率的有效方法。本文在研究区产水特征分析的基础上,结合各种排水采气工艺技术的优缺点,对其在研究区的适用性进行论证,优化给出了适合于研究区各种不同类型产水气井的排水采气技术。对比排水采气措施前后的预测数据,结果显示:排水采气措施可延长稳产期21个月,增产天然气量17.2亿m3,提高采出程度1.8%。

Yanqi 2-Yan 128 well area of Yan'an gas field is located in the south-central area of Yishan slope in Ordos Basin.The target layers include Shihezi Formation,Shanxi Formation and Benxi Formation.The main layer is Shan23 section.The reservoir pore structure is complex and the heterogeneity is strong.It is a typical low permeability sandstone gas reservoir with low porosity,low permeability,low pressure and low abundance.With the deepening of exploration and development in the study area,the number of water-producing gas wells has gradually increased,and the regional stable production form is severe.The development of drainage gas recovery technology is an effective method to delay the water invasion of gas reservoirs,solve the effusion of gas wells,and improve the recovery of gas reservoirs.Based on the analysis of the characteristics of water production in the study area,combined with the advantages and disadvantages of various drainage gas recovery technologies,this paper demonstrates its applicability in the study area,and optimizes the drainage gas recovery technology suitable for various types of water-producing gas wells in the study area.Comparing the predicted data before and after the drainage gas recovery measures,the results show that the drainage gas recovery measures can extend the stable production period by 21 months,increase the natural gas production by 1.72 billion cubic meters,and increase the recovery degree by 1.8%.