有水气藏开发早期可采储量的评价方法

Recovery Prediction for Water-driven Gas Reservoirs in the Early Stage of Development

有水气藏是天然气藏中的一个基本气藏类型 ,其采收率受多种因素的影响 ,如地面集输压力、井筒混合气水流动的液柱压力和储层物性等 ,目前普遍采用经验取值、物质平衡和气藏数值模拟等方法进行研究 ,但由于受开发评价阶段试采资料偏少和气藏数值模拟无法模拟井筒流动等因素的影响 ,早期采收率计算往往偏差较大 ,针对这些问题 ,从气田开发一体化的特点出发 ,提出了一种全面考虑地层→井筒→地面流动条件下 ,有水气藏 (含凝析有水气藏 )的废弃压力的计算方法 ,发展了利用物质平衡早期预测有水气藏采收率的理论 ,方法可靠、适用性强 。

The recovery of water driven gas reservoirs is dependent on many factors, such as the minimum entrance pressure to gathering pipelines, wellbore liquid head pressure loss for gas water mixed flow, and reservoir properties. During the early stage of development, empirical equation, material balanced equation, and reservoir simulation are used to predict the reservoir recovery, but the predicted recoveries are often very optimistic because of the absence of necessary reservoir performance data and the failure of the simulation model to calculate the wellbore mix flow. In this paper, a method of abandonment pressure calculation is given for water driven gas reservoirs(including water driven gas condensate reservoirs), which incorporates all factors affecting recovery during reservoir→wellbore→surface flow. Based on the material balanced equation for water driven gas reservoirs, the new equations are tested to be reliable and can be used widely.