考虑非达西效应的底水气藏见水时间预测方法

An Approach to Predict Water Breakthrough Time of Gas Reservoirs with Bottom Water in Consideration of Non-Darcy Flow

底水锥进是底水气藏在开发过程中遇到的一个重要问题,准确地预测底水锥进的时间对实际生产具有重要意义。对于底水气藏的高产气井,井底周围的表皮效应和气体高速非达西流动对气井的产能和见水时间都有很大影响。基于多孔介质中流体质点的渗流规律,综合考虑了气体非达西效应、表皮系数、打开程度以及日产气量等因素对见水时间的影响,推导出了底水气藏高产气井的见水时间预测公式。通过实例计算,并与其他方法比较,表明考虑了表皮效应和气体非达西效应的气井见水时间公式与朱圣举公式计算结果相近,相对误差为20.3%,该公式具有较好的实用性。

Water coning is an important issue in the development process of gas reservoirs with bottom water. Accurately predicting time of bottom water coning is of great significance to the actual production. For high produc-tion of gas reservoir with bottom water,skin effect surrounding downhole and non-Darcy flow have a significant im-pact on gas well productivity and bottom water coning time. Based on the theory of percolation flow through in por-ous media, and considering influence of the factors such as the gas non-Darcy effects, skin factor, affect the degree of opening and daily gas production for water coning time of gas reservoirs with bottom water, water coning time of gas reservoirs with bottom water was deduced. Compared to results of other methods, example shows that water breakthrough time calculation which takes into account the skin effect and gas wells non-Darcy effects is close to the calculation of zhu shengju’ s method,and the method in this paper is more realistic.