底水气藏气水分层开采技术

Zoning Production Technique of Gas and Water in Gas Reservoirs with Bottom Water

底水锥进会造成气藏产量下降,气井水淹,采收率下降。通过双层完井,采用气水分层开采方法,使气水界面上的天然气通过油套环空排出,气水界面下的水则通过油管抽出,此法可以抑制气井水锥,使气井产量不受底水锥进临界产量限制,增加气井产量,提高气藏采收率。对气井排水消锥的原理进行了分析,用数学解析式计算了消除水锥时生产井的合理气水产量比,为底水气藏开发提供理论指导。气水分层开采技术适用于对底水分布认识比较清楚,同时气水界面比较明显的底水气藏。

Bottom water coning would cause gas production decline,water flooding in gas wells and decrease of gas recovery factor.Dual completion technology and gas-water zoning production method were used to drain the gas through tubing-casing annulus,the gas below the gas-water interface was released through tubings,it can be used to restrict water coning in gas wells,thus production in the gas wells would not restricted by water coning and production was raised in the gas wells,thereby the recovery factor of the gas wells was enhanced.The principle of water drainage and coning removal in the gas wells are analyzed,a mathematical analytical equation is used to calculate rational gas-water production ratio in producing wells as water coning is removed,it provides a theoretical guidance for gas reservoirs with bottom water.The gas-water zoning production method is suitable for production in the gas reservoirs with clear understanding of bottom water distribution and obvious gas-water interface.