节点分析法在分层注气技术中的应用研究

Application of node analysis method in stratified gas injection

针对低渗透油藏注气开发需求,为实现储层的均匀动用,改善分层注气开发效果,采用节点分析法进行分层注气井工作制度的优化设计。文中应用采气实用计算理论,以注气井井底为节点,将注气系统划分为流入和流出2部分,分别建立了注气井垂直管流流入和地层渗流流出动态节点分析数学模型。以某油田H59区块4-2注气井为例,结合试注及吸气剖面资料,对各个小层进行了分层节点系统分析,得出不同井口注气压力下的最佳分层注气量,为下步分层注气提供了合理的建议。

According to the needs for gas flooding development of low permeability reservoirs, the method of node analysis was applied to design the stratified gas injection system for gas well to achieve uniform displacement and improve the effect of the reservoir. In this paper, the dynamic： mathematical models of the inlet flow in the vertical gas well and the outlet flow in the reservoir were established with practical enmputation theory of gas produetion, in which the down hole part was selected as a nude to divide the flowing system into two parts： inlet flow and outlet flow. Taking Well H59-4-2 in one oilfield as an example, the node system analysis was made for every single layer combined with iujection test and prnfile data. The optimum stratified injeetion rate was determined under different well-head injection pressures, which provided reasonable suggestions for stratified gas injection.