利用压力激动响应判识水平井来水方向的选井决策

Water injection well selection for identifying direction of water by horizontal well pressure excitation

在特低渗透裂缝型油藏多段压裂水平井注水开发过程中,受储层非均质性、天然裂缝与人工裂缝等因素影响,水平井多方向、跨井距见水问题突出。通过注采井网油水井间压力激动响应分析判识油井来水方向,将为后期油水井双向调堵提供重要依据。为了探索水平井压力激动判识来水方向的注水井选井方法,解决注水井全覆盖监测工作量大、成本高的问题,通过建立裂缝型油藏井间连通物理模型,运用井间单元物质平衡方程求解井点压力值,在压力拟合基础上,计算井间连通系数(传导率),实现注采井间连通程度的定量表征,最终创建了流压拟合选井决策方法。现场注采井组实例计算结果显示,该方法能够准确定位水平井裂缝连通注水井,达到判识来水方向的目的。

In the process of water injection development of multi-stage fracturing horizontal wells in ultra-low permeability fractured reservoirs,due to factors such as heterogeneity,natural fractures and artificial fractures,water seepage problems in horizontal wells in multiple directions and spans are prominent.The analysis of pressure excitability response between oil and water wells to identify the direction of oil well inflow will provide an important basis for the two-way plugging control of oil and water wells.In order to explore the method of horizontal well pressure excitement to identify the direction of the water injection well,and to solve the problem of large workload and high cost of the full coverage monitoring of the water injection well,by establishing a physical model of inter-well connectivity in fractured reservoirs,the inter-well unit mass balance equation was used to solve the well point pressure value.On the basis of pressure fitting,the inter-well connectivity coefficient(conductivity)was calculated to achieve quantitative characterization of the degree of connectivity between injection and production wells,and finally a fluid pressure fitting well selection decision method was created.An example of the on-site injection-production well group calculation showed that it could accurately locate the horizontal well fractures connected to the water injection well,so as to achieve the purpose of identifying the direction of water inflow.