利用流动物质平衡确定低渗气藏单井控制储量

FLOWING MATERIAL-BALANCE METHOD TO DETERMINE CONTROLLED RESERVES OF SINGLE WELL IN LOW-PERMEABILITY GAS RESERVOIRS

物质平衡方程计算动态储量已被广泛地应用于气藏开发研究中,但该方法对地层压力精度要求较高,地层压力准确与否直接影响储量计算结果的准确度。在低能量储层及致密气层中,常规的试井测压要测得准确的地层压力需要较长的关井时间,会影响到气藏的正常生产。当气井进入拟稳定流状态后可以利用流动物质平衡对气井单井动态控制储量进行计算,该方法主要依据容易获得的井口压力,较好的解决了地层压力资料较少情况下动态储量的计算问题。在应用物质平衡法计算低渗透气藏动态控制储量时,为避免认识上的偏差和计算结果的失真。应该首先判断流动是否达到拟稳定流,并应用拟稳定以后的数据进行分析,不能笼统地将所有数据点回归为一条直线。

Material-balance method to calculate dynamic reserves has been widely applied to reservoir development.However,it requires highly accurate formation pressure,which can affect directly calculated reserves.In low-energy and tight gas reservoirs,a longer shut-in time is needed to obtain an accurate formation pressure even though this time may affect a normal production.Under the state of pseduosteady flow,the dynamic controlled reserves of single well can be calculated by flowing material-balance method.In spite of few formation-pressure data,this method can calculate dynamic reserves based on easily obtained wellbore pressure.To avoid some errors during this calculation,we should estimate whether the flow is under the pseduosteady state,and use some data after pseduosteady flow to carry out an analysis.