用空气造穴完井数据探讨煤储层压力

煤层气空气动力造穴完井技术在中国正处于探索和试验阶段,洞穴完井工艺可以获得丰富的煤储层数据。通过空气动力造穴完井观测数据,结合实际地质情况,将注气压力时间曲线分为两个阶段：注气压力小于储层压力时满足气体状态方程,注气压力大于储层压力时满足气体渗流方程,说明在注气初期井内压力与注气时间近似为直线关系,利用两直线的交点确定储层压力在理论上是合理的,并结合静态条件估算了储层压力。通过与注入压降试验结果对比,证明了计算结果的可信性。这一方法为综合评价储层条件和制定更合理的采排制度提供了有益的参考。

Discussion on Coal Reservoir Pressure Based on Well Aerodynamic Caving Completion Data

The CBM well aerodynamic caving completion technology is just under the exploring and testing stage in the country,abundant coal reservoir data can be obtained from the use of the technology.From the caving completion observed data,combined with actual geological condition,the air injection pressure-time curve can be divided into two stages： when the air injection pressure less than the reservoir pressure,it meets the equation of state;when larger meets the equation of seepage.It illuminates that during the initial injection stage,relation between pressure and time is near linear,using the intersection of two lines to determine reservoir pressure is reasonable theoretically,and then combined with static conditions estimates reservoir pressure.Through contrast of injection/drawdown test results,has verified the dependability of estimated results.The method can provide beneficial reference for comprehensive assessment of reservoir conditions and to establish a more reasonable production and drainage system.