气窜速度计算方法探讨与应用

RESEARCH AND APPLICATION ON CALCULATION METHOD OF OIL AND GAS UPWARD VELOCITY

在油气勘探开发过程中,气窜速度不仅是油气储层活跃程度的反应,也是钻完井井控关键指标之一,现场气窜速度计算方法的科学选用对于钻完井施工效率和井控安全具有重要意义。对影响现场气窜速度计算方法的各种因素进行分析,指出目前现场采用迟到时间法存在的问题,考虑实际钻完井过程中的井身结构、钻具替排、气液相对滑脱作用、泵上水效率、录井数据延迟、后效起始点选择和归位井深等因素,采用优化后的替排液面复位法进行计算并进行现场应用。多口井应用结果表明该计算方法受泵冲不稳定、停开泵和静止时间短等因素影响较小,现场操作性强,计算结果更加接近实际值,特别是大幅提高了深井短起工况下的气窜速度计算精度,为现场下步施工提供了更为科学准确的参考依据。

In oil-gas exploration and development,oil and gas upward velocity is not only the reflection of the activity of reservoirs but also is the key parameter of well control,choosing the reasonable calculation method of oil and gas upward velocity is of great significance to operating efficiency and well control.Analyzing the various influences on calculation method of oil and gas upward velocity,pointing out the deficiencies in method of lag time,considering such factors as casing program,drilling tool displacement,relative slip between gas and fluid,pump efficiency,logging date delay,total gas hydrocarbon ascend point and outlet depth of gas,the calculation method of reductive volume displacement has been used and been performed field application.Application results of many wells show that this method is less affected by the factors such as unstable pumping,stop and start pumping and short static time.The calculated result is closer to the actual value,especially has improved the calculation accuracy of oil and gas upward velocity in deep wells,providing a scientific and exactly reference for well operation.