气体钻井地层出水定量预测模型研究

气体钻井地层出水定量准确预测是气体钻井可行性钻前论证的关键。目前,已有的出水量预测方法较少考虑气体钻井井底压差下地层渗流过程与地层应力变化的流固耦合作用对出水量的影响,在渗流力学和岩石力学的基础上,综合考虑地层渗流过程与岩石应力变化的流耦合作用对地层应力、孔隙度、渗透率以及孔隙压力的影响,建立气体钻井孔隙性地层和孔隙-裂缝性地层出水量预测动态流固耦合模型。结合工程实际,通过该模型计算得到气体钻井快速钻穿水层后出水量随时间的变化关系,计算结果与现场监测吻合。研究对于钻前准确预测出水量和筛选气体钻井层位具有重要意义。

Formation Water Quantitative Prediction Model Research in Gas Drilling

Gas drilling formation water accurate quantitative prediction is the key to the feasibility of gas drilling decision. At present, the existing water quantitative prediction methods did not take the influence of the fluid-structure coupling effect into consideration while water output under the pressure differential between the bottom hole and the formation. On the basis of seepage mechanics and rock mechanics, taking the influence of the fluid-structure coupling effect to formation stress, porosity, permeability and pore pressure into consideration, this paper established the dynamic fluid-structure interaction water quantitative prediction model for matrix formation and matrix - fracture formation in gas drilling. Combining with the engineering practice, with this model, the water quantitative production over time after penetrating the water formation was calculated, the calculation results coincide with the field monitoring. This Research has great significance to accurately prediction of water production and filtering of gas drilling feasible area before gas drilling.