中文摘要：

为了避免起下钻过程中井涌、井漏等复杂情况的发生,需要提高井筒波动压力计算精度。以槽流模型为基础,结合起下钻过程中的流体真实速度分布情况,根据井筒流体的连续性及相应的边界条件,分别讨论层流、紊流状态下的波动压力,建立了基于钻柱运动的稳态井筒波动压力计算模型,并采用数值解法对模型进行求解。结合现场生产数据分析发现：当起下钻速度由0.2 m/s增大至0.6 m/s时,波动压力由0.21 MPa增大至0.27 MPa;钻柱运动速度、流体流变性等条件不变,环空内外径之比由0.55增大至0.95时,井筒波动压力增加幅度由0.30 MPa增大至0.50 MPa。采用文献数据进行计算对比,结果表明：Burkhardt模型的计算误差多数大于8%,波动压力模型预测值与实测值的计算误差基本小于5%,符合精细控压钻井计算误差要求。研究结果表明,采用井筒稳态波动压力计算方法可以精确分析非钻井过程井筒压力,指导现场安全生产。

英文摘要：

To eliminate the possibility of kicks,lost circulation and other complicated situations during tripping operations,it is necessary to enhance the accuracy of calculation for the wellbore fluctuation pressure.Based on the slot flow model and considering the actual velocity distribution in the wellbore,fluctuation pressure at laminar flows and turbulence flows was investigated in accordance with the continuity of wellbore fluids and corresponding boundary conditions.Eventually,steady fluctuation pressure calculation methods were established and numerical solutions were also introduced.Field production data were used to verify these models.When the velocity of the drilling string was increased from 0.2m/s to 0.6m/s,fluctuation pressures increased from 0.21 MPa to 0.27 MPa.Under stable drilling strings velocity and fluid rheology,fluctuation pressure of the wellbore increased from 0.3MPa to 0.5 MPa when ID/OD ratio increased from 0.55 to 0.9.Through comparison with experiment data in published literatures,calculation errors from the Burkhardt model was over 8%,while the calculation error from the new model was less than 5%.The new model met pressures accuracy requirements in drilling operations.Research results show that the high-precision steady fluctuation pressure calculation method could be used for accurate analysis of wellbore pressures during non-drilling operations and might provide necessary guidance for secure operation onsite.