Method and apparatus for monitoring of downhole dynamic drag and torque of drill-string in horizontal wells
Method and apparatus for monitoring of downhole dynamic drag and torque of drill-string in horizontal wells
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DOI：
10.1016/j.petrol.2018.01.077
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发表时间：
2018-05
影响因子：
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通讯作者：
Yang Liu;Tianshou Ma;Ping Chen;Chuan Yang
中科院分区：
文献类型：
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作者：
Yang Liu;Tianshou Ma;Ping Chen;Chuan Yang
井下阻力和扭矩的监测与控制是水平井钻井技术中一个永恒的研究课题，但其理论和经验尚处于探索阶段。在这项工作中，提出了一种包括井下参数测量系统和钻柱有效重量计算模型的综合动态监测方法，以发现井下阻力和扭矩。在Visual Basic环境下编制了计算程序。以T2-4-22H1井为例，利用研制的井下参数测量仪(DPMA)进行了井下实验，获得了井下钻压(DWOB)和井下扭矩(DTOB)。实验结果验证了该方法的可行性和适用性。结果表明，在滑动模式下测得的表面钻压明显低于记录的表面钻头重量。结果表明，井下阻力明显大于地面阻力。在旋转模式下，虽然钻压和拖拉力在地面和井下没有显著差异，但钻柱旋转会产生过大的摩擦力矩。讨论了造成地面和井下参数差异的主要原因。根据测得的井下参数，反演了不同钻井方式下摩阻系数的变化规律。该方法可为水平井安全高效钻井提供有力的技术支持。
Monitoring and control downhole drag and torque is a eternal research topic in horizontal drilling technique, but the theory and experience are still in the exploring stage. In this work, an integrated dynamic monitoring method, including a downhole parameters measuring system and a model for calculating the effective weight of drill-string, is proposed to discover the downhole drag and torque. A computational program is developed in the Visual Basic environment. Taking well T2-4-22H1 as an example, the downhole experiment are conducted to obtain downhole weight-on-bit (DWOB) and downhole torque-on-bit (DTOB) by using the developed downhole parameters measuring apparatus (DPMA). The experiment results are utilized for verifying the feasibility and suitability of the present method. The results show that the measured DWOB is significantly lower than the recorded surface weight-on-bit (SWOB) under sliding mode. As a result, the downhole based drag force is obviously higher than that based on surface data. For rotary mode, though the weight-on-bit and drag force do not make significant difference on both surface and downhole, but excessive frictional torque is generated due to drill-string rotating. The main reasons caused the diversity of surface and downhole parameters are discussed. Additionally, based on the measured downhole parameters, the changing rules of friction coefficient under different drilling modes are inversed. The present drag and torque monitoring method can provide a powerful technical support for the safe and high-efficiency drilling of horizontal wells.