以钻杆“准螺旋”状态模拟钻井液携砂状况

钻井过程中的钻柱状态，并非是无规则地贴附在井壁上．而是呈“准螺旋状”沿井眼轴线方向排列。分析了岩屑床形成的力学模型、水力学模型以及它们共同作用的模型，研究出了不同钻柱状态对钻井液流动的影响。在发生钻柱“准螺旋”状态的井段。钻井液所携带的岩屑更容易形成岩屑床。利用钻杆的“准螺旋状”性质，提出了一种模拟和预测钻井液在水平井与大斜度定向井井眼内携砂效果的新方法，根据该方法可判断钻井液携砂情况。并较准确地指出井眼内由于钻井液携砂不良而易于沉砂的位置。同时编制了相应的模拟软件。该软件结合渤海秦皇岛32—6平台的钻井实践进行了验证。获得了较满意的结果。

Simulating the transportation of cuttings with drill pipe‘similar spiral’modality

Drill pipe in drilling is not contacting well irregularly, but is similar spirally lining along the hole axis. The factors of influencing drilling fluid flowing regime in different drill pipe modality are investigated based on analysis of mechanics, hydraulics and mechanics-hydraulics models for cuttings beds formation, and the result shows that cuttings accumulates easily in the section where drill pipe modality of similar spiral exist. Therefore, a new method to simulate and predicate cutting transportation efficiency in horizontal and high angle directional wells has been presented by using drill pipe modality properties of similar spiral. With it, cuttings beds placing in borehole could be accurately found. The corresponding computer software has been developed and used in drilling practice on Qinhuangdao 32-6 platform. The results were better.