用钻柱“准螺旋”性质预测井眼沉砂段位置

PREDICTION OF SAND-SETTLED HOLE INTERVAL BY USING "QUASI-SPIRAL PROPERTY" OF DRILLING STRING

作者利用有限元方法开发了一种计算机程序 ,模拟滑动钻井时井眼钻柱的弯曲形状 ,以钻柱的“准螺旋”理论来判断钻井液在这一井段携砂的难易程度。并结合流体力学方法 ,预测严重沉砂井段及一般沉砂井段的位置。这种预测方法可以作为钻井时防止井下事故的辅助手段之一。程序在海上油田进行了验证 ,获得了较满意的结果。

The authors have developed a compu ter program by use of the finite element method,which can determine the proppant carrying capacity of the drilling fluid in some hole interval by use of 'quas i spiral property' of the drilling string and through simulating the drill ste m buckling form when sliding drilling is being conducted,and the place of grievo us and common sand settled hole interval can be predicted through combination w ith fluid mechanics method.This prediction method can be used as one of the auxi liary measures used for preventing downhole accidents while drilling.The program has been tested and verified in the offshore oil field,obtaining a satisfactory result.This program was applied for invention patent to the state.