Open Access

ARTICLE

On Improving the Accuracy of Prediction of the Down-hole Drag & Torque in Extended Reach Drilling (ERD)

Deli Gao^1,2, Lianzhong Sun^1,3, Hongshu Wei⁴, Shunwen Wang⁴

1 Key Lab of Petroleum Engineering in the Ministry of Education, China University of Petroleum, Beijing 102249, China.
2 Corresponding author: Deli GAO. E-Mail: gaodeli@cup.edu.cn
3 Sinopec Research Institute of Petroleum Engineering, Beijing 100101, China.
4 CNOOC China Limited-Shenzhen, Shenzhen 518067, China.

Computer Modeling in Engineering & Sciences 2012, 89(2), 143-162. https://doi.org/10.3970/cmes.2012.089.143

Abstract

Due to the complexity of forces acting on the down-hole tubular strings in extended reach drilling (ERD), the factors which influence the process should be taken into account as much as possible, in order to predict the down-hole drag & torque more accurately. This can help us to identify and prevent the problems related to downhole drag & torque in ERD. The effects of such factors, as the tubular buckling, the buoyancy, the mechanical resistance and the friction reducer, on down-hole drag & torque, are taken into account in this paper, in order to improve the accuracy of the prediction of the drag and the torque In addition, the optimization problem for controlling the down-hole drag & torque is solved in this paper. The optimum placement of the friction reducers is determined, in order to minimize the down-hole drag & torque, while allowing for a moderate contact between down-hole tubular and wellbore. The consideration of the mentioned effects, and the control methods presented, were used for the optimization analysis of down-hole drag & torque and the drilling operation, in extended-reach drilling. Interpretation of the field data provides us with an insight into the down-hole drag & torque computations.

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Keywords

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