Title
Dynamic optimization for robust path planning of horizontal oil wells
Abstract
This paper considers the three-dimensional path planning problem for horizontal oil wells. The decision variables in this problem are the curvature, tool-face angle and switching points for each turn segment in the path, and the optimization objective is to minimize the path length and target error. The optimal curvatures, tool-face angles and switching points can be readily determined using existing gradient-based dynamic optimization techniques. However, in a real drilling process, the actual curvatures and tool-face angles will inevitably deviate from the planned optimal values, thus causing an unexpected increase in the target error. This is a critical challenge that must be overcome for successful practical implementation. Accordingly, this paper introduces a sensitivity function that measures the rate of change in the target error with respect to the curvature and tool-face angle of each turn segment. Based on the sensitivity function, we propose a new optimization problem in which the switching points are adjusted to minimize target error sensitivity subject to continuous state inequality constraints arising from engineering specifications, and an additional constraint specifying the maximum allowable increase in the path length from the optimal value. Our main result shows that the sensitivity function can be evaluated by solving a set of auxiliary dynamic systems. By combining this result with the well-known time-scaling transformation, we obtain an equivalent transformed problem that can be solved using standard nonlinear programming algorithms. Finally, the paper concludes with a numerical example involving a practical path planning problem for a Ci-16-Cp146 well.
Year
DOI
Venue
2016
10.1016/j.amc.2015.11.038
Applied Mathematics and Computation
Keywords
Field
DocType
Switched system,Parameter optimization,System sensitivity,Horizontal well,Time-scaling transformation
Motion planning,Mathematical optimization,Momentum (technical analysis),Curvature,Path length,Control theory,Nonlinear programming,Sensitivity (control systems),Optimization problem,Dynamical system,Mathematics
Journal
Volume
ISSN
Citations 
274
0096-3003
0
PageRank 
References 
Authors
0.34
2
4
Name
Order
Citations
PageRank
Zhaohua Gong1225.31
R.C. Loxton213016.50
Changjun Yu3788.67
K. L. Teo41643211.47