Chance Constrained Control for Minimizing Surge/Swab Effect in Oil-Well Tripping Operation
Herman Yoseph Sutarto1,a), Gilang Samudra Kuswana2,b), Singgih Satrio Wibowo3,c)

1Intelligent System, PT Pusat Riset Energi (PRE), Bandung, Indonesia
2Drilling System, PT Pusat Riset Energi (PRE), Bandung, Indonesia
3Aeronautical Engineering, Department of Mechanical Engineering, Politeknik Negeri Bandung, Indonesia

Abstract

This paper investigated convex chance constrained control of nonlinear dynamical system of axial motion of drill-string in oil well tripping operation. Stochastic nonlinear control framework is presented for control of the probability distribution of system state of axial velocities subject to probabilistic parametric uncertainties while ensuring the satisfaction of constraints in downhole pressure margin with some desired probability levels. The constraint is a nonconvex which greatly complicates the solution of optimization problems. To simplify a convex program, the convex bounding method is proposed and integrated with a robust estimator in order to simplify a convex program and to decrease the computational cost. The capability of stochastic control is demonstrated for tripping out activities with length of drill string 1000 m

Keywords: chance constraints, convex optimization, optimal control, tripping operations, surge- swab pressure

Topic: Energy engineering