Many interesting problems in the oil and gas industry face the challenge of responding to disturbances from afar. Typically, the disturbance occurs at the inlet of a pipeline or the bottom of an oil well, while sensing and actuation equipment is installed at the outlet, only, kilometers away from the disturbance. The present paper develops an output feedback control law for such cases, based on modelling the transport phenomenon as a 2 $\times$ 2 linear partial differential equation (PDE) of hyperbolic type and the disturbance as a finite-dimensional linear system affecting the left boundary of the PDE. Sensing and actuation are co-located at the right boundary of the PDE. The design provides a separation principle, allowing a disturbance attenuating full-state feedback control law to be combined with an observer. The results are applied to a relevant problem from the oil and gas industry and demonstrated in simulations.

Disturbance rejection in 2 x 2 linear hyperbolic systems

Boundary observer design for hyperbolic PDE-ODE cascade systems

An improved genetic algorithm optimization fuzzy controller applied to the wellhead back pressure control system

In this brief, a boundary control scheme is designed to suppress the vibration for a nonlinear drilling riser system. Considering the varying length, varying tension, and varying speed of the riser, the drilling riser is modeled as a moving Euler–Bernoulli beam system, which is described by a partial differential equation and four ordinary differential equations. Employing the Lyapunov’s direct method, boundary control is proposed to guarantee the closed-loop system being exponentially stable. Extensive numerical simulations are presented to show the effectiveness of the proposed control law.

Modeling and Vibration Control for a Moving Beam With Application in a Drilling Riser

In this paper, we use swapping design filters to bring systems of $n+1$ partial differential equations of the hyperbolic type to static form. Standard parameter identification laws can then be applied to estimate unknown parameters in the boundary conditions. Proof of boundedness of the adaptive laws are offered, and the results are demonstrated in simulations.

An Adaptive Observer Design for $n+1$ Coupled Linear Hyperbolic PDEs Based on Swapping

Automatic managed pressure drilling is an advanced pressure-control method which is intended to meet the increasingly high demands in drilling operations in the oil and gas industry. In this method, the circulating drilling fluid, which takes the cuttings out of the well, is released at the surface through a controlled choke. This choke is used for active control of the fluid pressure in the well. The corresponding automatic control system keeps the pressure at the bottom of the well at a specified setpoint despite various disturbances. One such disturbance, i.e., the vertical motion of the drill string, causes severe pressure fluctuations which need to be actively attenuated. In this paper, we present two different disturbance rejection strategies based on discretized partial differential equations for the well hydraulic system. The performance of the controllers is shown through simulations both under idealized conditions and on a high-fidelity drilling simulator.

Modeling and Control of Heave-Induced Pressure Fluctuations in Managed Pressure Drilling

Managed pressure drilling is an advanced pressure control method which is intended to meet increasingly high demands in drilling operations in the oil and gas industry. In this method, the circulating drilling fluid, which takes cuttings out of the well, is released at the surface through a controlled choke. This choke is used for active control of the fluid pressure in the well. The corresponding automatic control system keeps the pressure at the bottom of the well at a specified set-point despite various disturbances. One of such disturbances, vertical motion of the drill string, causes severe pressure fluctuations which need to be actively attenuated. In this paper we present two different disturbance rejection strategies based on discretized partial differential equations for the well hydraulic system. The performance of the controllers is shown through simulations both under idealized conditions as well as by simulations on a high fidelity drilling simulator.

Ingar Skyberg Landet

Papers

Modeling and Control of Heave-Induced Pressure Fluctuations in Managed Pressure Drilling

Control of heave-induced pressure fluctuations in managed pressure drilling

Modeling for MPD Operations With Experimental Validation