Pressure wave propagation in Managed Pressure Drilling model comparison with real life data

Abstract

Drilling for oil and gas is a complex process, involving pumping of fluid through kilometers of pipes. Even though the drilling fluid has a high speed of sound (≈1000 m/s), the large lengths involved make pressure wave propagation significant in timescales where such phenomena can usually be neglected in other processes. Managed pressure drilling, a technological extension of conventional drilling, adds a choke on the return flow from the drilling process. Significant work has been done in recent years on creating a simplified model of the process, often by neglecting distributed dynamics, and using this for controller design. This paper compares the simplified model most often used, with a distributed partial differential equation (PDE) model and compare the performance with measured data for wave propagation while doing managed pressure drilling. Fluid structure interaction and theoretical vs recorded speed of sound are discussed.

Modeling and Numerical Implementation of Managed-Pressure-Drilling Systems for the Assessment of Pressure-Control Systems

“…These effects may be modelled in terms of uncertainties in the system parameters. Effects such as well expansion can also be approximately lumped into the system parameters, see,e.g., (Berg et al 2019b).…”

Model complexity reduction and controller design for managed pressure drilling automation

“…This formulation of the closed-loop dynamics clearly illustrates a type of separation principle, implying that the exponential stability of the error dynamics in (37) guarantees the exponential stability of the closed-loop system. We exploit this fact to design L 1 and L 2 independently of K sf .…”

“…We should expect this similarity because of the good accuracy of the approximate model. To implement the PDE model, we have discretized it using a staggered-grid discretization scheme, see, e.g., [37]. At the same time, we also apply the controllers in ( 43) and (45) to Σ for the sake of a comparative study.…”