Automatic control of managed pressure drilling

Abstract

Managed pressure drilling (MPD) has emerged as a powerful technology for safe and efficient drilling of hydrocarbon wells. However, it poses interesting control challenges that must be addressed before the anticipated impact. These challenges stem from the strongly multivariable nature of the problem, the presence of critical constraints, and the inherent uncertainty in both models and measurements. In this work we give a brief overview of managed pressure drilling, and make the case that model predictive control is a natural approach to controlling MPD. We demonstrate the proposed approach on an example of model predictive control application to dual-gradient drilling, a particular variant of MPD.Øyvind Breyholtz and Gerhard Nygaard are with the International

Feedback control of proppant bank heights during hydraulic fracturing for enhanced productivity in shale formations

“…We want to note that over the last 10 years, the oil and gas production industry has applied model predictive control (MPC)-based algorithm to drilling processes to enhance pressure control flexibility and process safety. [48][49][50][51][52][53][54][55][56][57][58][59] However, its application to hydraulic fracturing has not received much attention because of (a) limited availability of real-time measurements, (b) presence of uncertainties in the measurement data, and (c) large computational requirements due to the dynamic simulation of highly coupled PDEs defined over a time-dependent spatial domain.…”

Challenges of Modeling Drilling Systems For the Purposes of Automation and Control

“…Managed pressure drilling (MPD) is providing a rich source of problems and challenges for the control systems community, Breyholtz (2010), Fredericks (2008), Geehan (2010) and Stamnes (2011). The base-line objective is to control the bottom-hole pressure (BHP) in the face of all Copyright held by the International Federation of Automatic Control disturbances.…”

Model predictive control and estimation of managed pressure drilling using a real-time high fidelity flow model

“…Nevertheless, a simplified model is often accepted for use in the MPC in order to address practical limitations relating to such things as incomplete understanding of the physical process, limited computational power, or inadequate availability of expertise for control system maintenance, often trading optimal process control for usability [13]. Indeed, in many MPC applications, models include simplifications of some type, such as reduction in model order or linearization of significant nonlinear processes (see [9,10,14,15,16,17,18,19]). The simplest of these models may be termed gray box models, which incorporate linear transfer function models and nonlinearity blocks to describe relationships between manipulated variables and system behavior.…”