Case Study: First Experience of Developing an Influx Management Envelope IME for a Deepwater MPD Operation

Abstract

Abstract The Influx Management Envelope (IME) proposed by Culen et al. (2016) is an advanced, innovative way to assess influx conditions in Managed Pressure Drilling operations, offering an improved tool for the decision making process. This work presents the process of developing the IME concept on a real deepwater MPD operation for the first time. Limiting factors such as: shoe integrity, maximum surface pressures, and mud gas separator (MGS) flow rates (gas and liquid) have been taken into consideration in the process of developing a set of Influx Management Envelopes for three different hole sections. Two methods were used for developing the IMEs: Single bubble approach, as described by Culen et al.; and hydraulic modeling using a commercial transient, multiphase flow simulation software package. A comparison of the results from the single bubble calculation versus simulation methods is presented, highlighting the impact of gas dissolution and dispersion on the manageable influx volumes in MPD. Additionally, the IME design process includes provision for advanced alternatives for safe handling and removal of influxes within the limits of the primary barriers and those of the surface equipment.