Developing a methodology for generating an influx management envelope in MPD operations.

Abstract

In addition to enhancing drilling efficiency and safety, Managed Pressure Drilling (MPD) offers the potential for vast improvements in the influx handling process. Some of today's MPD technologies are designed to detect and terminate influxes dynamically by applying surface backpressure (SBP) without circulation interruption. This rapid response during influx events results in significantly smaller influx volumes when compared to conventional shut-in and weight-up. Furthermore, avoiding shut-in scenarios while regaining the overbalance retains the ability to circulate these trapped small influxes through primary barriers of the MPD system. The Influx Management Envelope (IME) is an enhanced, innovative decision-making tool, which defines the acceptable limits for safe circulation of the influx out of the wellbore using only the MPD system (primary barriers) without the need to shut in the well. Influxes that exceed the safe circulation limit of the envelope must be circulated out using a secondary barrier (i.e. conventional well control operations). The appropriate utilization of IME in the MPD technology eliminates many of the potential hazards of conventional well control applications, achieves faster removal of the influx from the wellbore, and hence reduces Non Productive Time (NPT). A comprehensive methodology for generating a more realistic IME was developed in this thesis based on executing a series of dynamic well control simulations. Additionally, the shape of the IME that constructed based on this methodology was advanced by adding other elements to the envelope. This methodology increases the operational window of the IME and allows safely circulating larger influxes through the MPD system without exceeding the pressure and flow limits of the system