Expanded IME with New Riser Gas Handling Operation Region

Abstract

The Influx Management Envelope (IME) is a proven tool to assess management of influxes taken during MPD operations. Currently, IME establishes limits of manageable influx volumes for given kick intensity/surface back-pressures, to hand over from primary to secondary barrier (i.e., well-control equipment). Opportunities exist for advanced, safe operations when influx circulation up the riser is a concern but dealing with the influx in the hole may introduce additional risks, such as imposing choke line friction pressures (CLFP), particularly in ultra-deepwater operations. A closed riser system allows for safe handling of influxes using the riser/MPD equipment, while isolating the wellbore with the subsea BOP and eliminating risks of fracturing the well or taking additional influxes. We propose expanding the current regions of the IME with a zone in which the decision can be made to circulate the influx to the riser, then isolate the well to handle the influx in the riser with MPD equipment, using the opportunities and methods being developed for industry use. Potential risks to the integrity of the system are analyzed and assessed versus reasonable scenarios. This work is consistent with the current work on providing guidelines for influx management with MPD (IM Annex to API-RP92S, under balloting process by API), and for managing gas in riser with closed riser systems (Riser Gas Handling (RGH) Guidelines, by the IADC UBO&MPD Committee).