Developing an Influx-Management Envelope for a Deepwater MPD Operation

Abstract

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 185289, “Case Study: First Experience of Developing an Influx-Management Envelope for a Deepwater MPD Operation,” by O.R. Gabaldon, P.R. Brand, M.S. Culen, I.U. Haq, R.A. Gonzalez-Luis, T. Pinheiro Da Silva, G. Puerto, and W. Bacon, Blade Energy Partners, prepared for the 2017 SPE/IADC Managed Pressure Drilling and Underbalanced Operations Conference and Exhibition, Rio de Janeiro, 28–29 March. The paper has not been peer reviewed. The influx-management-envelope (IME) concept is an advanced, innovative way to assess influx conditions in managed-pressure-drilling (MPD) operations, offering an improved tool for the decision-making process. The complete paper presents the process of developing the IME concept for a deepwater MPD operation for the first time. The IME Concept The IME concept defines the operational envelope in case of incidental influxes during MPD operations. It is based on kick-tolerance concepts, in which a relationship between volume and intensity of the influx is established and plotted as a graph. A resulting combination of regions within the volume-and-intensity graph depicts the conditions in which an influx can be removed safely from the wellbore by use of the elements of the primary wellbore barrier; otherwise, the secondary wellbore barrier should be engaged and the well shut in conventionally. The regions are color coded for ease of identification during the process of managing an influx. Three regions have been described: The Green region identifies normal MPD operations, where drilling and other operations continue as planned. No influx is detected in the wellbore, and surface pressures are within planned parameters. The Yellow region defines the operational region where an influx has been detected in the wellbore and the influx can be circulated safely to surface within the boundaries of the primary wellbore barrier. The Red region defines the conditions in which it is deemed that some limits of the primary barrier would be exceeded during the process, indicating that the well should be secured with a secondary-barrier envelope. The Orange Region. In this work, an additional (optional) Orange region is added as a subset of the Yellow region (Fig. 1). In the Orange region, an influx can be removed safely within the primary wellbore barrier but one or more parameters will need to be modified to avoid exceeding some limits in the process.