Bridging the gap between MPD and Well Control

Abstract

Abstract The increasing use of Managed Pressure Drilling (MPD) has been proven to enhance drilling operations in conventional, narrow margin, High Pressure-High Temperature (HPHT) and, in particular, deepwater operations. Its success does not come easily, as the technique challenges the conventional drilling paradigm along with drilling contractors’ and operators’ policies and standards. Conventional drilling practices for connections, flow checks, tripping, and well control have been long understood and standardized both onshore and offshore. The addition of an MPD system to a drilling operation, inclusive of the recommended practices, makes necessary bridging the gap between conventional policies and standards and those of MPD. This bridging document will produce a formal standard, specific to each project and/or operation. When a new drilling campaign is initiated, the operator typically begins designing a well plan and high-level drilling program by referencing their current standards and policies. Once a drilling contractor is selected, the challenge of bridging the drilling contractor’s policies with the operator’s standards begins. If the drilling campaign is to include MPD wells, the inclusion of MPD then adds an additional layer of complexity to the established bridging document by challenging standard operating procedures and forcing operators and contractors to create step-outs from their policies. It is often seen as an operational requirement that a MPD bridging document supplements the standard drilling contractor’s and operator’s bridging document, standing apart from the already established policies. Instead, MPD should be viewed as a way to enhance the currently acceptable policies and practices and should form an integral part of a combined operational policy document. MPD challenges conventional drilling practices, and both MPD and drilling personnel must work closely together during operations. However, regarding well control, the drilling contractor remains ultimately responsible. The driller will continue to monitor the well using standard drilling contractor operating procedures, and observe key drilling parameters with enhanced MPD indicators. The MPD system provides enhanced well control event detection in addition to standard conventional down hole and surface event detection methods while also allowing rapid and accurate control of bottom hole pressure (BHP). This does not replace the drilling contractor’s or operator’s well control polices. Further examples of how MPD impacts conventional operations include: What is considered an adequate flow check in both duration and monitoring?What additions are there to the primary barrier envelope?What volume and intensities of influxes can be safely managed through the Riser Gas Handling (RGH) system and/or MPD system, maintaining the primary well control barrier? Without formalizing a bridging document between the drilling contractor’s, operator’s, and MPD service provider’s policies to address issues like these, gaps will remain, thereby exposing the operation to the risk of failure and mitigating the potential gain that can be realized from utilizing MPD. The intent of this paper is to highlight the specific areas where conventional policies are challenged by MPD operations and to attempt to offer guidance when implementing and managing this technology. It is also to be used as a tool to raise awareness to ensure that operations are carried out in a safe and efficient manner according to the agreed upon policies, procedures, and standards currently in place, as well as to minimize the potential risk to personnel, environment, and equipment.