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COVER PARTNER
STENA DRILLING: A MANAGED PRESSURE DRILLING CONTRACTOR Reacting to a competitive Deepwater rig market as well as Operator’s increasing requests for Managed Pressure Drilling (MPD) capability in rig tenders, Stena Drilling identified a requirement to establish MPD Capability within its Deepwater fleet and in February 2016 sanctioned the purchase and integration of two Deepwater MPD systems on Deepwater Drillships. Since then the company has doubled its MPD fleet to four MPD Drillships and has successfully utilised all four systems to drill a total of eighteen Deepwater MPD exploration and appraisal wells across multiple regions and for multiple operators. This journey from ‘MPD Curious’ to providing a fully integrated MPD service as part of the rig contract has been the result of significant technical and operational achievements by Stena Drilling’s teams in close collaboration with the MPD Systems OEM, the vessels’ Classification Authority, and major Operators.
Stena Drilling MPD Crew on board the Stena IceMAX
MPD fleet are functionally identical, using the same control systems, hardware and layouts with a single OEM for support provides significant efficiencies in the management and continuous improvement of MPD operations as well as helping ensure crew competency and providing operational assurances. The closed loop, below tension ring MPD system incorporates some of the industry’s most advanced MPD technologies and has now been proven to deliver successful MPD wells consistently since 2017.
The Integrated Riser Joint is a single 40-foot assembly weighing just under 35 metric tonnes with a maximum outer diameter of 56 inch and minimum inner diameter of 18.77 inch. The joint consists of a 18-3/4” Stena Drilling’s Rotating Control Device housing; a 21-1/4” slimline annular and a flow spool with dual outlets on the bottom. An adaptor spool (top) integrated MPD service The MPD Service Model and integral flanged connection (bottom) allow quick and easy model provides the Operator make-up to the rigs riser system. The joint is deployed, below the Following dialogue with the industry it tension ring but above the termination joint for the riser auxiliary with a rig equipped with all became apparent that for Deepwater lines (choke, kill, boost, conduit etc.) meaning the IRJ itself has necessary systems required MPD operations, Operators increasingly no external auxiliary lines reducing its overall weight and aiding wanted to move from a rental MPD to perform all aspects of general handling as well as maintenance on all drill through Service with its higher mobilisation components. Two six-inch flowline hoses connect the IRJ via Deepwater MPD and integration costs towards a fully the flow spool to the surface distribution manifold with a two-inch integrated, Drilling Contractor ‘Owned and operations bleed line running from a port between the RCD and slimline annular Operated’ operational service offered as part to the distribution manifold. A control umbilical connects to the joint to of the wider rig service. This was also identified the surface control system via an umbilical reel. by Stena Drilling’s management as the preferred solution as, having had brief experience with rental MPD The surface system consists of a main distribution manifold connecting the MPD systems in 2014, it was clear that assuming ownership and system to wider rig systems including standpipe and choke manifolds, the shale responsibility for the MPD system was the only way to give shakers and Mud Gas Separator. Immediately downstream of the Distribution the Drilling Contractor the risk assurance it desired when Manifold is a Junk Catcher manifold featuring dual junk catchers intended to engaging in such a critical well activity. protect sensitive equipment downstream from plugging/damage. Downstream of the Junk Catcher, the MPD Choke Manifold consists of two parallel, six-inch Stena Drilling’s integrated MPD service model provides the Operator with a rig equipped with all necessary systems, competent personnel and detailed procedures required to perform all aspects of Deepwater MPD operations. The model provides a purpose-built system which conforms to the same design, installation and maintenance standards as the wider rig, in line with Classification, industry and regulatory rules. The system is maintained and operated by the Drilling Contractor’s crew using a combination of existing rig crew upskilled for MPD operations as well as new MPD positions, namely MPD Toolpushers and Control System Operators. These trained and competent crews deploy and operate the MPD system per Stena Drilling’s specific MPD operating procedures and in line with the Operator’s well program, ensuring a consistent approach with more assured outcomes.
System Description Consistency of design as well as a using single equipment supplier for the MPD system was identified by Stena Drilling as critical to the success of the wider service model. Ensuring all MPD systems across the company’s
www.ogv.energy I January 2022
MPD Controls and Manifolds on a DrillMAX class vessel
