A Combined System for Improving Well Planning and Execution from Spud to Completion

A dual-purpose system combining Riserless Mud Recovery (RMR) for pre-BOP operations with a Controlled Mud Level (CML) Managed Pressure Drilling (MPD) system for post-BOP operations is presented. The intent is to simplify the well design, improve the drilling execution and increase production. The combined system is a greener approach with zero discharge, and requires less cement, drilling fluid and steel to complete the well. Drilling topholes with returns allows for an engineered fluid, elimination of pilot holes, Managed Pressure Cementing, extending top hole sections and kicking off earlier; these are all options with RMR. The 2-in-1 system can be used for CML operations for the rest of the well without retrieval or re-deployment of equipment. CML creates a dual gradient effect by lowering the fluid level in the riser which causes the pressure profiles to better align with most operating windows, even negative windows. It also enables Managed Pressure Completion, which is particularly beneficial for Gravel Packing. RMR and CML have long individual records for riserless drilling applications and MPD, respectively. Case studies will document how RMR has been used to re-engineer the drilling approach and is beneficial for environmentally sensitive areas with zero discharge to the seabed. CML MPD is frequently used for purposes beyond a Constant Bottom Hole Pressure (CBHP) approach focusing on increased production and eliminating casings with the pressure profiles created by the dual gradient effect. During one campaign, the combined system was used to de-risk the drilling campaign actively throughout by setting the 20’’ Shoe deeper, ensuring critical TOC for the intermediate casing, controlling the bottomhole pressure while drilling through a depleted zone, and enabling a gravel pack completion. This system offers new approaches in planning and execution from spud to completion while simultaneously reducing the carbon footprint of the well, for both pre-BOP and post-BOP operations, by saving rig time, reducing well control events, and simplifying fluid logistics.