16th US-Norway Technology Partnership Conference 2014 EC-Drill MPD Dual Gradient Drilling John A. Cohen, R&D Technology Manager AGR Enhanced Drilling February 26, 2014 Houston, Texas Enhanced Drilling
Content The Challenge MPD and DGD The EC-Drill Technology Case Studies EC-Drill on Scarabeo 9 (Cuba) EC-Drill on COSL Innovator (Troll NCS)
The Operators Challenge
Low Mud Weight Environments Major challenge is losses to the formation EC-Drill benefits Drill rate limited by ECD margin drill faster with EC-Drill system Horizontal length limited by ECD margin drill further with EC-Drill System Applicable to ultra-deepwater areas with shallow reservoir targets including offshore areas such as: GOM (Perdido area) Brazil Egypt (Mediterranean) Nigeria (>6,000 WD)
High Mud Weight Environments Major challenge is narrow drilling window EC-Drill benefits Eliminate dynamic ECD Drill with constant BHP Applicable to ultra-deepwater areas such as: GOM Brazil West Coast Africa Australia & New Zeeland
MPD / DGD Technologies
IADC Defined MPD / DGD Technologies
The EC-Drill Technology
EC-Drill Technology EC-Drill is a Controlled Annular Mud Level technique for post BOP hole section drilled from Floating Drilling Units while controlling BHP, Pressure Gradient & ECD EC-Drill is used within boundaries of conventional Well Control
EC-Drill MPD / DGD Technology A step-change technology that enables operators to drill the undrillable well Enables operators to negotiate Narrow Pressure Windows in deepwater by controlling bottom hole pressure Enhances safety Saving cost Used on three deep-water wells to date
EC-Drill MPD / DGD Technology An open to atmosphere system (No RCD) A riser joint is modified with an outlet and valves and connected to a subsea pump, which h pump the drilling fluid back to the MODU The subsea pump p can be riser mounted or run independently The riser is equipped with pressure sensors to measure the exact riser fluid level, and allow for real-time BHP calculations The drilling fluid level is controlled and adjusted to provide desired annular pressure profiles, i.e. the gradient Bar/Psi BHP is automatically controlled and adjusted in real-time by the control system
Narrow Margins RKB Conventional Static Hydrostatic Mud Pressure Gradient Conventional Dynamic Hydrostatic Mud Pressure Gradient Seabed Depth Last Casing Shoe Seawater Hydrostatic Pressure, psi
EC-Drill Track Record No Year Company Country Rig Type Water Depth (meter) 1 2008 BP Egypt Jack-up 19 2 2010 BP Azerbaijan Jack-up 101 3 2011 Petrobras Brazil Jack-up 30 4 2011 Petrobras Brazil Jack-up 30 5 2012 Repsol Cuba Semi 1780 6 2012 Petronas Cuba Semi 2286 7 2012 Petrobras Brazil Jack-up 20 8 2012 PDVSA Cuba Semi 2193 9 2013 Petrobras Brazil Jack-up 70 10 2013 BP Azerbaijan Jack-up 101 Note: Jack-up wells are "top-hole" / pre-bop, but where the fluid level inside the conductor pipe has been manipulated to control BHP.
EC-Drill Attributes No water depth limitations Applicable to both low and high mud weight environment Use conventional LP Drilling riser and subsea BOP Drill with overbalanced mud weight Used to control BHP during Cementing
EC-Drill Attributes (con t) Lower fluid level in drilling riser to reduce ECD Increase flow rate, hole cleaning and ROP Drill with near constant BHP Active volumes are monitored Flow variance is monitored
Scarabeo 9: EC-Drill Cuba Project
EC-Drill on Scarabeo 9 (Cuba) Water depth 1800-2200 m Pump depth 400 m ECD reduction Mud weight used Max mud flow rate up to 40 bar 1.1 1.4 sg 6000 lpm 3 wells drilled in 1800 2200m water depth 22
Background Exploration campaign in ultra-deepwater GoM Previous attempt failed to reach well objective Inability to maintain circulation while drilling in reservoir No RCD-based MPD was applicable Low mud weight requirement Chalk and limestone formation Potential for weak zones -- risk of severe losses Improved ROP Reduced riser level Increased circulation rate
C1 Well Specific Objectives / KPI's No losses achieved Stable well achieved Improved hole cleaning - achieved Increased ROP - achieved No gas in top of riser achieved. No NPT recorded Increased ROP demonstrated
COSL Innovator: EC-Drill Troll Pilot Project
Troll Dual Gradinet Pilot Typically 3 x 3 km laterals in reservoir for each well Business Case: - Depleted reservoir Short term business case: Losses, bad cement jobs Long term business case: Cannot drill conventionally with water based mud after 2018
References IADC/SPE-164561-MS Successful Application of Deep Water Dual Gradient Drilling R Ziegler, Paul Ashley, M S A Sabri and M R B Idris, PETRONAS; R Malt, R Stave, K R Toftevåg, AGR Enhanced Drilling SPE 151100-MS- First Application of EC-Drill in Ultra- Deepwater, Proven Subsea Managed Pressure Drilling Method R Ziegler, PETRONAS; M Mir Rajabi, K Toftevåg and R Stave, AGR Enhanced Drilling SPE 130308-MS Deepwater Riserless Mud Return System for Dual Gradient Tophole Drilling W Winters, BP; B Tarr and R Ziegler, Shell; I Riza, M Faisal, PETRONAS; D Smith, AGR Enhanced Drilling Why we do it John-Morten Godhavn - Statoil, IADC Dual Gradient Drilling Seminar, Milan, March 19th 2012
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