HOUSTON – Halliburton (NYSE:HAL) has introduced a package of low equivalent circulating density (ECD) technologies at the Offshore Technology Conference. The approach combines new and existing technologies to help reach and produce reservoirs with low ECD margins, particularly in deepwater offshore wells.
New technologies in the oil-based drilling fluids system package include the VersaFlex Low ECD System, the Commander 1000 Top-Drive Cementing Head, and a high-pressure shearing unit. The drilling fluids reduce fluid loss to help keep the hole clean and reduce problems with barite “sag” while using the same basic drilling mud handling hardware. An added mud conditioning tool means the drilling fluid reached the location in a ready-to-run state and does not require circulation for final conditioning.
VersaFlex reduces pressure drop across the liner-top during circulation and cementing for easier ECD management. The ECD running tool works in conjunction with the VersaFlex Low ECD expandable liner hanger (ELH) body.
The Commander 1000 top-drive cementing head is designed to surface launch balls or darts in order to operate subsea plug sets. This top-drive or rotary-rig cement head can be manually actuated to release the operating darts or balls by way of the ball-drop port. The advantages are that it can load plugs offshore without breaking the tool apart to install the plugs and that it can drop the plugs while flowing. This dynamic launch feature helps keep the fluid flow rate consistent for better ECD management and reduced surges and swab.
Other parts of the system include the SuperFill Surge Reduction Equipment, Protech CRB Centralizer, iCem service, and Drilling Fluids Graphics fluid prediction and modeling.
“Wellbore integrity issues, including lost circulation, can account for a significant amount of nonproductive time,” said Chip Miller, vice president of Halliburton’s Baroid business line in introducing the system. “As operators drill more complex wellbores in difficult reservoirs, this Low ECD Solution uses an integrated-technology approach to address our customers’ ECD issues, increase efficiency, and maximize recovery.”
ECD occurs when friction in the well from circulating drilling mud and fluids during cementing operations results in increased bottomhole pressure, which can cause challenges in well integrity and safety. Halliburton’s Low ECD Solution is designed to:
- Maintain hydrostatic pressure of the fluid column below the fracture gradient but above the pore pressure, while maintaining well control
- Reduce overall fluid viscosity to reduce frictional forces
- Allow drilling fluids, spacer and cement to flow freely into the casing and up the annulus to avoid lost circulation, while still providing hole cleaning
- Minimize surge in the formation while running the liner so pressure drop across the hanger is reduced
- Increase the bypass circulation rate while not exceeding the fracture gradient of the formation due to pressure build-up.