Michael Padilla - INTECSEA
This article addresses the progress made through the application of subsea processing, separation, and boosting technologies in the past year. Maintaining the momentum from a number of recent/current subsea processing installations, development programs and project applications continue to provide the industry with new technical advancements and opportunities, and some challenges, too.
Operators continue to initiate and to fund studies into boosting, separation, compression, and power delivery and distribution when developing new fields. In an attempt to capture the full value of subsea processing’s technical and economic advantages, operators are taking the lead in field development. An increase in overall confidence towards subsea processing packages is the result of ongoing development and the success of current systems. Operators appear more open to investigation and development of project-specific equipment, and now ask more questions about economics and application details rather than voicing previous concerns about risk and reliability.
INTECSEA has completed multiple proprietary Gulf of Mexico projects which carried subsea processing solutions through the conceptual and pre-FEED stages. Each project performed detailed studies into the current industry offerings; identifying current hardware while also planning the development of future complementary technologies required for the entire system. For example, identifying the optimal type and size of a subsea pump for an application is only half the battle. If the necessary wet-mate electrical connectors and penetrators are not available, the pumps have to wait.
As the primary subsea processing disciplines (separation, boosting, and gas compression) are applied to projects, evolution of the drivers for each of the disciplines continues. Stated advantages are being complemented with new drivers as necessity breeds development. This is evident in the BP King and StatoilHydro Tordis projects, as both have dealt with unplanned interruptions during the first few months of operation. Yet these interruptions are viewed as progress towards more efficient solutions; a necessary step in the evolution of the technology. During the Subsea Boosting and Processing Joint Industry Project conducted by INTECSEA in 2007, operators voiced the realization that unforeseen problems were more likely in the first two years than the following three to five years. That is, problems are identified and solved in the early part of application life so operations are much more trouble free after that. The same concept applies to technologies in general. As problems are identified and solved, future applications should be much more reliable.
Subsea boosting continues to pave the way for the other subsea processing disciplines in its development and experience. While Framo continues to develop its Hybrid and High Boost pump technology to combine the benefits of helicon-axial and centrifugal pumps for Pazflor, the Camforce joint venture of Cameron, Curtiss-Wright, and Leistritz anticipates results from the pending Marlim twin-screw pump installation. Keeping pace, Aker Solutions continues to develop its new semi-axial pump technology to rival the Framo offerings, while Bornemann and Flowserve continue to advance the technology of twin screw designs, including Flowserve’s future target offering of a 5-MW pump system.
Schlumberger and Baker Hughes Centrilift continue to develop electrical submersible pump (ESP) technology. Centrilift expects successful installations offshore Brazil will continue to push the advancement of ESPs. Pending installations and operations include BC-10, Golfinho, and Albacore Leste. Similarly, the Shell Perdido project aims to set the stage in the Gulf of Mexico by using ESP technology in 8,000 ft (2,438 m) of water with five boosting packages.
Looking further into the future, gas developments at Aasgard and Ormen Lange (both slated for 2012) still are on pace to establish new baselines in gas compression and power distribution technology. A project update for Ormen Lange is expected at the 2009 Subsea Tieback Forum in San Antonio, Texas.
Effects that the current economic downturn will have on the industry cannot be quantified, but it has not yet prevented operators from investigating, developing, or committing to continued development of subsea processing technology.
To continue this conversation, contact INTECSEA by e-mailing[email protected].
Reasons for subsea compression, boosting, water injection, separation
COMPRESSION
Increase subsea tieback distance
Improve flow assurance issues
Eliminate offshore platform(s)
ENABLER: The field could not be developed economically and/or technically (i.e. - Gas tieback under ice in Artic regions)
BOOSTING
Reservoir advantages
- Increase ultimate recovery by lowering abandonment pressure
- Enable oil recovery from low-pressure reservoirs
- Enable oil recovery of low-quality fluids
Production advantages
- Increase production rate by reducing flowing wellhead pressure
- Reduce opex by reducing recovery time (shorten life of field)
- Offset high-friction pressure losses in flowline due to fluid viscosity
- Offset elevation head pressure loss
Facilities advangages
- Longer subsea tiebacks
WATER INJECTION
Eliminate topsides water injection equipment
Eliminate water injection flowlines
SEPARATION
Minimize topsides water handling
Hydrate control by removing liquids from gas stream
Increase hydrocarbon production volume
Decrease total boost system power requirements
Accelerate and/or increase recovery
Improve flow management, flow assurance
Reduce capex on topsides processing equipment and pipelines
Improve economics of field with low GOR, high viscosity, low permeability
COURTESY OF INTECSEA AND BHP BILLITON
