When companies look to reduce costs offshore, one of the areas of interest is topsides processing, where improved efficiency often delivers greater safety along with better processes.

Certainly, this is the case for an improved process for removing mercury from condensate, which was the subject of a presentation by Imane Aguedach of Alfa Laval Lund AB in the “Topside Innovative Processing and Design” session on April 30.

Aguedach suggested mercury removal could best be achieved using a high-speed hot spin centrifuge that allows continuous operation without impacting production. She explained several advantages of this technology, including its small footprint, hermitic sealing that protects workers and the environment, and the ability to clean the equipment in place.

Another technology, which was developed by GE Power & Water for use by Petrobras offshore Brazil, focuses on reducing the amount of water used in offshore chemical cleaning in sulfate removal units (SRUs).

According to Gustavo Garios Lage, Petrobras, freshwater has become a scarce resource on some offshore assets. Instead of purchasing freshwater, which can be costly and logistically challenging, Petrobras is using the GE solution of using purified water. This permeate feed solution has low sulfate content and is used for injections and cleaning in place. In trials offshore, Lage said, Petrobras achieved the same results as were delivered with freshwater systems, using less water and fewer manhours while reducing downtime.

Another advancement was presented by Chien-Chiang Chen, ExxonMobil Upstream Research Co., who shared novel adsorption-based gas treating technology platform for use in upstream gas separation, a process similar to the conventional process but which happens more quickly. According to Chen, the new approach achieves in a 250-second cycle time what traditional systems can only deliver in a matter of multiple days.

“What is exciting about this concept,” Chen said, is that it is a “platform technology,” which has much broader scope for application such as removing chemicals.

The current focus is deep dehydration and low-level CO2 removal for cryogenic applications. Key enabling mechanical systems have been developed, and pilot studies have confirmed technical feasibility for deep dehydration.

Tom Latta, WorleyParsons Canada/Advisian, talked about his company’s work on evaluating design considerations to minimize hydrocarbon entrainment. Latta explained the need to determine what valves are driving design, noting that the type of valve is important, but that estimating drop size distribution is critical for trying to get a “realistic” idea of what is going into the system. He presented his company’s work on developing a way to mathematically determine the distribution to improve understanding of what is happening in the system.

While some companies are looking at improvements on a systems level, others are improving components. David Leavitt, Emerson Automation Solutions, told attendees about a triple offset valve that can replace rising stem ball valves in natural gas molecular sieve applications that contends with the challenges of high-cycle frequency, thermal cycling, abrasive particles and corrosion where there is sour gas in the hydrocarbon stream.

According to Leavitt, this valve delivers quarter turn operation with metal-to-metal, torque seated, cone-in-cone seating, in a maintenance-free design that has proven to provide zero leakage.

Kenneth Rosen, ENI Norge AS, presented a new method for process isolation that was developed by Kjetil Aamodt at IK Norway AS. The special pipe clamp is used for sealing lines on pressurized lines.

The main benefits of the design, which Rosen said is the first in the world of this design, is that it enables shorter shutdowns and improved uptime and conforms to recognized standards. It is field-proven and is available in two versions (one for process segregation and the other to isolate and disconnect).

Offshore