End user Chevron Offshore oil rig

Guiding the future of actuation technology

Valve World had the pleasure of sitting down with Subsea Controls Engineer, Hailing An, at Chevron’s downtown headquarters in Houston, Texas, USA, during OTC week (Offshore Technology Conference) in May.
 
Article by Sarah Bradley
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After receiving her Ph.D. in Mechanical Engineering from Purdue University in Indiana, Hailing was presented with the opportunity to join Chevron Corporation in June 2007. She began her journey with the company as part of the Energy Technology Company (ETC) segment of the business, which is the internal consulting organization for all the business units and projects within Chevron. Having recently marked a decade with Chevron, Hailing shares the different roles she has assumed over the years.

Hailing was part of the Subsea Power and Pumping team for two years, managing a Long-Distance Power and Communications program, where she led the qualification of a nextgeneration power and communications umbilical to support subsea production boosting systems. Following that, she moved to one of Chevron’s major capital projects, Jack & St. Malo (JSM) –Stage2, where she managed the delivery of the production control umbilicals. Beginning in 2016, she reunited with the ETC team in the multi-faceted role of a Controls Engineer. This also marked her return to the technology side of the business.

Gaining momentum

“I perform the electrical and hydraulic analysis for the subsea controls system and work on new technology development in the area of subsea controls. In addition to my technical responsibilities, I also help develop and expand the internal organizational capabilities in the broader subject matter area of subsea equipment condition monitoring, which allow equipment performance indicators generated either diagnostically or predictively and alarms issued for out of spec operating conditions,” she explains. 

“This initiative is gaining a lot of momentum in this cost environment to ensure the reliability and integrity of the subsea equipment and minimize the production downtime.” Hailing also interfaces with other disciplines - such as Pipelines and Drilling & Completions - to help solve their equipment, design and control issues. Hailing is accustomed to thinking one step ahead.

Anticipating future needs

The key, explains Hailing, is to understand the business unit’s needs and anticipate future requirements. “In terms of new technology application, we look at what will be needed ten or twenty years down the road; so there are a lot of uncertainties associated with that. To be able to work around those uncertainties and guide the suppliers to develop their new technology towards our future needs is a challenging and rewarding process,” she says.

In her role, Hailing is tasked with the unique challenge of wearing two very different hats: that of project management, as well as the more technical role of performing analyses. She provides an example of her experience on the technology project management side: “Every year around OTC we get a lot of our suppliers, operators and partner friends coming to our office to present, discuss and get feedback on new technologies. I engage in these meetings to understand the newest developments, understand the applications, how they might bring value to our project needs.” On the analytics end, by contrast, Hailing is immersed in cross-data analytics ranging from routine system analysis which ensures the performance of the production control system delivered by suppliers is acceptable to creative data analytics which can bring in new insight to non-conventional equipment design, equipment performance condition, or the root cause of an operation issue.

Electrical and hydraulic analysis: subsea actuation

Hailing touches upon Chevron’s active involvement in all-electrical system development - a movement, she explains, towards supporting electrical systems that are able to replace hydraulic power. “Some of the drivers for this are that tiebacks are getting longer and longer and water depths are getting deeper and deeper,” she says. “When it comes to valves, our specific role on the ETC Subsea Controls Team involves subsea controls,” explains Hailing. Working with valves from the actuation perspective, for instance, Hailing must simulate and verify that the right actuators are used to properly open and close the valves being used on Chevron projects.

This involves transferring the properly specified hydraulic and electrical power through the flexible umbilical paths to control the subsea valves. To describe the scale of this type of operation, one must consider the number of subsea valves in operation at any one time. She explains, “On a subsea productions or injection tree you would have five or seven inch bore valves for production process control and smaller valves for annulus access and management and for chemical injections. On a typical tree, there will be 12 to 14 actuated valves, and you can have four to six trees per manifold in a drill center.” The result is anywhere from 48 to 84 valves which must be controlled with precision and accuracy.
ROVs inspecting subsea oil and gas equipment steel cage protection structure. Fictitious protection structure, oil and gas equipment.
ROVs inspecting subsea oil and gas equipment steel cage protection structure. Fictitious protection structure, oil and gas equipment.

Higher standard of accuracy

Performing the hydraulic analysis, Hailing is responsible for the analysis that assists in providing hydraulic power from topside through the umbilical tubes to open and close the valves on the subsea trees and manifold. She remarks, “What is required to perform these analyses is reliable actuator data from the suppliers.” While this level of accuracy may not be necessary in the design stage of product development, she explains, this data becomes much more important at later stages.

She adds, “We are developing our technology one step further and we are benchmarking our analysis with field data measurements. This requires a higher standard of accuracy in the input data. We found that the suppliers - who generally do not test their equipment in actual in-situ environments - are unable to provide the same accuracy that our analyses would require. In turn, we have to come up with ways to back calculate and correct them.” At Chevron, the input used in field verification analysis must represent empirical field measurements, as opposed to the lab testing conditions.

Challenges in offshore actuation: access to the valve

Hailing points to the unique challenges associated with controlling valve actuation in offshore environments. She remarks, “Onshore valve actuation is much simpler because several actuation options can be used to operate a valve. Plus, it is easier to access the valve.” In subsea applications, she explains, one cannot readily access the valve. Remotely operated vehicles (ROVs) can be used to perform various offshore operations. However, this method is much slower and more costly; it would be impractical to rely on this kind of procedure every time. As a result, most of the valves that open and close the most frequently are automated by hydraulic controls, and increasingly, by electrical controlled actuators. 

Another important consideration in subsea applications is material selection. Hailing explains, “For subsea, we certainly want to prevent corrosion and erosion. We have industry and company standards in terms of what kind of materials need to be used in subsea that are different from onshore applications.”

Industry trends

There are a number of upcoming technological developments on the horizon, affecting various aspects of O&G production, according to Hailing. One of these developments is the movement towards electrical actuation, which stands to positively influence umbilical design for increased optimization. Hailing asserts, “As mentioned, electrical actuators, All electrical Christmas trees are all emerging. There is a potential to move towards replacing all the hydraulic systems so that the tubes in the umbilical for hydraulic power transmission are no longer needed. Therefore, the umbilical crosssection size can be reduced and umbilical installation schedule can be improved. All Electric System has many other positive impacts on system CAPEX, Reliability, and Operability.”

Higher pressures

Another trend that stands to impact valve manufacturers is the need to develop equipment that is capable of withstanding higher pressures. Hailing explains, “So, you may have heard about the ‘20 kpsi’ projects. The pressure ratings for equipment is commonly qualified to 10K psi and 15K psi. We are going to deeper water and there are higher pressures and high temperatures involved. The industry now is developing 20 kpsi equipment for high pressure high temperature (HPHT) wells.”

When asked about the future of subsea, Hailing asserts jokingly, “That’s a question above me, but I can give my two cents. Chevron has a very strong subsea portfolio which is an area we keep working on. We invest in keeping a large number of subsea engineers in the company to provide the expert support to various subsea projects.” It stands to reason that Chevron will continue to be on the leading edge of subsea technological developments tomorrow and for years to come.

Quick facts

An umbilical is defined as “A group of functional components, such as electric cables, optical fiber cables, hoses, and tubes, laid up or bundled together or in combination with each other, that generally provides hydraulics, fluid injection, power, and/or communication services.” Subsea umbilicals are deployed on the seabed (ocean floor) to provide the necessary control and chemical services to operate subsea oil and gas wells and associated infrastructure. Similarly, umbilicals are used to provide necessary services for subsea intervention, including remotely operated vehicles and offshore drilling or workover activities.

About Hailing An

Hailing An: “In terms of new technology application, we look at what will be needed to efficiently develop a subsea asset ten or twenty years down the road. To be able to work around those uncertainties and guide the suppliers to develop their new technology towards our future needs is a challenging and rewarding process.”

Chevron

Headquartered in San Ramon, California, USA, Chevron is a multinational energy corporation with operations in more than 180 countries. One of the largest oil companies in the world, the company is engaged in every aspect of the oil & gas industry, from exploration, production and refining, to transport, marketing and power generation. The company is also involved in alternative energy initiatives, which include geothermal, solar, wind, biofuel, fuel cells and hydrogen power.
 

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