Throughout the downturn in oil and gas prices, Master Flo Valve Inc. has continued investing in research and development, with a focus on helping customers lower cost and increase production. One of the results of this ongoing innovation is Master Flo’s new SL3 High-Resolution Subsea Actuator, which leverages installed subsea architecture to enable operators to incrementally increase production.
“We partner with our customers to understand what they’re facing in the field,” explains Dan Williams, Engineering Manager - Subsea Products at Master Flo. “This ensures that we’re providing solutions to their real-world technical challenges and business objectives. The SL3 High-Resolution Subsea Actuator is a perfect example.”
Development of the SL3 came about through collaboration with a customer that initially specified an electric actuator on a Master Flo subsea choke. However, the electric actuator was unable to provide the precise control required for the application. Because it couldn’t take position feedback directly from the choke, the actuator was unable to adequately control the position of the choke due to mechanical backlash in the ROV interface.
Master Flo based the SL3 on its hydraulic stepping actuator designs that have been proven in subsea applications for over 20 years. As a result, the SL3 delivers the customer’s required level of flow control—it has three times the number of opening set points of previous standard-resolution actuators—and is backward compatible with existing subsea chokes. It also provides the reliability for which Master Flo products are known.
“Reliability is crucial in subsea, whether on new wells or existing wells,” explains Williams. “By basing the SL3 on proven subsea actuator design, we were able to combine innovation with reliability to overcome challenges that many subsea operators are facing, whether they’re dealing with a new well or an existing well.”
For new wells, the SL3’s increased resolution makes it possible to bring production online with precision flow management that reduces the downhole pressure drop and surge experienced at each step. This decreases the likelihood of reservoir damage, sand production, and debris that can damage equipment. On existing wells, the SL3 enables production to be increased by opening subsea chokes in smaller increments right up to the sand breakthrough point without overstepping. Again, this decreases the chances of formation damage or excessive sand production.
In comparison, switching from a hydraulic actuator to an electric actuator typically requires prohibitively expensive modification of the installed subsea architecture, such as implementing battery power banks and additional power umbilicals. In older systems, sensors such as sand detectors on the subsea tree may have to be sacrificed due to the limited number of electrical connector slots on the subsea control module (SCM). Instead, the SL3 fits directly into the electro-hydraulic distribution control system already in place.
For new production wells with high-control start-up requirements, the SL3 provides additional savings. The increased resolution allows custom multi-port choke nozzles to be replaced by Master Flo’s standard patented 4-port cage and external sleeve design for most applications while still meeting or exceeding the controllability currently provided by existing multi-port nozzle designs. The 4-port design is recognized in the industry as providing the best erosion management, is more debris tolerant than multi-port nozzles, and reduces the risk of clogging ports in heavy oil and high asphaltene production.
“Our long-term partnerships with our customers, combined with our expertise in subsea flow management, are what allow us to understand the challenges and develop solutions that deliver significant value,” says Williams. “The choke valve isn’t just one small component of an overall engineering project. It’s the single point of flow control for a well. We understand how important optimized flow is to the economics of any well, surface or subsea, new or brownfield.”