As subsea oil and gas fields push into deeper waters and more complex installations, ensuring the integrity of umbilicals during pre-commissioning has become crucial. EnerMech’s subsea testing innovations are meeting these challenges head-on. Here, we explains how our dual-approach solutions provide flexibility and reliability in some of the harshest offshore environments.
Expanding subsea oil and gas fields into deeper waters brings significant technical challenges, especially when integrating new infrastructure with existing systems. The pre-commissioning of subsea umbilicals, key components responsible for delivering hydraulic fluids, chemicals, power, and communications, is particularly complex at depths often exceeding 1,000 meters. We have developed two advanced techniques for subsea umbilical pre-commissioning that address the demanding conditions encountered in deepwater expansions. These solutions enable operators to confidently integrate new wells, flowlines, and umbilicals into existing infrastructure, even at depths exceeding 1,000 meters.
One of the key technologies powering these advancements is the Umbilical Subsea Test Pump (USTP) system, which is a self-contained, ROV-powered unit. Equipped with twin pumps and fluid reservoirs, it is capable of handling both hydraulic fluids and MEG (mono-ethylene glycol) or chemical blends critical for subsea operations. It is deployed to the seabed and controlled remotely via the ROV’s hydraulic power and an optical uplink system, allowing real-time pressure monitoring and data collection. This configuration enables operators to carry out precise pressure testing and leak verification on shorter umbilicals or flying leads where fluid volume is limited. The system’s onboard filtration and flushing capabilities meet stringent cleanliness standards, ensuring the integrity of critical hydraulic lines during testing.
In contrast, for larger umbilicals or situations requiring greater volumes of testing fluid, EnerMech utilizes twin single-section composite downlines. These composite lines are self-supporting, collapse-resistant, and designed to handle pressures up to 10,000 psi. The twin downlines are deployed from the surface, delivering hydraulic and MEG-based fluids directly to the subsea umbilical ends. Their smooth-bore design maintains fluid cleanliness and structural integrity throughout the operation. With lengths typically around 1,500 meters, the downlines allow for extended testing capabilities without the volume restrictions inherent in ROV-powered systems.
Subsea umbilicals play a crucial role in transporting hydraulic fluids, electrical power, and communication signals from surface facilities to subsea equipment. During brownfield expansions, where new infrastructure ties into existing subsea networks, both ends of the umbilical are terminated subsea, which makes surface-based testing impossible. EnerMech’s dual testing approaches ensure integrity and safety by addressing the logistical and technical challenges posed by deepwater environments, ranging from 900 to 2,200 meters in depth.
The choice between the USTP and composite downline methods depends on project-specific factors such as fluid volume requirements, umbilical length, and operational preferences. The USTP system offers mobility and ease of deployment, ideal for smaller scale or complex flying lead configurations. Meanwhile, the composite downlines cater to larger scale operations requiring significant fluid volumes and extended testing durations.
EnerMech’s solutions are the result of a pragmatic and client-focused approach, adapting existing pipeline pressure testing technologies to develop subsea umbilical testing systems quickly and effectively. By investing in equipment such as composite downlines and refining operational protocols, EnerMech has positioned itself as a leader in the subsea testing niche, delivering reliable, repeatable, and high-integrity testing services globally.
As oil and gas exploration pushes into deeper and more challenging waters, the need for innovative subsea umbilical pre-commissioning techniques will only grow. EnerMech’s twin-method approach ensures operators can maintain the highest standards of safety and reliability for both new field developments and brownfield expansions, enabling the industry to meet future demands with confidence.