T E C H N O L O G Y F O C U S

Locked In:Offshore Isolations

Companies that create technology are always working on the next big idea.

Often, innovation originates from breakthrough, whiz-bang, lightning-strikes thinking.

But sometimes, instead of a revolution, an evolution will do just fine.And sometimes, that evolution begins with a little prompting from

the marketplace.Such is the case with the hydraulic locking capabilities of the

tetherless, remote-controlled SmartPlug® isolation system. Evolving versions of this non-invasive plugging technology have been isolating offshore pipelines for more than 20 years. SmartPlug tools, designed by pipeline service provider T.D. Williamson (TDW), remotely isolate and stop product flow to a designated area of the pipeline so that maintenance, repair or tie-ins can be performed in a safe, inert environment.

A key component of the system is its ability to hydraulically lock into place during isolation in a lower pressure line. This locking mechanism supplements, or can even replace, pipeline pressure differential to more securely hold the isolation tool in place.

Without hydraulic lock capabilities, and in the case of a substantial drop in pipeline pressure, the differential pressure across the plug could diminish to a point that the tool could naturally begin unsetting. This would cause both the pipeline operator and service provider to take immediate corrective action, resulting in delays and wasted time and money, potentially jeopardizing the whole operation. But hydraulic locking capabilities provide an additional level of safety and security, allowing the tool to maintain the isolation regardless of pressure changes within the pipeline.

“Hydraulic lock capability greatly increases safety during pipeline isolation,” Gary Anderson, Director of SmartPlug Technology, explains.

“By continuing to expand the locking function across all sizes of the tool, operators will ultimately benefit from the same safeguards and risk mitigation, regardless of the diameter of their line.”

Hydraulic Locking a NecessitySmartPlug tools come in a variety of sizes – for every pipeline diameter from 8 inches to 48 inches, there’s a unique, specific isolation tool with a proprietary intelligent control system to match. Offshore operators who had experience using the SmartPlug tool in larger diameter pipelines

asked TDW to add hydraulics to the control system for use in their smaller diameter lines. According to Anderson, not only do operators see the technology as desirable, some believe it’s a necessity.

Anderson cites an example of an operator working in the Gulf of Mexico who sees hydraulic locking capabilities as a requisite part of its plugging operation.

“For this operator, the hydraulic locking capability is a ‘must-have’ safety feature,” Anderson says. “The client needs to isolate a smaller diameter pipeline, but the previous control system for this particular size of SmartPlug tool didn’t yet have the ability to hydraulically lock the tool in place.”

This need expedited the introduction of the next generation of control module that will bring the tool within the client’s operating guidelines and provide the requisite level of safety and redundancy.

All SmartPlug control systems are operated topside by laptop computer. The system uses extremely low frequency technology to enable communication so the operator can send commands and receive real-time, two-way, through-wall data about plug, pipeline and other key conditions.

The newest control module continues to expand

the locking options for operators of smaller diameter lines. But, regardless of diameter, operators continue to rely on the DNV-certified, double block safety of the SmartPlug® isolation system.

Risk is defined by Det Norske Veritas (DNV) as, “the

qualitative or quantitative likelihood of an accidental or

unplanned event occurring, considered in conjunction with

the potential consequences of such a failure. In quantitative

terms, risk is the quantified probability of a defined failure

mode times its quantified consequence.”

The SmartPlug isolation system provides operators with

options for self-locking technology in high pressure lines

and hydraulic locking for use in low pressure. Both choices

provide a double-block method to greatly reduce risk, as

every SmartPlug tool receives a Type Approval Certificate from

DNV, confirming compliance with DNV-OS-F101 standards.

Certification includes a detailed Failure Mode, Effects, and

Criticality Analysis study based on a Fault Tree Analysis.

Doubling Risk Reduction

SmartPlug® isolation technology featuring hydraulic locking in low pressure lines