Decades of experience in the oil and gas industry. Involvement in all aspects of product development, including subsea oil and gas projects. 

Deepwater pipeline repairs were originally designed around vertical connections. These included vertical jumper spools that posed inherent risks as large sections extended upwards in an unprotected condition. A horizontal repair system was developed for our customer and included connectors for a range of pipeline sizes. The system included a complex connecting structure that permitted installation of the horizontal repair section without significantly disturbing the pipeline under repair. The system was designed, built and successfully subjected to systems integration testing

This standard connector is designed to protect subsea pipelines by separating when subject to high external tension loads while being insensitive to the thrust load induced by internal pressure. The pressure equilibrium system was disturbed by high external pressures in deepwater. In order to fulfill customer requirements, a pressure compensated system was incorporated into the design to maintain the functionality in deepwater. In addition, a hyperbaric chamber capable of imparting tension loads was designed and used to test the connector to demonstrate full functionality.

Whereas elastomer sealing connectors for pipelines were once perceived to be limited from low to moderate pipeline pressures, two different sizes of connectors (16” and 18”) were designed and tested to pressures exceeding 11,000 psi.

These ball fittings allow for misalignment between connecting ends of two pipelines and ultimately are secured on a metal sealing surface. Design solutions become challenging for sizes over 30” due to diminishing stiffness. Connectors for a 56” Middle East pipeline were designed, built and successfully subjected to functional & pressure testing.

Pipeline Pigging wyes merge two pipelines and enable pigging from each line but can only be pigged in one direction. Diverting pipeline wyes enhanced the functionality by allowing pigs to pass in both directions, but the designs resulted in awkward, bulky packages with high costs and design limitations for larger sizes. A unique internal element was incorporated into the standard wyes that allowed for bi-directional pigging without significantly deviating from the normal geometry and price range of a standard pipeline wye fitting. The design included structural analysis, fluid flow analysis, the development of the complex internal geometry into a machine capable part, and the incorporation of gear drive system to allow operation for subterranean and subsea installations. Prototypes were built, factory and flow loop tested, and are currently installed and operating in field applications.

Immediately after an oil spill incident, the end user approached company for potential solutions to contain the leak. A solution was developed to lock and also seal over a connection structure immediately below the fractured pipeline. Rigorous review meetings direct with end users were conducted, and a design team of six engineers and designers were led to produce a finished design in under two weeks.

Multiple deepwater flange connections in South American waters were deemed high risk due to an improper material selection. An ROV operable clamp was developed to secure the flange connection without replacing fasteners. The system which included a recoverable installation tool was built and successfully tested.

A pair of large diameter gas pipelines supplies gas to millions of homes in Europe. As a contingency repair option, a repair clamp was designed to secure several meters of damage and replace the full structural integrity of the pipeline in case the pipe is entirely compromised. The project involved coordination with companies from six different countries and the final product, a 200,000 pound, 11 meter long repair clamp, is considered possibly a world’s record. This landmark project required a full set of engineering capabilities involving:

  • Detailed design
  • Material selection and specification development to a stringent set of requirements
  • Weight optimization
  • Critical risk assessments
  • High level finite element analysis
  • Incorporation of key components from other vendors
  • Detailed interface with both the maintenance/storage contractor as well as main repair contractor
  • Design package that included eight design reports reviewed by the customer and international third part review agency

A unique solution was required for our customer to seal a leak on a 10” nom 1500 ASME Class subsea flexible pipe fitting located in the North Sea. A diverless non-structural repair clamp design to meet customer specifications was created. Consultation with the manufacturer of the fitting was required to assess additional pressure end loads resulting from sealing the fitting. Other unique customer requirements were non-standard forging material, permanent mechanical seal lock, temperature compensation system, pressure testing at 34°F, non-standard seal material, and deployment of clamp in the inverted position.

A 12” pipeline was dropped in 6000 feet of water during a pipe lay in the Gulf of Mexico. A custom 12” nom- Class 1500 hydraulically set pipeline retrieval connector was designed to recover the pipeline. The connector was a sleeved fitting equipped with internal locks and recovery hook. It was designed to ASME Section VIII Division 2 rules complete with finite element analysis performed on the hook. The connector was factory load and pressure tested and offshore installation supervision included.

An emergency 12” Class 1500 fabricated repair clamp was required for installation at diver depths in South American waters. Standard repair clamps were manufactured from ring forgings, however, the emergency nature of the repair required a fabricated solution. The clamp was to encapsulate a 12” Class 1500 subsea flange set and seal on adjacent pipeline. The design and analysis was unique due to larger deflections at the longitudinal seal due to the compliance of the fabricated version. Coordination and interface with the weld department was required for new weld procedure qualifications based on customer specifications, material of construction and section thicknesses.

Managed design of a 20” Class 1500 Hot Tap for installation in Canadian waters. The cold water installation on the subsea gas pipeline required four seal materials to be tested for explosion decompression, corrosion inhibitor chemical compatibility, cold temperature performance and annulus pressure testing.

A gasket on a 12”- Class 900 subsea flange failed on a pipeline in the Gulf of Mexico at a depth of 1100 feet. A unique solution was required by our customer to optimize the weight of the repair clamp and allow hard suit divers to manage the installation. A split sealing clamp was designed to collar and seal on the outside diameter on the flange pair in order to minimize weight. In doing so, however, the configuration would allow the gas to leak through the stud clearance holes of the flange. A solution was proposed to combine the hydraulically set seals with the injection of a two part curable epoxy.

A 12/18/20” Class 1500 internal hydraulically set contingency pipeline retrieval connector was required for our customer. The connector was unique in that the customer specifications required that the weight be optimized and that it was to lock and seal within the pipe inside diameter rather than conventional outer pipe interface. Further it was required that one tool be used to recover 12, 18 or 20” diameter pipelines. The connector was a sleeved fitting equipped with internal locks, seals and recovery hook. The connector was designed to ASME Section VIII Division 2 rules complete with finite element analysis performed on the hook. The connector was factory load tested to 2 million pounds at 12 degrees while sealing test pressure. Additionally the tool was required to have a mechanical override in the event of hydraulic failure.

Corrosion, accidental damage, and storms are some of the many factors that can lead to leaking connections and other issues with offshore pipelines. The costs and complexity of repairs increases dramatically in deepwater applications. Entagral Engineering has a extensive of experience with pipeline repair systems and tools. 

Entagral’s core design experience is in engineered pipeline products.  We support inventory product lines, lead product development to extend size and capacity ranges, and also develop custom engineered solutions for unique and challenging scenarios.