An umbilical is generally thought of as a lifeline. Most often, a lifeline from a fetus to a mother or a deep sea diver to oxygen. Within umbilicals such as these, are the vital components that are needed for humans to survive and thrive. Although these may be the most common examples of umbilicals, there is an innovative technology that now uses umbilicals to link surface and sea floor oil and gas equipment, providing the absolute essentials that are needed for them to operate effectively.
Umbilicals are the lifeline of subsea equipment, providing things such as electric and fiber-optic signals, electrical power and hydraulic and chemical injection fluids to a subsea unit. They are specifically designed to withstand seabed temperatures and harsh environments. Enclosed within an outer ring specially designed for their environment, the inside is specifically designed for the intended client, whether it be an integrated umbilical or a hybrid umbilical. Integrated umbilicals house multiple connections, while hybrid umbilicals contain flowlines.
LLOG Exploration Company, based out of Covington, LA is the largest privately owned oil producer in the United States, grossing over 49 million barrels of oil production last year. LLOG primarily uses umbilicals on their development and production side of business, as they exclusively use wet trees, so every one of their developments has at least one umbilical. They are run from the host facility, where production is processed, to the wells, which could range anywhere between 3 and 34 miles away. LLOG’s umbilicals have steel tubes (typically ½ – 1 inch diameter) that provide hydraulic power/control or production chemicals, such as corrosion, paraffin, asphaltene or hydrate inhibitors. These are injected into the well or flowline. Nearly all of LLOG’s umbilicals have copper wire (with insulation) to provide power for well controls or receive signals from the wells. Some of the umbilicals also use fiber optics which provide better data transmission.
LLOG generally bids out for their umbilical fabrication, so they have had several manufacturers. Aker Solutions is one of the companies that is supplying the production and gas lift umbilicals on LLOG’s Buckskin project. Buckskin is the first development for LLOG in the Lower Tertiary Wilcox trend and is located on Keathley Canyon blocks 785, 828, 829, 830, 871 and 872 in approximately 6,800 ft. of water. It is large in size and anticipated to bring in 5 billion barrels of oil in-place. In the first phase, they will drill and complete two development wells in Keathley Canyon 829 and then have a six mile tie-back to the Lucius platform in Keathley Canyon 875. After completion of the first phase, there will possibly be as many as 12 additional wells that are needed and will all be tied-in using umbilicals.
Umbilicals are a dependable and valuable asset for LLOG. “LLOG’s umbilicals have worked well. Occasionally, individual tubes have clogged or we lose signal on an individual wire. These individual failures are generally not a problem since we put spare tubes and wires into every umbilical and we have never been forced to replace an entire umbilical,” says Rick Fowler, LLOG’s vice president of deepwater projects.
Aker Solutions has delivered more than 550 umbilicals worldwide, over a span of 20 years. Their special system for packaging tubes and cases minimizes longitudinal forces, while offering greater internal and external strength, high fatigue capacities and with no restrictions on geometry. They offer Power Umbilicals and Cables, Steel Tube Umbilicals, Steel Tube Flying Leads, Direct Electrical Heating Systems and Integrated Production Umbilicals. “The umbilical process is fascinating,” says Fowler.
Aker Solutions’ Power Umbilical Cables are a highly advanced way of providing power and controls to subsea processing and boosting systems. They are well suited to either fixed platforms or floating units. The Steel Tube Umbilical designs provide a reliable and durable way of connecting onshore or offshore hosts with subsea facilities. They typically provide hydraulic fluid for control, various chemical fluids for injection into the flowline, electrical power and electrical or fiberoptical signal transmission. The Steel Tube Flying Leads are loose bundle type and umbilical type flying leads with soft profiles to enhance flexibility. The Electrical Heating Systems are designed for use in flow-lines and pipelines to prevent the formation of wax and hydrates, which could slow the stream of hydrocarbons. Integrated Production Umbilicals (IPU) combine the umbilical function and the flowline and offers an alternative flow heating solution.
“LLOG also uses umbilicals during some drilling and well operations to send signals/ power from the rig to the well. These umbilicals are used temporarily and have much shorter distances (about the water depth or 1,000 to 7,000 feet). LLOG would not own these umbilicals as they would be owned by the rig/intervention companies,” says Fowler.
Whether umbilicals are used temporarily or for long-term, for short distances or long distances, for one function or several, one thing is certain: umbilicals are a critical link to deep sea oil and gas exploration and production. The efficiency and accuracy that they provide is invaluable to the companies that utilize them and the industry as a whole.
Sarah Skinner is a graduate of Louisiana State University with a degree in English. She has been a technical writer and editor in the oil and gas industry for over ten years in Houston and in Louisiana. She currently works as a technical writer for a pre-cast concrete construction company in Louisiana that builds blast-proof buildings for petrochemical plants.
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