from ocean to cloud DUAL-CONDUCTOR CAPABILITIES IN WET PLANT DESIGN QUALIFICATION SEATRIALS

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1 DUAL-CONDUCTOR CAPABILITIES IN WET PLANT DESIGN QUALIFICATION SEATRIALS Maurice E. Kordahi, Jeremiah Mendez, Ralph J. Rue, Michael M. Sanders, Robert K. Stix, Ryan Wilkison (TE SubCom) TE SubCom, 250 Industrial Way West, Eatontown, New Jersey USA Abstract: Wet plant components with independent dual-conductor capability allow nontraditional undersea optoelectronics to be efficiently incorporated into a standard undersea telecom infrastructure without affecting telecom reliability. This capability, provided by a suite of undersea qualified, high-reliability components, serves several special applications for Oil & Gas sensor systems and undersea scientific observatories in their ability to provide remote sensing, remote data collection, and unique system powering architectures using the additional power conductor integral to the telecom cable. As part of the development and qualification, jointing trials along with two separate sea trials were conducted aboard SubCom s cable ships in the Atlantic Ocean off the East Coast of the United States. 1. BACKGROUND Newly developed dual-conductor undersea capability provides a proven and valuable design option for system designers enabling several new applications. Unlike traditional telecom cables that use a single conductor and a seawater return path, the added powering functionality provided by dual-conductor cabling along with a suite of undersea-qualified high-reliability components is well-suited for special applications in Oil & Gas system, off-shore sensor systems, and undersea scientific observatories. [1],[2] The additional electrical power path is provided by means of an outer concentric conductor and corresponding layer of insulation applied to a standard telecom cable (Figure 1). Subsequently, both electrical paths may be routed through repeaters and Branching Units (BUs). Three-cable and four-cable BUs can contain up to three independent power paths through a single undersea housing. [3] All are deployed with standard cable ship equipment and machinery. Extensive qualification testing of SL Dual- Conductor Cable (DCC) was performed on the lightweight or deep-water design. The majority of the qualifications for the armored and protected cable designs (DA, SA, LWA, and SPA) are based on the exact similarity of these designs to the existing SL21 cable family designs. Figure 1. SubCom dual conductor cable Specific qualification tests deemed appropriate for the armored and protected cable designs, such as the Crush Test, were performed on trial lengths of these cables and successfully completed. Copyright SubOptic2013 Page 1 of 6

2 2. ADVANTAGES & APPLICATIONS Dual-conductor cable (DCC), BUs, and repeaters with dual power paths allow nontraditional undersea optoelectronics to be efficiently incorporated into a standard undersea telecom infrastructure without affecting telecom reliability. [4],[5] Figure 2 shows an example network taking advantage of SL DCC and a four-cable BU to connect and power both commercial communications and a science observatory application. [6] Of course, three-cable BUs also readily accept dual-conductor cables and their multiple power-path functionality. 3. SHIPBOARD JOINTING DCC jointing is required for installing and repairing undersea systems containing newly-developed dual-conductor long-haul cables. Similar to conventional singleconductor jointing, this jointing takes on a modular approach whereby the core cable joint uses end-specific termination hardware kits along with various endspecific armor termination kits depending on the cable type encountered. [8] Several DCC Millennia Joints and couplings have been successfully built and/or molded aboard ship at-sea. These activities consisted of three (3) DCC Millennia Joints and four (4) DCC Millennia Couplings. X-ray and visual inspections were also performed. In DCC jointing, the outer conductor path is routed in the polyethylene insulation layer that traditionally insulates the primary conductor path (Figure 3). This enables design re-use of all of the outer protection hardware presently used for SL21 cables. Figure 2. Example network serving both commercial and science applications. A single 4-cable BU or two 3-cables BUs can be used depending on sites to be connected. An added advantage to selection and design of the BU, DCC, couplings, and DCC jointing approach is that they take advantage of existing infrastructure, equipment, and training. They balance customers needs for current product and system support as well as capital invested in inventory and tooling. This serves to expand capability, minimize cost, and maintain both quality and reliability. [7 ] Figure 3. Second-conductor bypass With the exception of the outer-conductor operations, the joint follows the same steps used for existing cables. See Figure 4 to Figure 7. Copyright SubOptic2013 Page 2 of 6

3 Figure 6. Completed molded DCC joint Figure 4. DCC joint in lower half of mold Figure 7. X-ray evaluation of DCC joint Figure 5. DCC bypass conductor visible (near end of polyethylene sleeve) Once the molding operation is completed, all other operations follow commonly used procedures. For example, the armor packages for SL DCC joints are the same as existing SL21 armored joints. 4. SEA TRIALS As part of the development and qualification of these new products, separate sea trials were conducted. Each one was undertaken using a SubCom cable ship in the Atlantic Ocean off the East Coast of the US. The shallow-water trials were performed in approximately 150- meter water depth while the deep-water trial was performed in approximately 2500-meter water depth with varying sea conditions. Copyright SubOptic2013 Page 3 of 6

4 Shallow-Water Sea Trials The shallow-water trials included two objectives. First was to demonstrate the ability to handle DCC cable and joints. Second was to manage a four-cable BU and its 1-km lengths of SL21 Single Armored cable through shipboard machinery, deploy the BU into shallow water, and demonstrate successful placement of the BU and its 4 cables onto the seabed in their engineered position. The sea trial cable grounds were located approximately 60 miles off the East Coast of the United States at a 150-meter water depth. Seas during cable operations were between Sea State III and Sea State IV. For the first objective, with the DCC cable product already successfully tested and qualified, shipboard trials were undertaken using double-armored (DA) cable to verify handling and operational performance including deployment and recovery. Two armored DCC joints using Millennia jointing technology were incorporated in the trial cable. The cable assembly was deployed to 150 meters and subsequently recovered. All operations were completed successfully and all handling requirements were met. For the second objective, all respective cables were integrated to the BU using couplings. Each cable was prepared optically and measured via one-way OTDR at the beginning and at the end of the trials as an optical integrity check. Figure 8 shows the assembled sea trial body ready for deployment. The BU sea trial operations included deployment of cables #1 and #2, deployment of the four-cable BU, deployment of cables #3 and #4, a Remotely Operated Vehicle (ROV) survey, and recovery of cables and BU. Figure 8. Four-Cable BU Assembly ready for deployment A diagram depicting the deployment operation is shown in Figure 9. As in the case of 3-cable BUs, the four-cable BU bypassed the cable drums and was sent overboard (Figure 10). Figure 9. Example positioning of cables for deployment This was a mechanical trial and no optical monitoring was required or performed during the trial. BU cable payout was performed at about 0.3 knots. After successful deployment and inspections, the recovery operation commenced with tensions ranging from 4000 to Deep-Water BU Sea Trial The deep-water sea trial cable configuration consisted of 2 lengths of SL21 SPA cable and 2 lengths of SL17 SPA cable. Deployment payout speed was maintained at 0.5 knot. Once all cables were on the bottom, the vessel was positioned in the area of the BU touchdown and a TE SubCom ROV was deployed. The ROV initially located the two shipboard side cables of the BU and followed them until identifying the BU position on the seabed. The BU was Copyright SubOptic2013 Page 4 of 6

5 observed to be lying nicely flat on the bottom. Subsequently, the recovery operation commenced at speeds of about one knot and tensions ranging from 5500 to 6000 lbs. The operation continued until the BU eventually appeared at the water s surface. Figure 11 shows the BU at the surface during recovery. Figure 10. Deployment of BU and/or molded successfully. These trials successfully demonstrated dual-conductor capabilities. In addition, separate deep-water and shallow-water sea trials demonstrated and confirmed the feasibility of handling, deployment, and recovery of key dualconductor hardware. In-situ inspections using ROVs showed successful placement of the BU on the seabed with all cables conforming. In each case, the recovery of the trial cables was successful with no issues observed with the cables or the BU. These are the first known trials to successfully four-cable BUs on the seabed in pre-engineered positions using a single vessel with no support. Figure 11. Recovery of BU With all cables back onboard, a set of OTDR measurements were taken for all four cables to compare against the baseline measurements collected before deployment. These measurements showed excellent results, with no significant changes to the optical behavior on any of the sea trial cables. 5. SUMMARY Dual-conductor BUs, Repeaters, SL DCC, and SL DCC joints enable the supply of different and independent power levels from independent sources via separate power paths. This gives system designers enhanced flexibility in meeting diverse applications while economizing on infrastructure. A number of both DCC Millennia Joints and DCC Millennia Couplings were built 6. ACKNOWLEDGMENTS We are grateful for the diligent support, contributions, and guidance we received from our colleagues too numerous to name individually. 7. REFERENCES [1] Kordahi ME, Mendez J and Stix RK, Undersea Information Pipeline Solutions for Offshore Oil & Gas Fields, SubOptic 2010, May 2010, Yokohama, Japan. [2] Fullenbaum M, Hazell N, Waterworth G, Doyle L, Submarine Fiber-Optic and DC Power Solution for Ultralong Tieback Submarine Fiber, OTC 2007, Offshore Technology Conference, April-May 2007, Houston, TX, USA. [3] Kordahi ME, New Tools for Undersea Networks, ITU Green Standards Week Workshop, September 2011, Rome, Italy. [4] Kordahi ME, New Tools for Multilayered Undersea Copyright SubOptic2013 Page 5 of 6

6 Telecommunication Networks, Sea Technology Magazine, July [5] Fullenbaum M, Opto-Electrical Solutions for Offshore Fields, Subsea Controls and Data Acquisition, Society of Underwater Technology, SCADA , June 2006, Toulon, France. [6] Thomas R, Tully G, Spalding M, Buffitt D, Mendez J, Munier R, Long Term Real Time Observatories for Environmental Monitoring in Offshore Drilling and Production Areas, SubOptic 2013, April 2013, Paris, France. [7] Kordahi ME, Mendez J, Spalding MA and Stix RK, Innovative Jointing & Stable Technology Closer Than We Think, SubOptic 2007, May 2007, Baltimore, MD, USA. [8] Kordahi ME, Mendez J, Sanders MM, Stix RK, Wilkison R, Undersea Jointing Progress Gathering No Moss, SubOptic 2013, April 2013, Paris, France. Copyright SubOptic2013 Page 6 of 6