Subsea Processing and Cold Flow Technology for Extended Oil and Gas Developments Samuel Paul Flow Assurance Engineer Ratnam Sathananthan Global Flow Assurance Manager / Technical Authority 20 th June 2018 1 Subsea 7-2018
Cold Flow (Temperature Independent Transportation) 2 Subsea 7-2018
Cold Flow System development purpose Of the many challenges we face in multiphase flow transportation system, the KEY ones are how do we manage Hydrate and Wax. Today we manage by: use of chemicals Passive insulation, WET and DRY insulation in (PIP ) Actively heated flowlines This so far in the last twenty years take us as far as 70km ( in 1998 ) in oil field, insulated system. 145km gas field tie back with continuous injection of hydrate inhibitor. So answer is temperature independent transportation ie COLD FLOW In my Halliburton day s I started looking for a solution for Long Distance Tie back. Now we are ready to offer the technology to the industry. 3 Subsea 7-2018
Cold Flow - Late 90 s Concept Testing 4 Subsea 7-2018
Wax and Hydrates 5 Subsea 7-2018
Introduction and the requirement for cold flow 6 Subsea 7-2018
Going Deeper and Further Improved Technology for Normal, Deep and Ultra deepwater field development and extended length tie-backs 7 Subsea 7-2018
Background - Current Practice Current philosophy: Keep the fluid hot to avoid wax and hydrates problems Current methods: Wet insulation Dry insulation (pipe-in-pipe) Active heating (electrical, hot water circulation) Conventional Insulation Pipe-in-Pipe Insulation Hot water (indirect) heating 8 Subsea 7-2018
Required U Uid Value Background Example - Current 'U' Practice value required for a length of Pipeline 14 12 (for given fluid and thermal properties) Example Relationship Between U Value and a Length of Pipeline 10 8 6 4 2 0 0 10 20 30 40 50 Pipeline length (km) 9 Subsea 7-2018
Background - Insulation We have reached the practical limits of current insulating materials 10 Subsea 7-2018
Direct Electrical Heating Topsides Power Piggy-back cable Anodes Connection Flowline Current transfer zone 11 Subsea 7-2018
Trace Heated Pipe-in-Pipe Total Islay Project Pre Qualification DnV RP A 203 Qualification Fit for Service 12 Subsea 7-2018
Tie-backs vs. Offloading? SPSO (Subsea Production, Storage, Off-loading)? Electrical Trace Heating Insulated Pipe 13 Subsea 7-2018
The Way Forward Cold Waxy Slurry Outlet Hot Waxy Crude Inlet Treatment Loop Ambient Water @ 35-40 Deg F 14 Subsea 7-2018
If we can t keep it hot, can we flow it cold? Wax and Hydrates Wax is a problem when it deposits of the pipe wall, restricting flow, potentially forming a wax plug during pigging. Hydrates can agglomerate together to form a plug. Both only a problem when they agglomerate. 15 Subsea 7-2018
Wax and Hydrate Agglomeration Wax: Wax only deposits on the pipe wall during formation, ie. when oil is cooling down. Once the oil is at ambient temperature - no further deposition on to pipe wall. Any wax particles present in the fluid will be transported in suspension and will not deposit on the pipewall. Hydrates: Well-stream Low dosage hydrate inhibitors exist to manage hydrate formation and agglomeration. Subsea Separation Gas Oil Combined Hydrocarbons Only cost effective at low water rates. Requires bulk water removal upstream of injection point. Water 16 Subsea 7-2018
Cold Flow and Subsea Processing 17 Subsea 7-2018
The Cold Flow Concept Two key processes required: 1. Bulk water removal: o Associated water clean-up/reinjection Hydrate management = LDHI 2. Wax Deposition Management: o Fluid cooling o Regular removal of wax deposition 18 Subsea 7-2018
Wax Deposition Control Several novel wax deposition removal technologies in development. Industry standard? Regular pigging Subsea installations with extended tiebacks will require automated multiple pig launching 19 Subsea 7-2018
Wax Control System - Frequent Pigging - Simplified P&ID 1. Frequent Pigging Regular insertion of cleaning pigs into export line using an Automated Multiple Pig Launcher (AMPL) with large pig magazine (50+ pigs) Pro s : Low cost, flexible, proven technology Con s : Large # of pigs, frequent pig receiving 20 Subsea 7-2018
Wax Control System Frequent Pigging Field Layout 2 off AMPL with large capacity pig magazine Export line cooled down to ambient 1. Initiate pig operation based on measured wax thickness, experience, or production chemistry 2. Insert cleaning pig from AMPL. SPU Spool Export Pipeline 3. Pig removes depositied wax in pipe. Oil/ wax slurry to follow flow to host or shore. 4. Cleaning pig received in pig receiver on shore, or at host. 21 Subsea 7-2018
Early principle for Cold Flow Concept «Wax Eater» (1999) Data Monitoring System Chilled Water Cooler (C-270&C-272) Oil Feed Pump (J-102) Treatment Loop Oil Storage (T-100) (Oil Heater below tank) Flowline Loop Cooling Water Tank (T-200) 22 Subsea 7-2018
Cold Flow Wax Control Loop Schematic PIGGABLE BEND COLD FLUID FROM PIGGING LOOP PIGGABLE BEND 2. Continuous pigging in pig loop Pro s : Long time between pig receiving shore, less pigs to travel through export line. COLD FLUID OUT HOT FLUID IN BARRED TEE VALVE 2 NORMALLY CLOSED PIGGABLE Y PIECE 2 VALVE 1 NORMALLY OPEN BARRED TEE FULL BORE PIGGABLE SPECIAL NON- RETURN VALVE MINIMISE DISTANCE PIGGING DIRECTION Con s : PIGGABLE Y PIECE 1 Higher cost compare to frequent pigging, new technology. PIGGABLE BEND PIGGABLE BEND HOT FLUID TO PIGGING LOOP 23 Subsea 7-2018
Cold Flow System Wax Control Unit PFD GAS OIL TOWHEAD WAX CONTROL UNIT BUNDLE TOWHEAD MULTIPHASE PUMP STATION TO HOST FACILITY PIG LAUNCHER FB, NC NO FB FB FB FB WAX CONTROL PIGGING LOOP SEAWATER DISCHARGE SEAWATER INTAKE FILTER SEAWATER DISCHARGE COOLING WATER PUMPS 24 Subsea 7-2018
Cold Flow: Wax Control System SPU Trailing Towhead Leading Towhead Bundle Export Pipeline 25 Subsea 7-2018
Cold Flow: Wax Control System Bundle Seawater cooling annulus 26 Subsea 7-2018
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Large Scale Testing 29 Subsea 7-2018
Cold Flow 2018 Large Scale Testing Rig System Schematic 30 Subsea 7-2018
Subsea Processing Facility (required precursor) 31 Subsea 7-2018
Advances in Subsea Processing 32 Subsea 7-2018
Cold Flow System Overall Field Schematic 33 Subsea 7-2018
Cold Flow System Subsea Processing Facility PFD 34 Subsea 7-2018
WET GAS Cold Flow System Subsea Processing Facility PFD BULK GAS SEPARATION (GAS HARP) BULK WATER SEPARATION (DUAL PIPE SEPARATOR) WET GAS OIL CHRISTMAS TREE WELL STREAM PRODUCTION HEADER DE- SANDER SAND STORAGE SAND TREATMENT LIQUID FROM SAND OILY WATER OILY WATER TREATMENT MIXER CFU GAS WITH OIL SEAWATER INTAKE TOWHEAD FB, NC PIG LAUNCHER NO FILTER FB FB FB FB WAX CONTROL UNIT BUNDLE WAX CONTROL PIGGING LOOP TOWHEAD SEAWATER DISCHARGE SEAWATER DISCHARGE MULTIPHASE PUMP STATION TO HOST FACILITY PRODUCTION WELL COOLING WATER PUMPS PRODUCED WATER REINJECTION MIXER CFU OPTIONAL DISCHARGE TO SEA TREATED PRODUCED WATER DISCHARGE TO SEA DEGASSER RAW SEAWATER TREATMENT SEAWATER INTAKE SEABOX WATER DUMP TO SEA CONCENTRATE DISPOSAL TO SEA FROM PARALLEL WATER TREATMENT UNITS WATER INJECTION PUMPS CHRISTMAS TREE TREATED SEAWATER H.F FILTERS FEED PUMP BACKWASH EJECTOR REVERSE OSMOSIS MEMBRANES WATER INJECTION SUCTION HEADER INJECTION PUMP WATER INJECTION DISCHARGE HEADER BACKWASH DISPOSAL TO SEA WATER INJECTION 35 Subsea 7-2018 WELL
Design, Fabrication, and Installation More subsea functions Larger subsea structures or more structures Larger weights requires larger vessels and cranes Low cost installation method Less restricted installation weather windows 400t Gullfaks WGC template using the Oleg Strashnov HLV 36 Subsea 7-2018
Towed Pipeline Bundle Systems 81 bundles in 37 years 7.6km individual length 28.7km in series 42 to 410m water depth Longest tow 1000 km Up to 56.4 carrier Up to 550 Te towhead 160 C Design Temp Clair Ridge Wick Scotland Cormorant Buckl Piper and Saltire Claymore Scapa Murchison Gannet Bruce Åsgard Osprey Heidrun Frigg East Keith Thel ma Cyrus, Farragon, Andrew Alba Gullfaks Leadon Embla Dan Denmark Norway 37 Subsea 7-2018
Modified Controlled Depth Towing Method 38 Subsea 7-2018
Landing of the SPU 39 Subsea 7-2018
Modular system for integration of functions 40 Subsea 7-2018
Standardized modularization of new components 1 2 3 Modularization Slot Product Model Module into slot in structure 41 Subsea 7-2018
The layout of the plant 42 Subsea 7-2018
Solutions for any Subsea Factory 43 Subsea 7-2018
Unlocking Marginal Reserves 44 Subsea 7-2018
Conclusions A market now exists for extended length tie-backs Traditional approach of passive thermal insulation materials and active heating can only take you so far. For development in the arctic where manned platforms are not possible, temperature independent Cold Flow fluid transportation or subsea storage are the only options. A cold flow solution has to addresses the management of hydrates and wax. Hydrates can be addressed by bulk water removal (and associated processing) and continuous injection of low dosage hydrate inhibition. Wax deposition can be addressed by deliberate cooling and frequent pigging. Controlled depth tow method allows for safe and cost-effective the installation of the necessary heavy subsea production system without the need for heavy lift vessels. 45 Subsea 7-2018
Cold flow and Subsea Processing for Extended Oil and Gas Tie-backs 46 Subsea 7-2018
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