Why Pig subsea production flowlines? Illustration of single production line * Pazflor Miocene development Conclusions 12/04/2016

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Chester Smith
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1 Pigging needs for subsea production lines Diane EL GEMAYEL / Christian FOUILLOUT AGENDA Why Pig subsea production flowlines? Illustration of single production line * Pazflor Miocene development Conclusions 1

2 Why pig subsea production flowlines? To keep the pipe wall clean of deposits or solids To remove any restriction to flow To improve the effectiveness of corrosion control by chemical treatment (corrosion inhibitor, biocide) To manage liquid accumulations To keep liquid hold up within manageable limits To prevent for localizedcorrosion corrosion (stagnantwater) To assess the pipeline condition with smart pigs To detect metal loss / corrosion To detect cracks Subsea architecture and pigging PROS CONS DUAL FLOWLINE LIMITED OPEX CAPEX FIELD PROVEN ROUTINE PIGGING FEASIBLE REVERSE FLOW CAPABILITY SHORT FALLS (wells shutdown) SINGLE FLOWLINE CAPEX REDUCTION HIGH OPEX (Field Service Vessel) LESS EQUIPMENT ON TOPSIDES SUBSEA PIG LAUNCHER LIMITED EXPERIENCE IN DEEPWATER OPERATIONAL RISKS 4 2

3 Case study Pazflor Gas-Lift Floating Production Storage Offloading Liquid Production Riser Gas Risers Multiphase flow line M42 M41 S10 P40 S20 S30 MIOCENE FLOWLINES PAZFLOR MIOCENE SYSTEM Carbon steel 10 Water depth : ~ 800 m Wall thickness : 11.2 mm (3 mm c.a.) Multiphase single line Continuous inhibition with Corrosion Inhibitor Subsea gas/liquid separator & boosting In line Inspection planned to prove integrity Layout Pazflor Miocene P20 Line Length P10 9 km P20 10 km P30 8 km P10 P30 FPSO SSU : 2 3 Km 6 3

4 Subsea separation & boosting unit Flowline operated at low pressure for efficient well s lift Liquid pumped at high pressure Diameter 10 for flowline and liquid riser By pass valve : closed in production mode Pigs to be run from FLET to Topsides PC Sep gas Riser top Two 6 Gas risers Riser top PMV PWV Choke valve ROV- operated RO Separator liquid LAH 23bar LAL LC Pumps Typical pressure bar By pass valve Closed ROV- operated 10 Liquid riser (oil + water) Typical pressure 120 bar 7 Subsea pigging operation main facts Operation planned Cleaning of the flowline With SPL + Downline + Field Support Vessel In line inspection with smart pig Main requirements : Pigging Subsea to FPSO No Hydrocarbon return on FSV Bi directionality (reverse flow) Pig propelled using treated seawater Operations in Shutdown conditions Complex, risky & costly operation 8 4

5 Equipment required for the operation Subsea Pig Launcher and tie in to FLET Mudmat module ~ 40 T Pig launcher ~ 8 T Flexible jumper 100 m ~50 T Downline equipment 4 x 1000 m flexible Emergency Quick Disconnect system Tensioner + Reel frame T Aids Sheave + Clamp + DMA Mudmat Module Pig Launcher Module Jumper FSV equipment Nitrogen skid Pumps (seawater lifting and Circulation) Chemical injection skid 9 Operational sequence Step 1 : Shut down and depressurization via SSU Step 2 : Inertisation (with Nitrogen) Step 3 : Flooding and by pass of the SSU Step 4 : Progressive cleaning program Step 5 : Intelligent pig run Get quality data!! Step 6 : Re start of production 10 5

6 Conclusions Operational pigging IS part of pipeline integrity management Subsea & Deepwater conditions emphasize pigging operation constraints Subsea pigging: Has to be anticipated in Design phase Generates complex & risky operation Requires additional time and loss of production with cost impact 11 Thank you!!! Questions? Pazflor SPL Animation by STAT marine Engineering 12 6

Havbunnsproduksjon. NTNU, 15 april 2013 Eldar Lundanes System Responsible for Controls and Data Management, Eastern Region.

Havbunnsproduksjon. NTNU, 15 april 2013 Eldar Lundanes System Responsible for Controls and Data Management, Eastern Region. Havbunnsproduksjon NTNU, Eldar Lundanes System Responsible for Controls and Data Management, Eastern Region Objectives The student shall be able to describe, with respect to a subsea production system;