Lett Brønnintervensjon Hans J Lindland FMC Kongsberg Subsea
Why Light Well Intervention? Reservoir recovery is significantly lower (oil) for subsea wells than for platform wells Cost for drilling units too high New well technology for through tubing work Smaller dynamically positioned semis and monohull vessels available Number of subsea wells are increasing
Increased Oil Recovery with LWI The Value (Norwegian Continental Shelf) 17 subsea fields in NCS have 5.7 Billion bbl oil recoverable (at 36% recovery rate Source NPD) Increase recovery rate to 44% (to match platform wells) gives 1 Billion bbl extra oil Value 200 Billion NOK LWI a major contributor to increase recovery
Background DEMO 2000 Joint Industry Study as basis for Light Well Intervention on NCS Study topics: Concept Well Control Risk / HSE Rules / Regulations Vessels & equipment Market
Classes of Well Intervention VESSEL(A) Light intervention VESSEL(B) Medium intervention VESSEL (C) Heavy Intervention
Time Comparison WL Service (From DEMO 2000) 250 200 Operation Hours 150 100 Preparation Transit Anchors 50 0 Anchored Semi DP Semi Overall time for a 35h wireline operation Vessel/ Riserless
Well Intervention Operations Verify fluid properties from different perforated zones Install / manipulate various mechanical devices (valves, plugs, screens etc.) Well stimulation Re-perforation Well abandonment Production problems - Water breakthrough - Gas breakthrough - Formation damage - Sand production - Scale
Riserless Light Well Intervention Main System Features Subsea flushing, no well fluid to surface Riser back-up Toolstring to 22m HXT & CXT 7-1/16 bore; 10k psi ROV hydraulic override of all valves
Integrated Control Wireline Control Cabin & Cyberbase 0.125 slick line 7/32 braided line Network Signals Network Signals G&HPU Power & Controls Logging & Measurement Signals Power & Controls Logging & Measurement Signals Dual Skid Single Skid 5/16 drum 5/16 to 15/32 drum Subsea Grease Pumps WOCS Grease Injection & Hydraulic Controls Subsea Umbilical
The Subsea Wireline System Cyberbase multi purpose control unit Stainless steel fire resistant shell Zone 2 rated Logging facilities
LWI Status in Norway Subsea wireline can be performed from DP semi (MOU Class) or mono hull? System tested Shallow water test at CCB Onboard Regalia Capable of handling intervention with riser Work for Statoil September 03
Test & Qualification of RLWI Qualification and test program levels Component Subsystem level (FAT and Extended FAT) System level (integration and shallow water) Fjord test with vessel and offshore crew The program will ensure efficient and safe operation of the system on live wells offshore
Qualification and verification testing Testing preparation at Kongsberg Site integration test Procedures for testing System verification Shallow water testing CCB Subsea grease injection qualification/contingency Five weeks in Onarheimsfjorden with Regalia Modifications and testing summer 03 CCB Husøy Forus
Shallow water test at CCB steps Run LRP with lubricator Circulate out seawater/air by pass etc. Function test valves - observe with ROVs Run wire line - pump grease w/various P-T-Q Test disconnect umbilical/drive off case Retrieve equipment and refurbish
Testing of RLWI Equipment Pressure Control Head Wireline ram Lubricator
Testing at Husøy