SPE LONDON MEETINGS 2013 SUBSEA PRODUCTION AND FLOW ASSURANCE BY; SACHA SARSHAR,CALTEC www.caltec.com
SUBSEA PRODUCTION &FLOW ASSURANCE • WHY SUBSEA PRODUCTION ? • KEY PARAMETERS • SUBSEA PROCESSING OPTIONS • FLOW ASSURANCE IN WELLS • FLOW ASSURANCE IN SUBSEA PIPELINES/RISERS • HISTORY OF SS SEPARATION & BOOSTING SYSTEMS • FIELD EXAMPLES • THE FUTURE NEEDS AND ASPIRATIONS • TECHNOLOGY GAPS/CONCLUSIONS
DEEP WATER APPLICATION A TYPICAL SUBSEA PRODUCTION Production, manifolding, gas lift, water injection, SYSTEM ,separation, pumping, compression 22 February, 2013 Presentation title 3
A TYPICAL SUBSEA PRODUCTION SYSTEM 22 February, 2013 Presentation title 4
WHY SUBSEA PRODUCTION?,KEY PARAMETERS • DEEP/DEEPER WATER FIELDS,HIGH COST OF MORE THAN ONE DEDICATED PRODUCTION PLATFORMS • SHALLOW TO MEDIUM WATER DEPTH; TRANSPORT OF FLUIDS FROM SATELLITES OR NEW FIELDS TO A HOST PLATFORM • HOSTILE ENVIRONMENTS, LONG DISTANCE TRANSPORT TO A MORE BENIGN ENVIRONMENT • DEEP WATER/LONG DISTANCE PIPELINES, PRESSURE LOSS RESTRICTING PRODUCTION &RECOVERY+OTHER FLOW ASSURANCE PROBLEMS • RISER GENERATED PROBLEMS
SUBSEA PRODUCTION,MAIN BENEFITS • INCREASED TOTAL RECOVERY • ENABLING PRODUCTION FROM DEEP WATERS AND HOSTILE ENVIRONMENTS • LOWER CAPEX/OPEX-CONVENTIONAL PRODUCTION PLATFORMS IN DEEP WATERS HAVE MUCH HIGHER CAPEX &OPEX • ENABLES LONG DISTANCE TRANSPORT OF FLUIDS TO EXISTING HOST PLATFORMS • HSE BENEFITS 22 February, 2013 Presentation title 6
MAIN CAUSES OF RESTRICTIONS TO PRODUCTION & TOTAL RECOVERY • Low reservoir pressure/aging field • Tight, fragmented resevoirs,poor Permeability /PI • Deep reservoirs/deep wells-long flow path • Low GOR /liquid loading • Rising water cut • Long distance transport (Satellites) • High density and viscosity oil • Poor well inflow characteristics • Topside Process system pressure requirements • Hostile environments ,e.g. Arctic A boosting system is therefore needed to maintain or increase production and total recovery
HOW TO MAINTAIN PRODUCTION AND IMPROVE RECOVERY Primary recovery Rate of Recovery (RR) Less than 35% Artificial Surface boosting Natural flow lift systems RR 30%-50% Secondary recovery SS Production/boosting Pressure Maintenance WATER FLOODING IOR Tertiary recovery RR 50% to 80% Others Steam, Hot water, Chemical Gas injection combustion EOR CO2,N2,etc. Microbial, Acoustic, Alkali,Surfactant, Thermal Electromagnetic Polymer
SOLUTIONS TO MAINTAIN OR BOOST PRODUCTION AND TOTAL RECOVERY • MAINTAIN RESERVOIR PRESSURE. E.G. WATER INJECTION • IOR and EOR TECHNIQUES • ENHANCE INFLOW CONDITIONS E.G. ACIDIZE/FRACKING. • DOWNHOLE ARTIFICIAL LIFT;GAS LIFT,ESPS, FOAM INJECTION ETC. PROBLEMS OF HORIZONTAL WELLS • SUBSEA PRODUCTION &BOOSTING-DEEP OR HOSTILE WATERS • EXTENDED REACH HORIZONTAL WELLS • LOWER FLOWING WELLHEAD PRESSURE (FWHP)-VARIOUS METHODS ,INCLUDING SURFACE JET PUMP (SJP)SYSTEMS SOLUTIONS DICTATED BY ECONOMICS ,RISKS AND FIELD/PLATFORM CONSTRAINTS. Combined solutions are often needed 22 February, 2013 Presentation title 9
PRODUCTION FLOW PATH MANIFOLD PIPELINE WELLHEAD RESERVOIR WELL BORE - PRESSURE LOSS - CONNECTORS IOR/EOR - ARTIFICIAL - XMAS TREE - FLOW REGIME/SLUGS -VALVES 4D- LIFT -INJECTION -TEMPERATURE -INSTRUMENTS SESMICS - EXTENDED SYSTEM -CORROSION -METERING REACH -EROSION -FRAME - FLOW -NASTIES;WAX,SCALE.. ENHANCING ,ETC SOLUTIONS -PIPELINE INTEGRITY TOPSIDE SS SLUG EXPORT PIPELINE RISER PROCESS BOOSTING CATCHER -PUMPING - MPH PUMPS - SLUGGING AS - PROCESS - SLUG CATCHER COMP`N -SS SEP`N+ -DP ABOVE -BOOSTING -L.PUMPING PUMP. -INTEGRITY SYSTEMS -GAS COMPRESSION 22 February, 2013 Presentation title 10
COMMON SS COMPONENTS/ISSUES • MODULARISATION • CONNECTORS • INSTRUMENTS • POWER SUPPLY (ELECTRIC,EH,HYDRAULIC) • DATA TRANSMISSION • ACCESS • IMR/SERVICE VESSEL REQUIREMENTS 22 February, 2013 Presentation title 11
MODULARISATION February 13 Presentation title
SUBSEA TEMPLATE AND MOON POOL MODULES INSTALLATION AND RETRIEVAL 22 February, 2013 Presentation title 13
MULTI-BORE SS CONNECTOR KEY FEATURES; • MULTIBORE • SEALS • ACTUATORS • ELECTRIC/HYDRAULIC POWER • SHOULD BE RETRIEVABLE • SEALS IN RETRIEVABLE SS MULTIBORE CONNECTOR PART • PURGING FEATURE • HORIZONTAL OR VERTICAL 22 February, 2013 Presentation title 14
EOR OPTIONS TO ENHANCE RECOVERY STATE OF ART 22 February, 2013 Presentation title 15
WELL BORE FLOW ASSURANCE • MINIMISE PRESSURE LOSS • FLOW REGIME /PREVENT LIQUID LOADING • PROBLEM OF HORIZONTAL WELLS • ARTIFICIAL LIFT SOLUTIONS ( ESP,JET PUMP,GAS LIFT,FOAM, ETC.) • VELOCITY STRING (GAS APPLICATION) • CHEMICALS-SALINITY REDUCING,VISCOSITY REDUCING ETC. • REDUCE WELLHEAD PRESSURE 22 February, 2013 Presentation title 16
WELLBORE, FLOW REGIME MAP • ARTIFICIAL LIFT METHODS • GAS LIFT Superficial Liquid Velocity • ESPs Slug • CHEMICAL (m/s) Annular Mist INJECTION (FOAM ) Bubble • VELOCITY STRING (GAS ) Froth • JET PUMPS SUPERFICIAL GAS VELOCITY (m/s) 22 February, 2013 Presentation title 17
22 February, 2013 Presentation title 18
SUBSEA LIUHUA FIELD ,S-CHINA SEA 25 SS ESPs IN OPERATION FOR NINE YEARS 22 February, 2013 Presentation title 19
FLOW THROUGH SS PIPELINES • PRESSURE LOSS (H.HEAD+FRICTION) • FLOW REGIME,SLUGGING,LIQUID BUILD-UP • TEMPERATURE/HYDRATES • NASTIES; SAND,SCALE,WAX,ASPHALTENE ETC • CHEMICALS,INHIBITORS,DRA, ETC. • PIGGING REQUIREMENTS • CORROSION/EROSION • PIPELINE INTEGRITY • METERING 22 February, 2013 Presentation title 20
PRESSURE&TEMPERATURE PROFILE FOR GAS LINE 22 February, 2013 Presentation title 21
EFFECT OF TURN DOWN IN GAS RATE 22 February, 2013 Presentation title 22
Chevron, USA (GOM) Solution ; HP gas from the existing compressor on recycle used to power the jet pump (Php/Plp=4.9.Qhp/Qlp= 2.11,Pd/Plp=2 ) Benefits Lowered arrival pressure at the platform by 200 psi enabling loaded wells to produce consistently • Higher gas velocities, lowered liquids accumulated in the pipeline, causing a further 140psi drop at the wellhead 40MMSCFD 200 psig Export Sales 400 psig • Production increased by 24% due to wellhead pressure reduction and lower pipeline loss. 1250 psig process Ejector • 2.5 Bscf of otherwise lost reserves recovered. Recycle gas 7.4 MMSCFD GEMINI 850 psig Sub sea manifold 22 February, 2013 Presentation title 23
PRESSURE LOSS DISTRIBUTION-SS GAS PRODUCTION 100 90 80 % OF TOTAL PRESSURE DROP 70 60 ELEVATION 50 FRICTION 40 30 20 10 0 0 10 20 30 40 50 60 GAS FLOWRATE (MMSCFD) WATER DEPTH 2,000m 22 February, 2013 Presentation title 24
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TYPICAL PRESSURE LOSS ALONG PIPELINES 22 February, 2013 Presentation title 26
HIGH PRESSURE DROP DEMANDS SS BOOSTING SYSTEMS TO IMPROVE PRODUCTION &RECOVERY 22 February, 2013 Presentation title 27
TYPICAL HYDRATE FORMATION CURVE 250 HYDRATE FORMING 200 REGION PRSSURE (BAR) 150 100 STABLE NON FORMING 50 REGION 0 0 5 10 15 20 25 TEMPERATURE ( ⁰C)
IF YOU CANT MEASURE, YOU CANT CURE OR IMPROVE • THE NEED FOR DATA COLLECTION, DOWNHOLE,INDIVIDUAL WELLS, SUBSEA LINE AND SUBSEA EQUIPMENT • RELIABLE INSTRUMENTS ARE NEEDED • RELIABLE DATA TRANSMISSION IS NEEDED • RELIABLE AND EFFICIENT DATA MANAGEMENT SYSTEM IS NEEDED 22 February, 2013 Presentation title 29
SUBSEA METERING/WELL TESTING • KNOWLEDGE OF PRODUCTION RATE OF G/W/OIL IS IMPORTANT FOR MANAGEMENT OF PRODUCTION • METERING PRODUCTION FROM SATELLITE WELLS IS ALSO NEEDED • NO RELIABLE SS MULTIPHASE METERING SYSTEM EXISTS, BUT SOME HAVE BEEN USED • FOR TESTING SS WELLS A TEST MANIFOLD + METRING SYSTEM IS NEEDED • ACCURACY OF METRING MAY HAVE TO BE COMPROMISED FOR THE TIME BEING 22 February, 2013 Presentation title 30
CHEMICAL INJECTION A variety of chemicals are introduced at wellhead to achieve flow assurance, including; • HYDRATE INHIBITOR • CORROSION INHIBITOR • DRAG REDUCING AGENT There are also chemicals injected downhole; • CORROSION INHIBITOR/SCALE INHIBITOR • WATER TO REDUCE SALINTY OF PRODUCED WATER • FOAMING AGENT/OTHER COCKTAILS&SOLVENTS 22 February, 2013 Presentation title 31
PIGGING REQUIREMENTS • MOST PIPELINES REQUIRE PIGGING TO CLEAN THE LINE OR TO INSPECT THE LINE INTERNALLY • SS PIG LAUNCHER AND RECEIVER ARE NEEDED • THERE IS A REASONABLE TRACK RECORD • INCREASE IN OPEX & CAPEX IF ALL PIGGING SYSTEM IS SUBSEA ; • THERE IS EXPERIENCE IN SS PIGGING 22 February, 2013 Presentation title 32
RISER GENERATED PROBLEMS • SLUG GENERATION –EFFECT OF RISER PROFILE • PRESSURE LOSS/ FLOW SURGE/SLUGGING • GAS LIFTING AT BASE OF RISER • SLUG CATCHER AT THE BASE OF RISER • RISER STRUCTURAL INTEGRITY-SLUG EFFECT • NEW TECHNIQUE TO MINIMISE RISER GENERATED SLUGGING 22 February, 2013 Presentation title 33
1984 22 February, 2013 Presentation title 34
General Slug Control Structure Cranfield university Actuator Selection PC • Measurement candidates: Measurement – Different pressures Selection FT DT FT – Different flow rates PT PT – Density LT – Levels • Alternative actuators FT LC – Riser outlet choke – Gas outlet choke – Gas injection PT
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