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Gas Plant Diversity. Jon Lewis, Global Director, Gas Processing, WorleyParsons. Presentation Outline. Company Introduction Natural Gas Terminology Basic Process Requirements Thermodynamics Processing Options Multiple Field Processing Gas Plant Examples A new Israeli Gas Plant?
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Gas Plant Diversity Jon Lewis, Global Director, Gas Processing, WorleyParsons
Presentation Outline • Company Introduction • Natural Gas Terminology • Basic Process Requirements • Thermodynamics • Processing Options • Multiple Field Processing • Gas Plant Examples • A new Israeli Gas Plant? • Project Drivers and Decision Criteria • Summary
Global Expertise of WorleyParsons With nearly 39,800 people in 165 offices throughout 43 countries, we provide our customers with a unique combination of extensive global resources, world-recognized technical expertise and deep local knowledge. 166 43 37,500
Responding to our customers’ changing needs • A single point of contact • Consolidated into three sectors WorleyParsons services three Customer Sector Groups
Basic Process Requirements Interdependence Extent Impurities Processing Hydrocarbon Processing
Thermodynamics – The Basics The secret to all gas plant designs is the optimum production and management of… Low temperatures! • Isobaric – constant pressure • Isenthalpic – constant enthalpy • Isentropic – constant entropy
Phase Envelope Cricondenbar Cricondentherm
Phase Envelope – The Basics Feed Point Feed Point
Phase Envelope – The Basics Feed Point Feed Point
Importance of Characterisation Composition
Typical Gas Plant Blocks • NGL Removal • Acid Gas Removal • CombinationProcesses • Dehydration
Technology Options • Acid Gas Removal Liquid Absorption Solid Adsorption (Mole Sieves) Membranes Solid Scavenger Liquid Scavenger
Acid Gas Removal • Acid Gas Removal Technology Options Regenerable Solid Adsorption(Mole Sieve, Silica Gel) Non Regenerable Adsorption Liquid Absorption (Glycol) Dehydration by Cooling • Dehydration
Acid Gas Removal Technology Options • NGL Removal Mechanical Refrigeration (isobaric) Joule-Thomson Expansion (isenthalpic) Turbo-Expansion (isentropic) Solid bed – Short Cycle Silica Gel Lean Oil Absorption (historic) Novel Technologies • Dehydration
Acid Gas Removal Technology Options • NGL Removal Mole Sieve - Dehydration/Mercaptan/COS/Mercury Removal Acid Gas Removal/Gas Dewpointing Dehydration/BTEX removal (TEG) NGL and Mercaptan Removal Condensate Removal and Dehydration (Solid Bed – Short Cycle (Silica gel) • Combination Processes • Dehydration
Technology Options • NGL Removal • Acid Gas Removal Mechanical Refrigeration (isobaric) Joule-Thomson Expansion (isenthalpic) Turbo-Expansion (isentropic) Solid bed – Short Cycle Silica Gel Lean Oil Absorption (historic) Novel Technologies Liquid Absorption Solid Adsorption (Mole Sieves) Membranes Solid Scavenger Liquid Scavenger Mole Sieve - Dehydration/Mercaptan/COS/Mercury Removal Acid Gas Removal/Gas Dewpointing Dehydration/BTEX removal (TEG) NGL and Mercaptan Removal Condensate Removal and Dehydration (Solid Bed – Short Cycle (Silica gel) Regenerable Solid Adsorption(Mole Sieve, Silica Gel) Non Regenerable Adsorption Liquid Absorption (Glycol) Dehydration by Cooling • Combination Processes • Dehydration
Then Reality Sets In And just in case you thought it was that simple, what about … Declining reservoir pressure Gradual souring Uncertainty of composition New product markets Accommodating new reservoir fluids
Multiple Field Processing UK – Central Area Transmission System (CATS)
Gas Plant Diversity Gas plants are different because: They have different feed and product slates They process gas at the conditions it arrives Feed and product slates change over time Arrival conditions change over time Plant modifications are common
Example Gas Plants San Juan Gas Plant 64% of cooling requirements • 420 mmscfd • 59 barg Outlets for ethane are commercially driven • DEA • 45 barg • 30°C • 5% CO2 Dehydration by molecular sieve (-100°C dewpoint) • Liquids Production • 42,000 bpd • (6,700m³/d) • 500 mmscfd • Sweet gas • 98% ethane recovery 28 barg 59 barg 2 identical 50% trains Turbo expansion (to 24 barg) and demethaniser cold reflux 24 barg Source: A.J. Kidnay, W. R. Parrish and D. G. McCartney, “Fundamentals of Natural Gas Processing”, 2nd ed. 2011, CRC
Example Gas Plants Whitney Canyon Gas Plant • 99% sulphur recovery • 1,220 tpd • rail cars • DEA (lean and semi-lean) • 69 barg • 35°C CO2 • 4ppm H2S • CO2 to prevent downstream freezing • 270 mmscfd • sour gas (1-19% H2S) • NGL recovery • Sulphur recovery • Large feed gas variability 70 barg • Flash gas/combined with stabiliser off gas (10ppm) for DEA treating at 17 barg to 4ppm. • Sweet gas recycled to inlet compression 17 barg • Liquids Production • 13,000 bpd NGL • (2,100 m³/d) • 6,000 bpd condensate (970 m³/d) • TEG-bulk water removal • molecular sieve – 0.1ppm for cryogenic NGL recovery • molecular sieve not used when NGL recovery not required • 88% ethane recovery, or ethane rejection (97% propane recovery) • Turbo expansion Stabilisation and NGL treating, 10ppm, H2S Source: A.J. Kidnay, W. R. Parrish and D. G. McCartney, “Fundamentals of Natural Gas Processing”, 2nd ed. 2011, CRC
Example Gas Plants Hannibal Gas Plant 83 barg • 10 tpd, liquid redox plant • Claus Plant not justified • Now replaced with sulphuric and acid unit • Heat Exchange • Joule –Thomson expansion • Cryogenic distillation • N2 vented • 265 mmscfd • Sour Gas • Sulphur recovery • Nitrogen rejection • No NGL recovery 6.5 % N2 • Activated MDEA • 200ppm CO2 • some BTEX removal 180 mmscfd • TEG – bulk water & BTEX removal, then molecular sieve • BTEX removal to prevent freezing in NRU • BTEX routed to condensate storage • CO2, water and BTEX removal • Prevent freezing/plugging downstream Debutaniser Source: A.J. Kidnay, W. R. Parrish and D. G. McCartney, “Fundamentals of Natural Gas Processing”, 2nd ed. 2011, CRC
Example Gas Plants Idku Gas Plant Three pipelines Three Slug Catchers 5 x trains 2 x trains 26 barg West Delta Deep Marine • Multiple Phases • Phase 9b under development 55 barg • Plant modifications include: • Booster compression • Main compression • Additional TSA bed Short cycle (TSA) 2 x trains, 4 beds each 2,000 mmscfd nominal capacity 4 x trains Hydrate control by MEG injection. (MEG recovery and regeneration not shown)
Example Gas Plants CATS Gas Plant One train – Joule Thomson One train – Turbo expansion • Dense Phase reception • Dew Point Plant • Minimum liquids recovery • No CO2 removal • Carbon steel 300 kg/d H2S 2 x trains of 600 mmscfd each Nitrogen injection for HHV control TEG
Example Gas Plants Point of Ayr Gas Plant 20 tpd Claus + TGTU 2 x 50% train • 300 mmscfd • H2S 1600ppm • Mercaptans 160 ppm (+ misc.S) 50 barg 9 – 16°C Mercaptan concern • Adjacent holiday resort • Water cooled • No air coolers • Amine • Originally hybrid • Changed to chemical Propane Methanol used for hydrate inhibition Reinjected offshore methanol added to line, regenerated offshore
Example Gas Plants Langeled Gas Plant Joule-Thomson expansion Glycol/Water PCHE Cyclonic 99.8% Availability 4 x 33% trains 4 x 33% metering runs 4 x 33% glycol/water pumps 4 x 33% glycol/water heaters 2 x 70% glycol/water expansion drums 3 x 100% air compressors 2 x 100% air driers 2 x 100% flare KO drums Emergency Generators – entire plant demand 2 x 100% UPS (process/systems) 2 x 100% UPS (telecoms) • 2,600 mmscfd (max) • 73 – 140 barg • 0.4 to - 4°C • (excluding future compression case) • Treated gas • No NGL recovery • No sulphur recovery A plant that does nothing! 60,000m²
Project Drivers and Decision Criteria Project Drivers Minimum CAPEX to first gas Preserve schedule Manage commercial exposure Maximise recovery (over life of field) Maximum flexibility (around evolving data) Max ramp-up / shortest plateau Minimum lifecycle / maximum value Accommodate future development Proven Conventional Technology Langeled Gas Plant
Project Drivers and Decision Criteria Decision Criteria CAPEX OPEX Inherently Safer Design (ISD) Flexibility Operability
Summary Natural Gas Terminology Basic Process Requirements Thermodynamics Processing Options Multiple Field Processing Gas Plant diversity Gas Plant Examples A new Israeli Gas Plant? Project Drivers and Decision Criteria Sales gas, LNG, LPG, NGL, condensate Treat to meet export specifications for gas and recovered liquids, and/or facilitate downstream processing Integration of contaminant removal and hydrocarbon processing Isobaric, isenthalpic and isentropic pathways Acid gas removal, dehydration, NGL removal Multiple options within each Combination processes Why gas plants are different Diverse plants with different processing requirements CAPEX Schedule Maximise recovery, use of facility Proven technology Inherent safety