Design Theories of Ship and Offshore Plant

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1 Lecture Note of Design Theories of Ship and Offshore Plant Design Theories of Ship and Offshore Plant Part I. Ship Design Ch. 2 Introduction to Offshore Plant Design Fall 2015 Myung-Il Roh Department of Naval Architecture and Ocean Engineering Seoul National University 1 Contents Ch. 1 Introduction to Ship Design Ch. 2 Introduction to Offshore Plant Design Ch. 3 Hull Form Design Ch. 4 General Arrangement Design Ch. 5 Naval Architectural Calculation Ch. 6 Structural Design Ch. 7 Outfitting Design 2 1

2 Ch. 2 Introduction to Offshore Plant Design 3 Natural Gas (NG) Natural Gas Hydrocarbon gas mixture consisting primarily of methane (CH 4 ) Clean energy for preventing environmental pollution Used for all fields of home, commerce, transportation, industry, etc. Providing about ¼ of energy consumption of the world It will be continuously increased. Special Features Liquefied at -162 C under atmospheric pressure Liquefied Natural Gas () When liquefied, the volume becomes 1/600. Reason why we carry NG as 4 2

3 Worldwide Reserves of Natural Gas (2014) The reserves are not biased to the Middle East and are distributed worldwide, and the amount is very large. The development field moves from near sea to far sea. * Reference: 5 Offshore Plants for Oil and Gas Development ~150m (In general, about 50m) 100~200m 200~500m about 1,000m 6 3

4 Offshore Plant for the Development of Deep Sea - Production plant for separating the well stream into oil, gas, and water and then transferring them to onshore - Topsides for the production and Hull for the storage of oil and gas - Process and Utility for Topsides equipment and instruments - Oil FPSO / FPSO Topsides Hull 7 Components Distillation & Fractionation Refining Crude Oil C1:CH4 C2:CH3CH3 C3:CH3CH2CH3 C4:CH3(CH2)2CH3 C5:CH3(CH2)3CH3 C6:CH3(CH2)4CH3 Oil C7~ Gasoline C5~C10 Kerosene C10~C16 Light Oil C16~C20 Heavy Oil C20~C25 Petroleum Heavy Components Asphalt C25~C30 Refining Gas Refrigeration Dehydrated Gas Pitch C1(CH4) NGL C2 C3, C4 C5, C6 Light Components 8 4

5 Concept of FPSO(Floating Production, Storage, and Offloading Unit) Production of the by onshore facility Natural gas from the offshore production site is transported by the pipe line to the onshore plant where the NG is liquefied to the. The FPSO is a floating vessel having the production facility, liquefaction facility, storage tanks, offloading for the, and turret. Production of the by FPSO Far from the coast The natural gas is liquefied direct in the FPSO. Onshore plant and transport pipeline are not needed. 9 [Article] Shell decides to move forward with groundbreaking FPSO. The World s First FPSO Shell, the world s largest oil company, is now ready to start construction of what will be the world s first FPSO, in a ship yard, Samsung heavy industry, in South Korea. FPSO cools down the temperature of the natural gas (NG) from 27 C to -162 C to shrink in volume by 600 times. The liquefaction process for is most important of the FPSO. * MTPA: Million Ton Per Annual * Reference: [Article] Yonhapnews, Shell decides to move forward with groundbreaking floating,

6 Configuration of FPSO FPSO (Numbers under the parts mean the cost distribution) Hull 20% of FPSO Topsides 70% of FPSO Turret 10% of FPSO Process 70% of Topsides Utility 30% of Topsides Liquefaction process (Separating the gas components into the NGL and natural gas (NG) and liquefying NG) Separation process 20% of Process Pretreatment Process 10% of Process Fractionation Process 15% of Process Liquefaction Process 55% of Process (27% in FPSO) NG(Natural Gas): Main component is methane(ch4). (Liquefied Petroleum Gas): Main components are propane(c3h8) and butane(c4h10). NGL(Natural Gas Liquids): Main components are ethane(c2h6), propane(c3h8) and butane(c4h10). It exists in the gas phase at 1 atm and 20 C. That is, NGL = + ethane(c2h6) : Main components are Pentane(C5H12) and Hexane(C6H14). It exists in the liquid phase at 1 atm and 20 C, so called oil. Fractionation process (Separating the NGL into the ethane, propane, and butane by distilling the NGL) Flare Tower For the compactness of the topsides process s, the pretreatment and liquefaction process s are arranged to cross each other. Utility (Gas turbine, etc.) Turret (mooring) Living Quarter Separation process (Separating water, condensate(liquid), and gas components (NGL+NG) using the difference of density) Pretreatment process (Removing the impurities such as CO 2, H 2S, water, and mercury) Production: (3.6MTPA) * MTPA: Million Ton Per Annual The liquefaction process for is most important. Reference) [Article] Yonhapnews, Shell decides to move forward with groundbreaking floating, Topsides Process System of FPSO (1/3) NG(Natural Gas): Main component is methane(ch4). (Liquefied Petroleum Gas): Main components are propane(c3h8) and butane(c4h10). NGL(Natural Gas Liquids): Main components are ethane(c2h6), propane(c3h8) and butane(c4h10). It exists in the gas phase at 1 atm and 20 C. That is, NGL = + ethane(c2h6) : Main components are Pentane(C5H12) and Hexane(C6H14). It exists in the liquid phase at 1 atm and 20 C, so 1. Separation process called oil Slug Catcher: Stabilizing slug flow from gas well : + NGL+ NG 1-2. Gas/Liquid Separator: Separating water, condensate (liquid), and gas components (NGL+NG) using the difference of density : (C5~C6) 1-3. Stabilizer: Since a part of gas components is not separated from the condensate completely in the : NGL + NG Gas/Liquid separator, separating the gas components from the condensate again, returning it to the gas flow and storing the left condensate in the condensate tank For the compactness of the topsides process s, the pretreatment process and liquefaction process are arranged to cross each other. Separation process Gas (500~1,000m) Gas (C1~C4) 2. Pretreatment process 1. Separation process 1-1. Slug Catcher 1-2. Gas/Liquid Separator C1~C6 Gas(C1~C4) 1-3. Stabilizer Pretreatment process (C5~C6) Tank 12 6

7 Topsides Process System of FPSO (2/3) 2. Pretreatment process 2-1. Acid Gas Removal System: Removing the acid gases (H 2 S, CO 2 ) which are corrosive to materials and toxic to human being 2-2. Dehydrate System: Removing the water which can forms the ice 2-3. Mercury Removal System: Removing the mercury which can damage the equipment and pipes 2-4. CO 2 Compression System: Venting or re-injecting the CO 2 removed from the gas into the CO 2 well *CO 2 well: To prevent the global warming, CO 2 is stored in the CO 2 well which is separated from the gas well. Liquefaction process NG(Natural Gas): Main component is methane(ch4). (Liquefied Petroleum Gas): Main components are propane(c3h8) and butane(c4h10). NGL(Natural Gas Liquids): Main components are ethane(c2h6), propane(c3h8) and butane(c4h10). It exists in the gas phase at 1 atm and 20 C. That is, NGL = + ethane(c2h6) : Main components are Pentane(C5H12) and Hexane(C6H14). It exists in the liquid phase at 1 atm and 20 C, so called oil. : + NGL+ NG : (C5~C6) : NGL + NG : CO 2 Separation process Gas (500~1,000m) 1. Separation process 2. Pretreatment process 2-1. Acid Gas Removal System CO 2 Pretreatment process CO CO 2 Compression System 2-2. Dehydrate System 2-3. Mercury Removal System 13 Topsides Process System of FPSO (3/3) NG(Natural Gas): Main component is methane(ch4). (Liquefied Petroleum Gas): Main components are propane(c3h8) and butane(c4h10). NGL(Natural Gas Liquids): Main components are ethane(c2h6), propane(c3h8) and butane(c4h10). It exists in the gas phase at 1 atm and 20 C. That is, NGL = + ethane(c2h6) : Main components are Pentane(C5H12) and 3. Fractionation process Hexane(C6H14). It exists in the liquid phase at 1 atm and 20 C, so called oil. 3.1 Ethane Distillation System: Separating NGL into the ethane and and using it as the refrigerant in the liquefaction. Some of is stored in the tank and the rest goes to Propane Distillation 3.2 Propane Distillation System: Separating into the propane (C3) and butane (C4) by distilling them which are used as : + NGL+ NG the refrigerant in the liquefaction 4. Liquefaction process Fractionation process : (C5~C6) 4-1. Natural Gas Liquids(NGL) Extraction System: Separating the NGL from the gas components : NGL + NG Natural gas composition: (NGL+NG) in the pretreatment process by precooling 4-2. Main Liquefaction System: Liquefying the natural gas by using the refrigerant : CO 2 Components Natural gas(mol %) 4-3. End Flash : Reducing the pressure of the ( C, 60 bar) to the atmospheric pressure (1~2 bar) : NGL (C2~C4) Nitrogen 6.0 Methane 83.2 Liquefaction process : (C3~C4) 3-1 Ethane 7.1 * C2 (ethane) tank, C3 (propane) tank, and C4 (butane) : (C1) tank: Storage tanks of the refrigerant used in the Propane 2.25 i-butane 0.40 liquefaction process n-butane 0.60 i-pentane 0.12 Separation process n-pentane 0.33 : NG composition for maximizing the amount of methane and satisfying the required the heating value of NG CO 2 Pretreatment process C2 Tanks Tank (C3~C4) C3 Tanks C4 Tanks (C2) (C3) (C4) Tank (C1) (500~1,000m) 3. Fractionation process 3.1 Ethane Distillation System 3.2 Propane Distillation System Gas 1. Separation process 2. Pretreatment process 4. Liquefaction process 4-1. Natural Gas Liquids(NGL) Extraction System 4-2. Main Liquefaction System 4-3. End Flash 14 7

8 Development Procedures of FPSO and Importance of FEED Development Procedures of FPSO Delivery Exploration & Feasibility Study Front-End Engineering Design Detailed Design Construction Start-up/ Commissioning Operations/ Maintenance Topsides FEED(Initial or Basic Design): Estimation of building cost, total weight, and layout of topsides by determining specifications of all s according to owner s requirements Our shipyards only take charge of after detailed design or production. In the case of topsides FEED, they are dependent on foreign design companies with about 10~20M$ per offshore plant. Topsides Hull 15 Procedures of Topsides Process FEED of Offshore Plant 1 Design Criteria Design Factor Database - Required Daily Consumption of Production - Components and Physical Data - Capacity - Environmental and Geographical Factor - Product Specification -HSE(Health, Safety, Environment) Req. < Offshore Process FEED Activities > 2 4 Process Simulation / Utility Consideration Determine physical, thermodynamic properties of each process stream = Heat & Material Balance PFD(Process Flow Diagram) UFD(Utility Flow Diagram) 3 Process & Utility Calculations Determine the size & capacity of equipments & instruments Make a drawing to show the safety & control logic of overall topside s and heat & material balance tables 5 PED(Process Equipment Datasheet) PID(Process Instrument Datasheet) UED(Utility Equipment Datasheet) UID(Utility Instrument Datasheet) 6 Preliminary P&ID (Pipe & Instrument Diagram) Make datasheets to show equipments and instruments data for performing procurement, construction, and operation of the topside s 16 8