Offshore Structure

TRAINING MODULE FOR NEW JOINEES.

ON

OFFSHORE STRUCTURES.

GENERAL CONFIGURATION

REV.0

PREPARED BY

CDR(Retd) U.C.RATH

ASSISTED

BY

Mr A KUMARSWAMY

Mr S PANIGRAHI

Mr S MATHIVANAN

OFFSHORE STRUCTUREINTRODUCTION

OFFSHORE PLATFORM IS DESIGNED, CONSTRUCTED AND INSTALLED AT SITE TO FULLFIL CERTAIN ROLE AS ENVISAGED BY THE CUSTOMER/OWNER OF THE PLATFORM.

OFFSHORE STRUCTURES USED FOR OIL AND GAS EXTRACTION HAS THE COMMON FUNCTION OF PROVIDING A SAFE, DRY WORKING ENVIROVMENT FOR THE EQUPIPMENT AND PERSONNEL WHO OPERATES THE PLATFORM.

THE TOTAL PROCESS FROM TENDERING TILL COMMISIONING IS ACOMPLISHED BY PARTICIPATION OF MULTIPLE AGENCIES SUCH AS CUSTOMER ITSELF, YARD, DESIGNER, VENDORS, SUBCONTRACTORS, GOVERNMENT AND OTHER AUTHORITIES, INSPECTION AND CERTIFICATION AUTHORITIES, AND MAY BE FEW MORE.

THE TASK IS COMPLICATED, MASSIVE, COSTLY, TECHNOLOGY ORIENTED, TIME BOUND AND RISKY.

HENCE NEEDS TO BE EXECUTED AS A PROJECT BY QUALIFIED AND EXPERIENCED AGENCIES/PERSONNEL WITH METICULOUS PLANNING, EFFECTIVE COORDINATION AND RIGOUROUS MONITORING.MONITORING OF THE CRITICAL PATH OF THE SCHEDULE IS IMPORTANT.

STAGES OF THE PROJECT.

LIKE FOR ANY OTHER PROJECT, ALSO IN THIS CASE, THE FOLLOWING ACTIVITIES ARE TO BE CARRIED OUT SEQUENTIALLY/PARALLELY/SIMULTANEOUSLY AS PER PLANNING OF THE PROJECT FROM ITS INCEPTION TO COMPLETION.

DEFINE ROLE

PRE ENGINEERING SURVEY.

STATEMENT OF REQUIREMENT TO MEET THE ROLE

DESIGN AND MATERIAL PROCUREMENT

DESIGN, PRODUCTION, QC &I, MATERIAL PROCUREMENT

YARD TESTS AND TRIALS

LOAD OUT AND TRANSPORTATION TO SITE

INSTALLATION, QC & I

PRE COMMISSIONING TESTS AND TRIALS

COMMISSIONING

HANDING OVER

ROLE

EXTRACT CRUDE OIL MIX FROM SEA BED BY DRILLING OPERATION

SEPARATION OF CRUDE OIL, GAS AND WATER AT OFFSHORE

TRANSPORT CRUDE OIL TO SHORE REFINERIES BY PIPELINE/ TANKERS

TRANSPORT GAS TO SHORE

TREATMENT AND DISPOSAL OF WATER AND WASTE GAS

SPECIAL SERVICES PLATFORM

PRE ENINEERING SURVEY

SEABED STUDY.

OCEANNOGRAPHIC STUDY.

REQUIREMENT TO MEET THE ROLE LOCATION AT SEA.NEED TO HAVE A PLATFORM/PLATFORMS AT

SPECIFIED LOCATIONS AT SEA

CHOOSE THE TYPE OF JACKET.

OPERATION ROUND THE YEAR

PLATFORM TO ACCOMMODATE EQUIPMENT AND SYSTEMS

REMOTE/MANUAL/EMERGENCY OPERATION AS PER REQUIREMENT

PERIODIC TESTING OF CRUDE OIL MIX EXTRACTED FROM OIL WELL.

ENERGY TO RUN EQUIPMENT, LIGHTING, CONTROL SYSTEMS

LOADING AND UNLOADING MATERIAL

LIVING SPACE

APPROACH TO PLATFORM

LIFE & MAINTENANCE

ENVIRONMENTAL DATA TO KNOW THE MAGNITUDE, DIRECTION AND POINT OF APPLICAION OF FORCES

TECHNICAL SPECIFICATIONS OF EQUIPMENT

REGULATIONS

CODES

MATERIAL SUPPLY

REDUNDANCY

RELIABILITY

INTERLOCK

NOISE AND VIBRATION

PREVENTION OF MARINE GROWTH

ANY OTHER REQUIREMENTS

COMMUNICATION

RESCUE

SAFETY

DESIGN, TENDERING AND MATERIAL PROCUREMENT

CONCEPTUAL (FEED) DESIGN

TENDERING AND FINALISATION OF CONTRACTOR

MATERIAL PROCUREMENT

DETAIL ENGINEERING

MATERIAL PROCUREMENT

FABRICATION/SHOP ENGINEERING

MATERIAL PROCUREMENT

DETAIL DESIGN, PRODUCTION, QC &I, MATERIAL PROCUREMENT

CONCURRENT ACTIVITIES 

MONITORING OF CRITICAL TARGETS

YARD TESTS AND TRIALS

MECHANICAL CLEARANCE

LEAK TEST 

PRESSURE TEST

WEIGHING

LOAD OUT AND TRANSPORTATION TO SITE

LOAD OUT ANALYSIS 

LOAD OUT ROUTE 

BARGE SURVEY 

JETTY SURVEY 

BARGE FLOATION AND STABILITY AT JETTY 

BARGE FLOATION AND STABILITY AT SEA FOR A GIVEN SEA STATE

INSTALLATION, QC & I

LIFT THE JACKET HORIZONTALLY BY HOLDING AT LIFTING TRUNION

JACKET POSITIONED ON THE SEA SURFACE SUPPORTED BYCRANE & BUOYANCY TANK. 

JACKET TILTED FROM HORIZONTAL TO VERTICAL POSITION BY FLODDING THROUGH THE FLODDING LINES.

JACKET IS SUPPORTED IN ITS VERTICAL POSITION AT THE UPENDING PAD EYE  BY THE CRANE.

LOWER & PLACE THE JACKET AT THE SPECIFIED LOCATION AT THE SEA BED.

FIX THE JACKET BY PILING.  POSITION AND WELD THE TRANSITION PIECE. LIFT THE TOP SIDE, ALIGN, POSITION IT ON THE JACKET, AND

COMPLETE THE OFFSHORE WELDING BETWEEN THE JACKET AND THE TOP SIDE

PRE COMMISSIONING TESTS AND TRIALS

PERFORMANCE OF EACH SYSTEM, EQUIPMENT AND INSTRUMENT IS PROVED TO MEET THE DESIGN PARAMETERS/SPECIFICATIONS

COMMISSIONING

HANDING OVER

DESIGN TO MEET THE FUNCTIONAL REQUIREMENT/ROLE

FUNCTION STRUCTURE/SYSTEM• TO HOUSE EQUIPMENT/SYSTEMS AND CREW TOP SIDE • TO SUPPORT THE TOP SIDE JACKET • SUPPORT DURING CONSTRUCTION LEG POT &  & TRANSPORTATION LOAD OUT BEAMS

• INSTALLATION FLEXIBILITY TRANSITION PIECE • SECURING JACKET AT SITE PILES 

APPROACH TO PLATFORM BY  SEA BOAT LANDING STRUCTURE AIR HELI DECK 

LOADING/ UNLODING ITEMS CRANE 

GUIDED ACCESS FOR DRILLING RIG CONDUCTOR PIPES & OIL EXTRACTION PIPES  

ROUTING OF CONDUCTOR PIPES CONDUCTOR GUIDES

ACCESS WITHIN PLATFORM LADDERS / LIFTS 

ENERGY SOLAR PANEL DIESEL OR GAS GENERATORS 

TRANSPORTING OIL FROM OIL WELL RISER CLAMPS & TO PROCESS PLATFORM HOLD RISER LINES

LIFTING OF JACKET DURING INSTALLATION LIFTING TRUNION &

APPENDING PAD EYE TILTING OF JACKET DURING INSTALLATION. FLOODING LINE.

FILLING THE GAP BETWEEN SKIRT LEG & PILE. GROUT LINE.  

INSTALLATION OF DECK LIFTING PAD EYE 

DISPOSAL OF VENT GAS AT HEIGHT VENT BOOM 

PROTECTION FROM CORROSION ANODES/PAINT

PROTECTION AGAINST RUBBING RUB STRIP 

GUIDED PATH FOR PILES PILE GUIDE 

STABILITY AND SUPPORT DURING INSTALLATION MUD MAT 

  LIVING SPACE ACCOMMODATION (TRANSIT/PMT) ALLEY/PANTRY/ DINING RECREATION SICK BAY

CONCEPTUALISATION AND CONFIGURATION OF OFFSHORE PLATFORM

RESOLUTION OF CONFLICTING COMPLICATED ISSUES

LEADING  

TO

BEST POSSIBLE DESIGN

OR

OPTIMUM DESIGN 

OPTIMISATION OF COST 

WITHIN THE BOUNDARY CONDITIONS (CUSTOMERS’ REQUIREMENTS/DESIGN CONSTAINTS)

CRITICAL DESIGN TASKS

LAYOUT

MINIMUM VOLUME/AREA 

FUNCTIONAL REQUIREMENT 

EASY MAINTAINABILITY 

EASY TO OPERATE 

EASY ACCESSABILITY 

FEELING OF SPACE 

RULING OUT PHYSICAL, ELECTROMAGNETIC AND FUNCTIONAL INTERFERENCE 

HABITABILITY

STRUCTURAL CONFIGURATION

ADEQUATE STIFFENING TO WITHSTAND STATIC AS WELL AS DYNAMIC FORCES AND MOMENTS 

STRENGTH & STABILITY 

AVAILABILITY OF MATERIAL 

STRUCTURAL SIMPLICITY 

EASY FABRICATION 

CORROSION ALLOWANCE 

FACTOR OF SAFETY

ARCHITECTURAL CONFIGURATION 

TRANSPORTATION AND INSTALLATION FEASIBILITY 

REGULATIONS AND CODES 

PROCUREMENT CONTSTRAINTS 

DATA CONSTRAINT 

ADHERANCE TO ALL REQUIREMENTS SPECIFIED BY CUSTOMER 

COST

TYPES OF TOP SIDES

MANNED/UNMANNED 

WELL/PROCESS 

WI/GI

CONCRETE 

TENSION LEG 

GUYED LEG

STEEL

TYPES OF JACKETS

TYPES OF OFFSHORE PLATFORMS

DIFFERENT COMBINATIONS OF TOPSIDES AND JACKETS WOULD LEAD TO DIFFERENT TYPES OF OFFSHOE

STRUCTURES HAVING DIFFERENT ROLES

TYPICAL OFFSHORE STRUCTURE

TOPSIDE SYSTEMS

ON

BOARD A TYPICAL UNMANNED WELL HEAD PLATFORM

TOPSIDE SYSTEMS

PROCESS LINE.

INSTRUMENT GAS.

UTILITY GAS.

LIFT GAS.

CHEMICAL INJECTION.

WATER INJECTION.

VENT GAS.

FIRE WATER.

DRAIN HYDROCARBON.

DRAIN WATER.

PROCESS LINE.FUNCTION OF PROCESS LINE IN A WELL HEAD PLATFORM IS TO TRANSPORT OIL FROM OIL WELL TO THE PROCESS PLATFORM.THIS CONSISTS OF PIPE LINES,MANIFOLDS,VALVES,EQUIPMENT & ELECTRICAL & INSTRUMENTATION DEVICES ETC.

CRISTIMAS TREE

PRODUCTION MANIFOLD.

TEST SEPERATOR.

PIPE SEPERATOR.

HEAT EXCHANGER

LAUNCHER.

FOLLOWING ARE THE MAJOR COMPONENTS OF PROCESS LINE:-

CRISTMAS TREE:-

THIS CONSISTS OF CHOKE VALVES MEANT FOR REDUCING/REGULATING THE FLOW/PRECISE OF THE OIL RECEIVED FROM OIL WELL.

PRODUCTION MANIFOLD:-

HIGH INTEGRITY PRESSURE PRODUCTION SYSTEM

THIS CONSISTS OF VALVES FOR MONITORING THE OIL FLOW.THE GAS FLOWS FROM PRODUCTION MANIFOLD TO THE SEPERATORS.HIPPS PROTECTS DECK EQUIPMENT AGAINST RAISED PRESSURE OF THE FUEL BY CLOSING DOWN ITSELF.

TEST SEPERATOR:-

IT RECEIVES OIL MIXTURE FROM THE MANIFOLD FOR PURPOSE OF ANALYSIS OF THE SAMPLE i.e DETERMINATION OF p.c OF OIL,WATER & GAS IN THE CRUDE MIXTURE RECEIVED FROM OIL.THIS ANALYSIS IS CARRIED OUT PERIODICALLY OR ON A REQUIRED BARS.DECK IS USED FOR PROCESSING THE CRUDE OIL MIXTURE IN THE PROCESS PLATFORM.

PIPE SEPERATOR:-

SEPERATES GAS FROM CRUDE OIL MIXTURE AND PROVIDES GAS FOR VARIOUS SERVICES ON BOARD THE WELL HEAD PLATFORM.

HEAT EXCHANGER:-

THIS IS USED FOR HEATING THE GAS BEFORE SENDING IT TO THE SERVICES SUCH AS INSTRUMENTATION ETC. THIS IS INTEGRATED WITH THE MAIN PROCESS LINE.HEAT EXCHANGE TAKES PLACE BETWEEN GAS & THE OIL MIXTURE PASSING THROUGH THE PIPE LINE.

LAUNCHER:-

THIS IS INTEGRATED WITH THE MAIN FOR LAMINATING THE SCRABER IN TO THE PROCESS LINE.THIS IS IS USED FOR PERIODICALLY REMOVING CORROSSION IN THE PIPE LINE.

AUXILLARY SYSTEMS:-

C I SYSTEM :- INSTALLED TO INJECT CHEMICAL IN THE CRUDE OIL MIXTURE PASSING THROUGH THE PROCESS LINE TO PREVENT CORROSION INTERNALLY IN THE PIPELINE.

W I SYSTEM:- INSTALLED TO INJECT WATER INTO THE OIL WELL WHEN NECESSARY. THE SYSTEM HELPS IN INJECTING WATER INTO THE OIL WELL TO INCREASE PRESSURE IN THE WELL.OIL FLOW TO THE PRODUCTION MANIFOLD IS RESTORED UNDER WATER PRESSURE INJECTED THROUGH W I SYSTEM. THIS IS NECESSARY WHEN THE OIL FROM

OIL WELL CEASE TO RISE AFTER LONG USE DUE TO REDUCTION IN PRESSURE.

LIFT GAS:- INSTALLED TO PASS LIFT GAS UNDER PRESSURE INTO THE OIL WELL TO RESTORE SUPPLY OF CRUDE FROM OIL WELL TO THE MANIFOLD.THIS MAY BE USED IN LIEU OF W I SYSTEM.WHEN THE OIL FROM OIL WELL CEASE TO RAISE AFTER LONG TIME DUE TO REDUCTION IN PRESSURE INSIDE THE OIL WELL.

CRUDE CONDENSATE DRUM:- CRUDE OL MIXTURE & WATER FROM DRAIN IS COLLECTED IN THIS DRUM.WATER SETTLED AT THE BOTTOM OF THIS TANK IS DISCHARGED TO THE SEA.THIS COMPONENT IS RELEASED THROUGH VENT BOOM.OIL IS PUMPED INTO THE PROCESS LINE USING LIFT GAS.

TYPICAL SCHEMATIC OF PROCESS LINE.

SCHEMETIC OF INSTRUMENT/UTILITY GAS SYSTEM

SCHEMATIC OF LIFT GAS SYSTEM

SCHEMATIC OF C I SYSTEM

SCHEMATIC OF W I SYSTEM

SCHEMATIC OF VENT SYSTEM

DIESEL IS REQUIRED AS FUEL FOR THE CRANE, THE BOATS AND

THE D.G.

DIESEL TANK IS PROVIDED FOR STORAGE OF DIESEL.

PROVISION TO RECEIVE STORE & DISTRIBUTE FROM OTHER

PLATFORM FOR UTILITY WATER & FIRE WATER.WATER TANK

MAY BE PROVIDED FOR STORAGE.

SOLAR BATTERIES PROVIDED FOR ILLUMINATION & NAVIGATIONAL LIGHTS.

D.G MAY BE PROVIDED FOR GENERATION OF POWER FOR OCCASIONAL OR LIMITED USE.