enhancing safety during design stage

8/8/2019 Enhancing Safety During Design Stage

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2OFFSHORE DESIGN SECTION

ISO-9001:2000

Safety

General Definition :

Safety is the state of being

safe, the condition of being

protected against physical,

occupational events whichcould be considered non

desirable.

Safety of the personnel and of

the facility is one of the majorconcerns during the design of

the Offshore Platforms

.


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ISO-9001:2000

Safety aspects in

DESIGN

The safety aspects considered in the Design are:

a. Safety studies and risk assessment

b. General safety features Platforms &Pipelines.

c. Safety of personnel

Suitable functional specifications adopted based on:international codes , practices and recommendations /

suggestions of MDT


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ISO-9001:2000

A. Safety Studies and RiskAssessment

ALARP (as low as reasonable practicable) level is

achieved by

Field and layout review

Coarse quantified risk assessment

Hazard Identification (HAZID) Workshops

Hazard and Operability (HAZOP) studies.(Contd)


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ISO-9001:2000

A. Safety Studies & RiskAssessment (Contd)A

Safety Integrity Level (SIL) assessment

Consequence studiesEmergency system reviews

Escape and rescue analysis

Quantified Risk Assessment (QRA)


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ISO-9001:2000

B. General safety features on

UNMANNED PLATFORMS

Structural protection

Judicial layout of topside and field complex.

Pipeline and riser design.

Minimization of potential hydrocarbon release sources.Control of ignition sources.

Identification of fire zones.

Fire and gas detection systems.

(Contd)


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ISO-9001:2000

B.General safety features on

UNMANNED PLATFORMS Contd..

Emergency control systems.

Fire control and mitigation.

Explosion control and mitigationAlarms and communication systems

Escape and evacuation.

Protection against occupational hazards.

Material selection


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ISO-9001:2000

C. Safety of Personnel

Personnel safety & communication equipments :

Fire fighting

Rescue equipmentBreathing apparatus sets.

Stretchers.

Eye wash and safety showers.

First aid kit.

Paging system.


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ISO-9001:2000

Safety Aspects in Process Design

Fail safe design.

Two levels of safety (alarm & shutdown).

Safe disposal of relieved hydro carbon (automatic or

manual).

Efficient liquid hydrocarbon / chemical drainage.Fire water sprinkler system for cooling in case of fire.

Following

API RP 14C, 14G, 14F


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ISO-9001:2000

Safety aspects in Instrumentation

System Design

Gas detection system (hydrocarbon / H2S / Hydrogen )

Fire detection system ( SIL -3)Platform control system DCS- PP,SDP- WP

ESD & FSD

Suitable ingress protection provided- e.g.IP-52

Suitable explosion proof enclosures where reqd


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ISO-9001:2000

Safety Aspects in Electrical Design

API RP 500 followed for area classification, gas

groups, temperature classification.

Uninterrupted power supply for critical loads

Fault level calculations - Protective switch gear

Earthing / grounding - IEEE 142.Suitable ingress protection provided- e.g.IP-52

Suitable explosion proof enclosures where reqd.

(Contd)


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ISO-9001:2000

Safety Aspects in Electrical Design

Contd...

Lighting transformer - to ensure

personal safety

Corrosion prevention for jacket and pipelines- DNV RPB 401.

Navigational aids - international association

of light house authority (IALA).


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ISO-9001:2000

Safety Aspects in Piping Design

International codes and standards - ASME

B31.3, 31.4, 31.8, API RP 14E, 14C, 14G are

followed.

Thermal insulation provided for personnelprotection.

Handrails and access platforms for safe

operation.

Valves in hydrocarbon service - fire safe

design. Chemical hoses are fire resistant.


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ISO-9001:2000

Safety Aspects in Structural Design

International codes API RP 2A, API RP 2L/ICAO etc.

are followed.

Platform Structural design : FOS -1.5 under 100 yearsextreme storm conditions and FOS 2 for Operating

storm conditions. Most stringent is considered..

Riser protector and barge bumper provided.

Fire wall Isolation between Well area and others.


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ISO-9001:2000


VESSEL COLLISION:-API Guideline:

IMPACT ENERGY (REF API RP2A CL.18.9.2 ):-

KINETIC ENERGY E= 0.50aMV2

a-ADDED MASS- 1.4 FOR BROAD SIDE COLLISION & 1.10 FOR

BOW/STERN COLLISION, M- VESSELMASS ;

V-VELOCITY OF VESSEL IMPACT

MINIMUM SPECIFIED REQUIREMENT:

IMPACT OF 1000MT VESSEL AT IMPACT VELOCITY OF 0.50M/SEC.

(EQUIVALENT TO A TYPICAL 180-200 FEET LONG SUPPLYVESSEL IN GULF OF MEXICO.)

VESSEL MASS TO BE INCREASED OR DECREASED FOR DEEPER

AND SHALLOW LOACTIONS RESPECTIVELY.


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Design criteria Riser protector

Capability to absorb 100 TM energy on impact

Protector should be minimum 300 mm clear

distance away from riser Easily removable/ replaceable

Sign board DO NOT BERTH to dissuadeberthing of vessels

Typical Level: (-) 1.80 m to (+) 6.00 m


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Typical Riser Protector


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Typical Boat Landing & Barge Bumper


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Design criteria Barge bumper

Design to absorb 30.0 TM impact energy in middle 1/3

of post

Design to absorb lateral vessel impact of 11.0 TM

energy in middle 1/3 of the post

Typical Level: (-) 2.0 m to (+) 6.5 m


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ISO-9001:2000

Safety Aspects in Pipeline Design

International codes DNV OS-FS101, DNV RPB-401,

API 1104, API 1110, 1111 are followed.

Stability analysis, stress analysis, collapse and

buckling analysis etc. are carried out during design.

External corrosion protection by coat wrap along with

CP.

All pipeline hydro tested to ensure capability of

withstanding maximum operating pressure.


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ISO-9001:2000

Safety Aspects in Mechanical

Equipment Design

Pressure vessels are designed in accordance with

ASME Code section VII DIV.1.

Rotating equipments are specified in accordance with

related API codes and recommended practices.

Evacuation / escape routes are marked withluminescent paints for easy identification.

Condition monitoring instrumentation provided with

all critical items larger than 150 KW consistent with

accepted industrial norms.


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enhancing safety during design stage

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