TEKNICA (UK) LTD - WAHA OIL COMPANY

CONTENTS PAGE NO.

INTRODUCTION

ENVIRONMENTAL CONDITIONS & GENERAL DESIGN CRITERIA

DESIGN PRINCIPLES

General

Utilities

Types of Control and Sensing Mediums

Field Instrument Signal Ranges

Selection Criteria for Field Instruments

Mounting of Field Instruments

Environmental Protection

Pneumatic Instruments

Instrument Cables

Identification of Instruments

1.0&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; INTRODUCTION

This document describes the Field Instrumentation Design philosophy for Faregh Field Phase II Development by the Waha Oil Company - Libya.

The purpose of the Faregh Phase II Development is to produce Sales Gas gas and condensate from gas caps associated with the oil reservoir comprising the Faregh field.

The Faregh Phase II Facility will typically comprise of the following: -

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Gas Gathering initially from eight, (8) wells, increasing to an estimated of forty five, (45), wells.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Gas Separation

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Liquid Removal

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Gas Compression

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Sales Gas Metering into the Faregh Phase I Export Gas Pipeline to Zuetina.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Condensate Stabilisation

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Condensate Export through the Crude Oil Pipeline to Gialo

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Automatic well testing

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Fire Detection System in Phase II Equipment Building.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Gas Detection in Compressor Houses.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Utilities (Flare Gas, Instrument / Plant Air)

2.0&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; ENVIRONMENTAL CONDITIONS & GENERAL DESIGN CRITERIA

For environmental conditions andAND General Design Criteria refer to Specification No 5906G - GL - GE - 7000 - 00: - Equipment General Design Criteria.

DESIGN PRINCIPLES

General

Field instruments are defined as instruments located without in the confines of a control room process plant area, which measure, indicate, and / or control process parameters.

The criteria for the selection of field instrument shall be as follows: -: -/ electronic typescontrol loop requiring recalibration / maintenance.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Rapid loop response to changes due to process variation and operator initiated commands / changes. In order to minimise time distant / velocity lags within the process control loop, any change detector in the control medium loop shall be as close as possiblepractical depending on control and engineering requirements to the final control element, i.e. change from electrical to pneumatic shall be close to at the pneumatic control valve. I/P converters shall not be mounted on control valves where vibration is likely to be a problem.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; In order to minimise the field instrumentation inventory on Phase II facility, it is proposed to standardise on instrument manufacturers for non-packaged field instruments and for instruments on packaged equipment by using the WAHA approved list of instrument manufacturers.

In the case of the package equipment supplier the WAHA approved list of instrument manufacturers will be included as an attachment to the packaged equipment specification.

This will ensure that only WAHA approved instrument manufacturers are used on the Phase II Development.All field instruments in contact with process fluids shall have a physical barrier between the process wetted section and the electrical section containing the cable terminations, the method of sensing the change in the parameter value will be by using a non invasive method, i.e. magnetic used.

Utilities

The following utilities shall be available for the field instruments within the Phase II battery limits: -

Instrument Air

The instrument / plant air packaged unit will deliver instrument air at the following pressures: -

Minimum 65 psig

Normal  78 psig

Maximum 110 psig

Design 150 psig

Electrical Supplies

The supply for all electrical / electronic field instruments will be based on
24 Volts DC. The exception to this will be field located solenoid valves where the operating voltage will be 120 V AC 60 Hz to avoid voltage losses on DC circuits due to long cable runs.

All electrical power for electrical / electrical fField ield instruments connected to the CCS will receive power from the CCS. The CCS will, in turn, be derived powered from its dedicated dual redundant Uninterruptible Power Supply (UPS) sources. The process field instruments will derive their electrical power from the dual redundant process control UPS, whereas field instruments associated with the ESD system will derive their electrical power from the Safety System UPS

Types of Control and Sensing Mediums

Control Mediums

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a)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Instrument Air

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The main actuating controlling medium for the final control element in the field, such as valves, dampers, etc will be pneumatic. The pneumatic supply will be derived from dedicated oil free instrument air compressors / drier packages complete with plant air and instrument air receivers.

The quality of instrument air delivered to the instrument air header will meet the requirements of ISA-S7.0.01. The pressure dew point as measured at the dryer outlet and at maximum air throughput will be at least ^oF (10 ⁰ C) below the minimum ambient temperature of 30 ⁰ F, i.e. 12 ⁰ (-12 ⁰ C)

The instrument air receiver capacity will be sufficient under normal operating conditions, to maintain the instrument air pressure at 78 PSIG or above for a minimum period of 15 minutes, in the event of a total shutdown of the air compressor package.

The instrument air system will be designed for all loads envisaged during normal operations plus a minimum of 20% future expansion to the system.

Distributionve piping shall be sized to ensure that the pressure drop between the supply package and the most remote consumer does not exceed 5% of the normal system pressure.

The size of the main instrument air header shall be based on an average air consumption of 0.5 SCFM per user.

In the case of on / off type pneumatic loops the actuating pressure for the final control element may be up to the main instrument air supply pressure.

b)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Electrical (DC / AC)

Electrical control will apply to directly acting electromechanical devices such as field located solenoids valves and electrical relays in MCC's and Switchboards Cabinets. The power supply will be as follows: -

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Solenoids shall have a control voltage of 120 V AC 60 Hz

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Electrical Relays in CCS system interface cabinets shall normally have a control voltage of 24 V DC, although an AC control voltage may be used in certain circumstances.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Full tagging and segregation shall be applied where components / wiring operating on different voltages are installed within the same CCS system interface cabinets

c)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Hydraulic

For certain field instruments where a high-pressure actuating control medium is required to actuate the final control element, i.e. pipeline isolation using Emergency Shutdown Valves, (ESV)'s, the control medium will be hydraulic.

The hydraulic supply to the field instrument will be derived from a self-contained hydraulic power pack comprising of pumps, accumulators, controls, etc, and may utilise either an electrical, pneumatic or (pipeline gas source to pressurise actuate the hydraulics system.

The method of actuating controlling the final actuating device may be electrical, i.e. an electro hydraulic solenoid valve in the hydraulic circuit, if the final control device is located within Faregh station, or to a pipeline gas operated pilot valve in the hydraulic circuit if the final control element is located outside the Faregh station

Sensing Mediums

The main sensing medium for directly mounted field devices for process and safety system field instrumentation, such as transmitters, switches, etc, will be the process fluid, in its gaseous or liquid form.

For local indication the parameter value process variable will be taken directly from field instrument such as pressure gauges, level gauges and flow gauges.

For remote indication, the field instrument will normally convert the measured parameter value into an electrical signal for transmission to the Central Control System (CCS).

Field Instrument Signal Ranges

The field instruments will be selected to operate on standardised signal ranges. The following signal ranges will be used: -

a)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Pneumatic

The standard signal range for pneumatic modulating type control loops will be 3 to 15 psig. Other signal ranges may be used in instances where higher operating pressures are required by the pneumatic control device Split ranges shall be used to control multiple final control elements, as necessary.

b)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Electrical

For analogue electrical signals the standard signal range will be
4 to 20 mA DC.

An exception to this will be specialised electronic equipment, i.e. flow measurement systems using transmitters with pulsed / frequency outputs, vibration monitoring systems and high temperature measurement, i.e. RTD's and thermocouple devices systems, etc that using e milli-volt signals. In such cases, in order to minimise the cable length, the signals will be converted to the standard electrical signal range, using certified field located signal converters.

Selection Criteria for Field Instruments

a)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Electrical Classification

All electrical field instruments will be certified for use in hazardous areas by an internationally recognised certifying authority. Recognised certifying authorities are listed in ISA RP12.1.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Instruments located in classified areas shall be classified as for use in either Div I or Div II areas as determined from the applicable hazardous area classification drawings.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; In general, electronic field instruments will carry approval for installation in Zone I Gr II A and II B or Class 1 Division 1 Groups C & D hazardous locations.

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; All electronic items will have RFI protection. Output errors caused by radio frequency interference (RFI) shall be less than 0.1% of calibrated span for exposure to field strength of 10 Volt/meter, at a distance of 3 feet, or on a frequency range of 10 - 1000 MHz.

b)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Weatherproof Classification

&nbs 17317x2321r p;

All field instruments will be weatherproof to NEMA 4x or provided with ingress protection to IP 65 in accordance with IEC-529.

c)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Materials of Construction

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Materials of construction of field instruments will be specified on the instrument data sheets. and generally will be the same as materials stated in the relevant piping specification.

Instrument tubing shall be seamless and fully annealed, Grade 316 stainless steel per ASTM A269 with Rockwell hardness not to exceed B-80.

Pneumatic tubing shall be 1/4 inch OD, with 0.035" wall thickness. If an increased capacity is required consideration shall be given to the use of 3/8 inch OD with 0.035 minimum wall thickness or inch OD with minimum wall thickness

d)&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Connections

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It is the intention to standardise on all field instrument connections as far as possible. Connections will be as follows: -

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Air supply and pneumatic signals: inch 3/8 inch or inch
NPT female

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Electrical connections: ½ inch or ¾ inch NPT female

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Process connections: The type and size of instrument process connections will be dependent on the process requirements and applicable piping specification, and will be indicated on the respective instrument data sheets.

3.6&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Mounting of Field Instruments

When remotely connected, and where practical, All field instruments will be mounted on instrument stands above grade. The exception to this rule will be instruments on pressure vessels where the instruments are mounted on instrument bridles or directly mounted on the vessels, i.e. level instruments, pressure gauges, temperature gauges, etc. Some instruments such as pressure gauges will also be directly mounted on to process lines.

Environmental Protection

As applicable All instruments will shall comply with the environmental conditions given in Specification No 93275906G - GL - G - GE - 7000 - 00 - Equipment General Design Criteria. In addition, instruments will also be protected, as far as practicable, from direct sunlight by the use of sunshades. This will be particularly applicable to delicate electronic solid-state type instruments. On skid mounted equipment packages where the instruments are located on a skid mounted local panel protection from direct sunlight shall also be provided.

Pneumatic Instruments

Pneumatic type controllers will be restricted to local loops. Controllers shall incorporate high and low alarms to indicate control malfunction and general excursions outside pre set limits.

All pneumatic field instruments operating at pressures lower that the main instrument supply pressure will be fitted with air filter / regulator type devices upstream of the field instrument, i.e. air sets.

In addition to the air filter / regulator type devices upstream of the field instrument, all pneumatic metal to metal contact type devices such as piston type actuators will also be fitted with oil lubricating devices, i.e. oil mist type lubricators to prevent stiction or galling / scouring. The lubricators will be located between the air filter / regulator device and the pneumatic field instrument.

All instrument impulse and pneumatic tubing will, as a minimum, be AISI 316 stainless steel unless the piping specification dictates otherwise.

In instances where instruments are connected to process lines using impulse tubing the primary isolation valve will be in accordance with the applicable process piping specification. Where required by the piping specification double isolation shall be provided in high-pressure service. A secondary isolation device shall be provided at the instrument itself. will be provided to isolate the instrument impulse line from the process pipe work The secondary isolation device will be AISI 316 stainless steel block and vent valves or 3 or 5-way block and vent manifolds.

3.9&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Instrument Cables

All instrument cabling associated with the Faregh Field Phase II Development shall be supplied in accordance with the cable specification originally developed for Faregh Field Phase I Development, updated where necessary, to suit the particular requirements of the Phase II facilities.

3.10&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Identification of Instruments

All field instruments and associated field accessories, such as pneumatic and electrical JB's, cables and their individual conductors, pneumatic tubing runs, electrical and pneumatic terminations, etc, will be properly identified in accordance with the relevant sections of the approved project procedures. As a minimum, the identification tag / nameplate will include the following: -

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Instruments and instrument housings located outdoors shall be provided with two trayffolyte (white/black/white) stainless steel tag plates. One shall be securely attached to the instrument (not part of manufacturers nameplate), the other securely attached to the instrument housing or permanent supporting structure. Stainless steel self-tapping screws are acceptable. Drilling of explosion-proof housings is not permitted, as this will invalidate the hazardous area certificate of the instrument.

The use of adhesive for affixing the nameplate / tag is also not acceptable, as the use of adhesive nameplates / tags is not regarded as a permanent fixture. . The size of the lettering on the nameplate will be 3/8" " minimum

·&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p;&nbs 17317x2321r p; Instruments located indoors will be provided with an engraved laminated trayffolyte (white/black/white) plastic tag plate securely attached to the instrument with self-tapping stainless steel screws. Each tag plate will have black engraved lettering on a white background. The size of the lettering on the nameplate will be /₈" 3/8 " minimum

All warning nameplates, i.e. AC voltages higher that 120 Volts AC, will have red engraved lettering on a white background. . The size of the lettering on the nameplate shall be ¹/₈" 3/8 " minimum

All instruments shall be fitted with the manufacturers nameplates. Nameplates shall include the following information as applicable:

- Manufacturers name, model and serial numbers

- Date of manufacture (month/year)

- Engineer's purchase order number

- Rating of pressure retaining parts

- Set pressure and temperature

- Operating range

Materials of wetted parts

- Nameplates shall also carry information relating to electrical supply Voltage, frequency, air supply pressure and hazardous area certification details.