Zeeshan Hyder

INTERNSHIP REPORT

INTERNSHIP REPORT KANDHKOT GAS FIELDPAKISTAN PETROLEUM LIMITED.

Zeehan Hyder Baloch | Dawood UET, Karachi

PREPARED BY: Zeeshan Hyder

B.E Chemical (2nd YEAR)

FROM: Dawood, UET.

Duration: 22th June to 28nd July 2015.

Email: [email protected]

Contact: 0300-3447458

mailto:[email protected]

INTERNSHIP REPORT

CONTENTKandhkot Gas Field Overview

Health Safety and Environment

Departments

Utility Area

Process Area

Process Description

DHP plant

Condensate Recovery System

Slug Catcher

Slug Vessel/low pressure Vessel

Oil/Condensate Seprator Tank

Oil/water Seprator

Glycol dehydration Unit

Gas Inlet Scrubber

Up/down Stream Filter

Absorption tower

Fins fan air cooler

Glycol Regenration

OVERVIEW OF KANDHKOT GAS FIELDKandhkot Gas Field is the second largest gas reserve of Pakistan Petroleum Limited after Sui Gas Field. Kandhkot is a small city of SINDH situated in District


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Kashmore, 65km south west of “Guddu” Barrage having mining lease area 284.274 sq km. In 1959 field was discovered but it was commence in 1987. Kandhkot gas field have three gas bearing Domes. South East Dome, North-east Dome and West Dome. Each dome have different formation. South-East Dome consist of SML (Sui Main Limestone), SUL (Sui Upper Limestone) and HRL (Habib Rahi Limestone) formation.North-East Dome consist of SML and SUL formation. West Dome consist only SML formation. Total 32 wells in which well no 1 is abandoned. 31 wells give the production. Total approximation of gas produced 197MMSCFD and condensate recovery of 8000 lit/day.

ACKNOWLEDGMENT “In the name of Almighty ALLAH the most gracious and the most merciful”

I reported Pakistan Petroleum limited (PPL) on 22th June 2015 as an internee in Chemical department and completed my internship on 17nd July 2015, where I ascertain my technical knowledge.


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Special thanks to the following people who had been very friendly, co-operative with me throughout my internship period in PPL made it possible for me to learn and gather information.I am very thankful to:

KFGCSMr. Engr. Tashfeen Ahmed (senior engineer operation)

Mr. Abdul Hafeez Babar (shift Incharge C.R)Mr. Nasir Farooqui (Shift Incharge)Mr. Engr. Naseer Khan (shift incharge C.R)Mr. Engr. Younis Jawed (Shift Incharge C.R)Mr. Engr. Qamar Ul Islam (Shift incharge C.R)Mr. Muhammad Tayyab (technician)Mr. Faisal Manzoor (Technician)Mr. Khalid (Technician)

DHP Mr. Aarab Bhayo (DCE)Mr. Pir Muhammad Shah (Senior Engineer)Mr. Muzzamil (Shift Incharge)Mr. Rameez Ahmad

Health, Safety and Environment

I got the basic tips and information about the safety of the plant, personal safety, and safety of fellow workers. Information about the importance of safety equipments like Helmet, Safety shoes, Gloves, Well fitted suiting & other equipments, as goggles, ear plugs etc

They also give brief information about the following.


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Plant entry and checking system Emergency response, Fire alarm system.

In present, HSE is conducting three policies:

1-Health Safety and Environment Policy

2-Smoking Policy

3-Seat Belt Policy

HSE Policy:

HSE gives the topmost priority to the health and safety of its employees. This policy states that every employee should wear the PPE’s (Personal Protection Equipment) before going to work in plant. This will minimize the possibility of getting harmed.

Smoking Policy:

Smoking at all locations in plant is prohibited except the locations named as Smoking Areas.

Seat Belt Policy:

Every employee should wear the seat belt while driving, and vehicle speed must not be greater than 20km/hr

Kandhkot Gas Field


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Dehydration plant KFGCS

Production and maintenance Operation Maintenance Control Room

Mechanical Electrical

Mechanical Workshop

Primary function of mechanical workshop is to give mechanical services to run the plant. This workshop is responsible of maintaining mechanical equipments such as valves, flanges, shafts, etc and rotary machines those cause problems such as pumps, compressors, turbines etc.

Electrical & Instrumentation/Control room

Whole plant is being monitored by engineers in control room. If any of the system is not working properly then electrical and mechanical department would be permitted by them to investigate and to sort out the problem

Utility Area

This area comprises of

Power Generation

It includes three gas generators (GENSET A, B and C) and one diesel generator use for emergency. One of these GENSETS is isolated so that can be used for maintenance purpose.

Reverse Osmosis (RO)Zeehan Hyder Baloch | Dawood UET, Karachi

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It includes sedimentation of water to reduce its TDS and to make it portable for personal usage.

Inert Gas System

Nitrogen is an inert gas so is being collected from air for two purposes. One is used as sealing element for compressor’s shaft so that lube oil and raw gas cannot be react each other and other is to purge gas from pipes to prevent wear. Inert gas compressors are used to compress it.

Fire Water system

In case of fire or any other emergency jockey and diesel pumps are planted, collect water from storage tanks so that situation can be controlled with in no time.

Air Compression Package

Air is being filtered to remove its moisture content and being compressed to instrumentation vessel for instrument purposes such as pneumatic valves and plant vessel for plant purposes such as gas turbine.

Storage Tanks

Storage tanks are used to store water. Two storage tanks are located, one is fire water tank and the other is portable water tank.

Cooling Towers

Two cooling towers are linked with GENSETS to cool generators by using LT and HT heat exchangers. Positive displacement diaphragm pumps are used to inject chemicals in water so that scaling would not be occurred on heat exchanger plates.

Process Area

This area comprises of

Compressors


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Three centrifugal compressors are used to increase pressure of gas up to 47bars. Out of these one is used as standby. These are seven stage driven by Gas turbine respectively (TUCO A, B &C) also called as Train.

Scrubbers

These scrubbers are separators used for the separation of process liquid from gas. Three scrubbers are linked with each train named as SUCTION, INTERSTAGE & DISCHARGE.

Inlet Gas Filters

Working principle of inlet gas filter is to remove solid content from gas to prevent erosion in impellers. Three gas filters are interconnected with scrubbers, out of these one is isolated.

Gas Turbines

A twin shaft gas turbine comprises of eleven stage compressor and four stage itself turbine is used to drive centrifugal compressors. The compression ratio is 16.7:1 and 13Mega Watts is its capacity and present utilization is up to approx 4Mega Watts. These gas turbines can be called as generators. A shim pack coupling is used to couple these generators with centrifugal compressors. Operating temperature can be controlled by ventilation ducts.

Flare Knock Out Vessel

Gas from various equipments is vented to atmosphere through flare K.O vessel and is burnt out through flare stack. This also helps in flaring the gas in case of any equipment shutdown or if any safety gets operated.

Fin/Fan Coolers

Coolers are used to control temperature of gas that is compressed by centrifugal compressors.

Slug Catchers

Overall eight slug catchers are connected horizontally with KFGCS Plant. Working principle is to separate gas from liquid with the help of gravity.

Corrosion Inhibitors

Corrosion inhibitors are using PD pumps to inject chemicals in pipes so that inner walls may not be corroded.


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Process Description

Separated gas from slug catcher will be filtered through gas filters for solid particulate removal. Gas Filters are proposed to provide filtered gas for compression system.

After passing the filters the gas enters the compression system. Each compression train will incorporate scrubbers to remove liquid and droplets in the incoming gas stream.

Phase-1 compression will be provided with two stage gas compression i.e. interstage and discharge stage. Interstage and discharge gas cooling will be provided by fin/fan type air coolers. Compressed gas from all running compression trains will be routed to inlet of existing dehydration plant (DHP).

During phase-2 (2017-2031) when the inlet pressure to the gas plant drops to 50 psia, the system utilizes an additional two compression stages per train to achieve the delivery pressure.

Dehydration Plant:

This is most important part of this field. Here the gas from well is dehydrated, which means the water and moisture content and all condensate is removed from gas and make it completely dry. Then it is supplied to the consumers and KFGCS as turbine fuel and to operate generators. DHP plant production started from 1987 and its capacity 360 MMscd. DHP plant consist of Slug catcher system/condensate recovery system, Dehydration unit and Glycol Regenration Unit.

Process:


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Initially gas from well having a pressure of about 200 KPag is received in DHP plant then it is sent to KFGCS where the pressure is increased to 600 KPag. The gas coming from the KFGCS is first pass through a scrubber having 12 fingers where gas strikes and water is separated from it. Gas in then treated with Tetra Ethyl Glycol in absorption tower, where gas is enter from bottom of the tower and glycol from top. They both interact and water from gas is absorbed by glycol. Glycol is then drained out from bottom and dry gas from top. The dry gas by passing through filters is sent to the consumers.

All water separated from gas at any stage is then sent to the storage tanks. Where the condensate is separated In condensate towers by means of density difference.

Condensate Recovery System

Slug Catchere:-

Kandhkot Gas Field have two main section line from wells to DHP for transportation of (Gas+slug). (Gas+Slug) transfer to slug recovery system to seprate gas and recover condensate from gas. Slug catchere consist of main header line and 12- 13" pipe line. 12- 13" pipe lines also called 12 fingers. Slug fingers attach at 45° with main header line.

(Gas+slug) enter in main header line and seprate on the top of lieader, sent to KFGCS for increase of its pressure and slug slide to fmgers due to gravity difference. At the other end of slug cature slug header line, in which slug collect and enter to next slug vessel or low pressur vessel to seprate remain gas.


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Slug Vessel/Low pressure Vessel:-

Slug enter from top the vessel and contact with reflecting plate than reduce its velocity and due to high density slug settle donwn to bottom of veesel. Remain gas also contact with reflecting plate, seprate due low pressure of vessel and low density to top of vessel. Slug transfer to oil/water Seprator Tank to seprate oil from water and seprate gas sent to Air conditioning vessel to remove H2S.

Oil/Water Seprator Tank:-

Oil/Water Seprator Tank Consist of three section top, cent, bottom in tank. Slug enter from the top of the tank. Slug distribut in two section, water collect in bottom. condensate flow over water in center due to low density than water. Condensate transport through two pump to condensate storage tank. Condensate sale out to PRL (Pakistan Oil Refinery Limited). Bottom water have little amount of condensate. Water sent to Oil/Water Seprator to seprate oil from water.


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Oil/Water Seprator:-

Oil/Water Seprator consist of two portion, one of them large other small in size. oil/water enter from the top of large portion , large amount of water settle down in bottom of portion. Min amount of Oil flow over on water and sent to second portion of seprator, further sepration occur on the basis of density. Oil seprate from the top of second portion. Water also seprate from bottom of large portion. Water sent to the water pond and Oil sent to condensate storage tank.

Dehydration Unit:-

Inlet Scrubber:-

Three Inlet Scrubber installed in DHP, one of them use for plant start up and others use for process. Gas from KFGCS enter inlet scrubber for seprate exist minimum amount of water. Gas enter inlet scrubber and contact with reflecting plate, than reduce water velocity. Water setlle down in the bottom of scrubber due low velocity and high density than gas. Water drain out of scrubber through valve. Gas also contact with reflecting plate due low density, escap from top portion of scrubber and transfer to up/stream f1lter for filtration of dust partical and little amount of water.

Absorption Tower/Contact Tower:-

Four absorption tower installed in DHP. On of them called SDHU (Stand by Dehydration Unit) and other called unit-2, unit-3, unit-4, respectivily but Unit-2 not operate due some problem.


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SDHU vertical tower consist of two section, upper and lower section.In upper section gas contact with TEG to seprate from water, lower section called scrubber in which water seprate on the basis of density. Gas enter from the bottom of tower and after contact with glycol seprate from top of the tower.

Lean glycol shower from the top of tower and drain out from the bottom of the tower for regenration. Gas enter contact with reflection plate in lower section, water settle down int bottom and gas pass through demister pad to remove dust than gas enter in upper section through chimney tray.


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Dry gas pass though fins air cooler to reduce dry gas temprature. Fins air cooler consist of two fins fan, tubes. Fan attach from the bottom of cooler, heat exchange with atmospher air and sent to the sales metering skid. Glycol Regenration:- Rich glycol discharge from the bottom of upper section of absorption tower. We want to recycle rich glycol. Glycol regenration operation that convert rich glycol into lean glycol for reuse in absorption of natural gas.

Description:-

Rich glycol discharge from absorption tower after absorb water from natural gas. Lot of amount of water prensent in glycol, glycol sent to reboiler for removal of water by evaporization. Glycol also contain some content of natural gas.

Rich glycol transfer to flash seprator through PD pump. Rich glycol sent to flash seprator to seprate gas from glycol.due to low pressure and high temprature of flash seprator, gas seprate out from the top of horizental vessel and glycol settle down in the bottom. Natural Gas used as for fuel for burner and flare. Natural gas have sulfer impurties like


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hydrogen sulphide, necessary to remove these impurties from gas before burnig.Therefore natural gas sent to the air conditioning veesel to remove hydrogen sulphide and natural gas used as fuel for burner and flare system. The remainig glycol from the flash seprator tranfer to glycol filter and charco! filter for further purification of glycol. After then rich glycol sent to plate and frame heat exchanger to gain heat from lean glycol

Lean glycol shower over rising water vapour to evaporate water from rich glycol in the still column and rich glycol glycol convert into lean glycol, settle down in the reboiler for further evaporation. Lean glycol store at specific level in rcboiler and after achieve this level drain out from reboiler to surg tank to store. Lean glycol tranfer to absorber for recycle through PO pump from surg tank.

Therefore natural gas sent to the air conditioning veesel to remove hydrogen sulphide and natural gas used as fuel for burner and flare system. The remainig glycol from the flash seprator tranfer to glycol filter and charco! filter for further purification of glycol. After then rich glycol sent to plate and frame heat exchanger to gain heat from lean glycol.

Lean glycol shower over rising water vapour to evaporate water from rich glycol in the still column and rich glycol glycol convert into lean glycol, settle down in the reboiler for further evaporation. Lean glycol store at specific level in reboiler and after achieve this level drain out from reboiler to surg tank to store. Lean glycol tranfer to absorber for recycle through PO pump from surg tank.

THANK YOU


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Zeeshan Hyder