a report of training ongc

8/4/2019 A Report of Training ONGC

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A

REPORT ON TRAINING

IN

OIL AND NATURAL GAS CORPORATIONLIMITED

SURFACE TEAM

AHMEDABAD ASSET

SUBMMITTEDBY: -


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ACKNOWLEDMENT

Fi r s t ly , we would l ike thanks Mr . N. Khandur i fo r h i s g rea t e f fo r t s ina r r an gi ng ou r training at Ahmadabad asset under surface team. We would like to express our

sincere thanks to installation managers of GGS motera KALOL,C.T.F, G.C.S ,G.C.P, KALOL

G.G.S VII , E.T.P, C.W.I .P, Nawagam C.T.F, Desalte r plant, Artificial lift & security dept.O.N.G.C AHMEDABAD. We express our deepest thanks to Mr. M.G Desai (Head of

Chemical Engg Dept .) for providing us the moral support and encouragement, without which it

would have been difficult to complete this training.

Preface

Theory o f any sub jec t i s impor tan t bu t wi thou t i t s p rac t i ca l knowledge i t

becomes use less , pa r t i cu la r ly fo r t echn ica l s tuden ts . A techn ica l s tuden t

cannot become a perfect engineer or technologist without practical understandingof their branch, hence training provides a golden opportunity for all technical students to

interact with the working environment. The principal necessity of in-plant training is to get details

about unit operation and unit process which are carried out in chemical industries and toknow more about the equipments used in these industries. The in-plant training pr ogram is

very advantageous for the technical students who have a vivid idea about the industries.

Th is t r a in ing he lps to unders tand the bas ic concep t o f the indus t ry . Dur ing

th is pe ri od th e students becomes aware of the problems faced in the plant and are alsoaware of the industrial atmosphere and also with the industrial people.

CONTENT

- 3

TOPIC PAGE NO

1. GGS Moter 1

2. KALOL GCS (GAS COLLECTION STATION) 6

3. GAS COMPRESSION PLANT (GCP)-KALOL 11

4. CENTRAL FARM TANK (CTF)-KALOL 15

5. GGS VII-KALOL 20

6. EFFLUENT TREATMENT PLANT (ETP)-II (KALOL) 26

7. CENTRAL WATER INJECTION PLANT (CWIP) 30

8. CENTAL TANK FARM (CTF)NAWAGAM 339. DESALTER PLANT: NAWAGAM 35

10. WWTP-WASTE WATER TREATMENT PLANT 39

11. ARTIFICIAL LIFT (Ahmedabad) 43

GGS-MOTERA

INSTALLATION MANAGER - Mrs. Purvi Dutta choudhary

- 4 -


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DATE OF COMMISION:29.03.1992

AREA OF INSTALLATION: WELL PRODUCTION STATUS: TOTAL WELLS CONNECTED-

33TOTAL FLOWING WELLS-28TOTAL LIQUID PRODUCTION-40 m3/day. WATER

INJECTION WELLS- nil GAS INJECTED-20000 m3/dayVESSELS: LOW PRESSURE SEPARATOR- (vol- 6 m3) GROUP SEPARATOR- (vol-6 m3) TEST

SEPARATOR- (vol- 6m3) VERTICAL SCRUBBER-(capacity-1.7 lacks m3/day)HORIZONTAL

SCRUBBER-(capacity- 50000 m3/day)BATH HEATER- 1 NO.S TANKS OIL STORAGE TANKS-3 NO.S (45 m3)

FUNCTION:At group gathering system (GGS) fluid from various wells is collected in header from various wells

through pipeline network. Then the low pressure fluid (1- 2 kg/cm2) goes to the low pressure

separator, and then in the output we get separated oil and gas. Oil goes directly to storage tanks and

gas goes to common sucker separator. On the other hand fluid of 4-5 kg/cm2 pressure goes to groupseparator. Then from the outlet of this separator gas goes to common suction separator and oil goes

directly to storage tanks. Then in common suction separator all the gases from the outlet of group

separator and low pressure separator is further separated, thus if any amount of oil is still present ingas can be separated. So after separation gas is directly sent to GAIL and oil goes to storage tankThe gas which was present in above withdrawn oil is low pressure gas, but some high pressure gas

also comes out of reservoir. So that gas is sent to gas scrubber where whatever amount of gas is

present in gas is separated and the gas what we get after separation is not suitable for consumers so itis sent back to reservoir for artificial lifting.

GGS FACILITIES

1. PIPELINES

For oil- 4inches in diameterHighly resistant against corrosive action of fluid

For gas- 2inches in diameter

2. SCRUBBERS

Horizontal scrubber

Function- extract oil from gas Pressure- 40 Kg/cm2

Vertical scrubber

Function- same as above Pressure- 70 Kg/cm2

3. SEPARATOR:

To flash the well fluid to separate into liquids and gas at a controlled pressure.

Flow lines from various wells open into the pipelines of GGS. Various provisions for varioussupplies to 3 types of separator:

TEST SEPARATOR


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Fluid enters tangentially and due to the sudden pressure drop to the set level , the fluid gets separatedinto separated into liquid and gases. Baffles are fitted inside the separator to help in better separation.

It is used for testing the fluid obtained from a source. It can withstand pressure of 9 kg/cm2.

GROUP SEPARATOR

It is also a two phase vertical cylindrical vessel just the same as the previous one but here fluid from

all the well comes whose pressure is up to 4-5 kg/cm2. Separated gas is sent to flare lines.

LOW PRESSURE SEPARATOR

When the fluids coming out of the wells have pressure of about 1-2 kg/cm2 then fluid goes tothisseparator. All these separators have same capacity.

4. VALVESGate valves: used to minimize the pressure drop in the open position and stop the flow rather than

controlling it

Check valves: it is one-way valve which normally allow fluid to flow through it in only one

direction. This prevents the back flow of fluid into wells.

5. STORAGE SYSTEM

Purpose:To store oil before transporting

To measure oil produced Process:

Oil from bath heater and separator is taken into overhead cylindrical tanks for measurement.

6. OIL DISPATCH SYSTEM

Purpose:To dispatch oil from GGS to CTF. Process:

Oil stored in the storage tanks is sent to CTF by road tanker as there is no pumping system

available in the installation.

7. BATH HEATER

Used to reduce the viscosity of oil coming from reservoir by heating that oil in bath heater.

8. FIRE FIGHTING SYSTEM

Large water tank- (capacity- 350 m3)

Small water tank- (capacity- 100m3)


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KALOL GCS (GAS COLLECTION STATION)INSTALLATION MANAGER : Mr.B.B.Patel

ESTABLISHED IN : 1973


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RECEIVING STATUS :Total Wells Connected-32Total Working Wells- 13Receiving pressure-4kg/cm2

OBJECTIVES:

To collect natural gas from wells

To collect associated gas from GGS

To send gas to GCP.To send compressed gas (CG) to GGS for artificial lifting

To send CG to IFFCO, RIL, etc.

FUNCTIONS:

Its main function is gas collection and distribution. GCS receives associated gas from GGS andnatural gas directly from the wells. They both are mixed in scrubber, treated and they are transferred

to GCP for further compression. Now the compressed gas is again received back by GCS and then the

compressed gas is sent to various destinations.

GCS FACILITIES

1. MANIFOLDS

Gas grid manifold (to provide high pressure compressed gas through 4 & 6 pipeline to northand south Kalol gas system)

2. BEAN HOUSING

To control the flow of gas from the reservoir

3. SCRUBBER

Purpose

It is a purifier that removes impurities from gas. Scrubber systems are a diverse group of air

pollution control devices that can be used to remove particulates and/or gases from industrial exhaust

streams. Traditionally, the term scrubber has referred to pollution control devices that use liquid to

scrub unwanted pollutants from a gas stream. Recently, the term is also used to describe systems

that inject a dry reagent or slurry into a dirty exhaust stream to scrub out acid gases. Scrubbers are

one of the primary devices that control gaseous emissions, especially acid gases. Process it involves

the addition of an alkaline material (usually hydrated lime and soda ash) into the gas stream to reactwith the acid gases. The acid gases react with the alkaline sorbents to form solid salts which are

removed in the particulate control devices. These systems can achieve acid gas (SO2 and HCl)

removal efficiencies.

4. SEPARATOR

Functions at 4kg/cm2In this only natural gas is separated to remove any condensed liquids if present. The gas firstly

goes to separator then to scrubber.

5. STORAGE TANK


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GAS COMPRESSION PLANT (GCP)-KALOLINSTALLATION MANAGER: Mr. Rajesh KumarDATE OF COMMISION: GCP-I: 26.02.1990GCP-II: 15.03.1994

TOTAL CAPACITY: 5 lack m3/day


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TOTAL COMPRESSORS: 106 in old plant and 4 in new plant Capacity (old) =3 lacks m3/dayCapacity (new) = 2 lacks m

3/day

REVERSE-OSMOSIS PLANT (R-O): twoDISCHARGE PRESSURE: 40 kg/cm2

PROCESS DESCRIPTION: In this plant, gas from GCS (gas collecting system) at 4kg/cm2 pressure

comes through pipe lines to GCP. Firstly it goes to common inlet separator, where the primary

separation is done, usually the content of oil in gas is negligible but if its there it gets separated. Nowthe gas goes to 1st stage suction separator, there further separation is done. Till now the pressure is

4kg/cm2, now this gas goes for first stage compression goes into compressor. After compression the

gas we get is of 12-14 kg/cm2 and because of compression temperature rises to 1250C so to lowdown

the temperature to 40-450C, compressed gas is sent to inter gas cooler. Now the cooled gas of 12-14

kg/cm2

pressure goes to 2nd

stage suction separator where further separation occurs. Then it goes to

2nd

stage gas compressor there compression is done and in the output we get gas of 40 kg/cm2pressure but temperature has again gone up to 1450C because of compression so it again goes to

cooler which is also known as after cooler . Now as cooling has occur so condensation will be done

so again whatever amount of oil will be there will be drained out from discharge separator. Then

finally gas from the discharge separator at 40 kg/cm2 pressure is sent back to GCS.

GCP FACILITIES

1. GAS COMPRESSION SYSTEM

PURPOSE

To compress gas at high pressure

PROCESS

It has two stage gas compression systems. First stage compressors takes gas from first suction

separator and other stage takes gas from second suction separator as shown in the flow diagram.

RPM= 990 Capacity-2100m3/hr

Model- 14 X 8 X 5 2 RDH-2

Make-Ingersoll sand

Type- double-acting reciprocating horizontal

Number of stages- Two

2. RAW WATER TREATMENT SYSTEM (R-O Plant)

Purpose:

to remove true deposit solids from water

Process

Firstly the raw water from the storage tank flows into pipelines and come into desired location. To

this raw water we add sodium hypo chloride which destroys the bacteria present in water. Then the

water is treated with sodium bi sulfate to reduce the chlorine content which would have increasedbecause of sodium hypo chloride addition. Then this treated water with sodium hexa meta phosphate

so that scaling can be minimized which will occur in tubing having membranes. Then this water goes

to multi grade filter where various types of gravel, sand are filtered. Then thefiltered water is treated


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with 98% H2SO4 so that pH of water is maintained. Then again this water goes to cartridge filter, sothat if any filtration is left can be completed. Now this filtered water is pumped into tubing system

having membranes with the help of high pressure pump. Then there high- quality demineralised wateris produced which is then sent to storage tanks.

3. AIR COMPRESSION SYSTEM:

Make- Ingersoll RandModel- 8 X 5 E&1-NL2

Discharge Pressure- 110 PSI

Capacity- 200 CFM(each)

4. COOLING SYSTEM:

Purpose:

There are two types of gas coolers inter gas coolers and after gas coolers. Its a type ofheat

exchanger. Running water through it helps in cooling of gas and they are sent finally to dischargeseparator. Inter gas cooler takes the gas of first stage compression and gas cooler takes second stage

compression.

Process:

Its a type of heat exchanger, it contains baffles and one shell and two tubes pass exchanger system.

Cooled treated water enters from one side and gas enters from the other side. There occurs a counter

current flow. This results in exchange of heat between two liquids and hence the fluid is cooled.

5. GAS DETECTION &MONITORING SYSTEM

Used to detect the leakage of gas in the plant


6 fire fighting pump

4 diesel pump and 2 motor driven pump

7. ELECTRICAL SYSTEM

Two 11 KV sub-station8 step down transformers


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CENTRAL FARM TANK (CTF)-KALOLINSTALLATION MANAGER : Mr. T. C. TiwariCOMMISSIONED IN: August, 1971


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OBJECTIVES:

Collection of oil from Kalol, Sanand, Jhalore, South Kadi ,Viraj , Paliyad, LimbodraTreatment of crude oil

Chemical analysis

Pumping oil to desalter Nawagam plant

Pumping effluent to ETP (effluent treatment plant)

RECEIVING SYSTEM

Crude oil received at CTF Kalol through.

8 diameter line from Sanand and Jhalore field at 1000m3/day.

12 and 8 lines from Kalol field at 170m3/day.

12 lines from south Kadi and Viraj field at 43m3/day.

COLLECTION

6000 m3/day

FUNCTIONS

Crude oil is received from various GGS. The oil which is having higher water cut is sent to

heater treater while oil having low water is directly dispatched to desalter.

TESTS PERFORMED

Test for specific gravity-

A hydrometer is an instrument used to measure the specific gravity (or relative density) of liquids;

that is, the ratio of the density of the liquid to the density of water.

A hydrometer is usually made of glass and consists of a cylindrical stem and a bulb weighted with

mercury or lead shot to make it float upright. The liquid to be tested is poured into a tall jar, and the

hydrometer is gently lowered into the liquid until it floats freely. The point at which the surface of theliquid touches the stem of the hydrometer is noted. Hydrometers usually contain a paper scale inside

the stem, so that the specific gravity can be read directly.

Test for water content (DEAN STARK METHOD) This method is used for determining water-in-oil. The method involves the direct co distillation of the oil sample. As the oil is heated, any water

present vaporizes. The water vapors are then condensed and collected in a graduated collection tube,

such that the volume of water produced by distillation can be measured as a function of the total

volume of oil used.

CTF FACILITIES

1. DISPATCH SYSTEM

Dispatch is done through 12diameter line, 51Km long pipeline to desalter Nawagamthrough topumps at 130 m3/hr rate.

6 effluent dispatch pump each of 50 m3/hr capacity.

Oil dispatch pump


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(A-700) BPCL 3 in number each of 120 m3/hr capacity. (C-558)BPCL 4 in number each of 135 m3/hr.

2. MASS FLOW METER

Coriolis meter

3. STORAGE TANKS10 tanks of capacity 2000 m3 out of which 2 are used for effluent storage and rest for storage of

oil.

8 tanks of capacity 10000 m3 for storage of oil.

4. SCRAPPER SYSTEM

There are two scrappers receiving platforms from 12 pipeline for S.Kadi and 8pipeline for Sanand- Jhalore field also there is one scrapper launching platforms for 12 pipeline desalter plant

NGM.

5. HEATER TREATERIn all 6 heater treater are there in this plant.

4 of which are of capacity 300m3/day.

2 jumbo heater treater are also there, one of which is of capacity 800m3/day and second one is of1000m3/day

One jumbo heater treater is under construction.

5 heater treater feed pump are available which are centrifugal and there capacity is 45m3/hr.

It has three chambers namely

Heating chamber

Middle chamber

Electrical Chamber HEATING CHAMBER: The fire tube which extends up to this section is in

submerged condition in emulsion oil. The heating of oil emulsion decreases the viscosity of oil andwater and reduces the resistance of water movement. The heat further reduces the surface tension

of individual droplets by which when they collide form bigger droplets. This progressive action

results in separation of oil and free water. MIDDLE CHAMBER: The fluids from heating enter intothis chamber through fixed water .It doesnt allow gas to pass into electrical chamber. The gas whichenters heating chamber leaves from top through mist extractor. The oil in this chamber is controlled

by oil level controller. ELECTRICAL CHAMBER: In this section constant level of water ismaintained so that oil is washed and free water droplets of water are eliminated before fluid proceeds

towards electrode plates (electric grid). These plates are connected with high voltage supply of 10000

to 25000volts. When fluid passes through these electrodes the droplets polarizes and attracts each

other. This attraction causes the droplets to combine; they become large enough to settle into oil andwater layers by the action of gravity


4 Motor driven pump of 410 m3/hr capacity work at 10kg/cm2 pressure.2 diesel engine driven pump of 410 m3/hr capacity work at 10 kg/cm2 pressure.

Jockey pumps are 2 in number which are motor driven and there capacity is 80 m3/hr.

Various potable fire extinguisher are present such as dry carbon, carbon dioxide.


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HEATER TREATER

CTF (Central Tank Farm)

GGS VII-KALOLINSTALLATION MANAGER - Mr. Ajay Ratan

DATE OF COMMISION: July- 1976


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PHYSICAL & CHEMICAL PROPERTIES

Ionic Nature- non-toxic

Viscosity at 300C- less than 100 poise

pH of 5% solution- 5.5 to 8.0

Solubility in H20- dispersible

Solubility in xylene & tolune- soluble

Flammability- inflammable

LABELLING, STORAGE & HANDLING

Storage conditions- store in cool, well- ventilated area

Disposal- incinerate in a furnace as per local state or national legislation

EMERGENCY MEASURES

Spillages- adsorb onto sand, earth or similar adsorbent material .Wash the spillage area.

FIRST AID

Skin contact- wash with water followed by soap & water

Eye contact- irrigate with clean water or an eye wash solution, obtain medical attention as

precaution. Inhalation- The affected person should be moved to fresh air & made to rest.

Ingestion- Give water or milk to drink.

3. TRIPLEX RECIPROCATING PUMP

Used for pumping oil from storage tank to discharge line to NAWAGAM

Maximum pressure- 64 Kg/cm2

Input- 86 KWPump RPM-260

Oil used for lubrication- 80L

Servo gear HP- 140It is motor driven pump

KW- 110

HP-150

RPM-1480

4. BOOSTER COMPRESSOR

Used to compress the gas which comes out from the separator vent at pressure 1.5 kg/cm2 to 4 5

kg/cm2 which is then send to GCS for further compression.

Make- Ingersoll rand

Model- 8.5 X 7 single stageCapacity- 10000m3/day

Suction pressure- 1.5 kg/cm2

Discharge pressure- 5 kg/cm2

5. POWER SUPPLY

Normal power is supplied from 11KV grid of the electric board

The overall normal requirement envisaged has been of the order of 100KVA


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Emergency power plant is maintained by 320KVA diesel generator whose power factor is0.8 andpower of engine is 396 HP

6. FIRE WATER SYSTEM

2 reservoir of water having capacity 120 m3 and 350 m3

respectively are available.

2 pumps are also present one is motor driven and second one diesel engine driven. Second one is

used as stand by.

Specifications of motor driven pump:

Capacity- 170 m3/hr

Discharge pressure- 6 Kg/cm2

Specifications of engine driven pump

Head- 100 m

Discharge rate- 171 m3/hr

Size- 100X 125 mm

Speed- 1800 RPM Pump input- 64.9 KW


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EFFLUENT TREATMENT PLANT (ETP)-II (KALOL)

INSTALLATION MANAGER- Mr. Ajay Ratan

DATE OF COMMISION - 05.07.1993RECEIVING STATUS: Effluent from

GGS- I (Kalol),

GGS-VII (Kalol),GGS-II (Kalol),

CTF-(Kalol) and to CTF effluent of GGS- IV also comes.

PRODUCTION- 1000 m3/day and 50 m3/day (max.) of oil.


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POWER CONSUMPTION - 19378 KW/day

OBJECTIVESThe main objective of this plant is to collect effluent from various GGS and CTF and treat that

water.

Finally the treated water is sent to water injection plant for final treatment.

PROCESS DESCRIPTION

Firstly effluent from various GGS (as mentioned above) comes into header of ETP and from thoseheaders it goes to hold up tank .Then it goes to equalization tank where effluent is allowed to stand

for some time. Thus because of this settling time water settles down and oil at the top. Then on

weekly basis oil from the top is sent to sludge separating tank as the content of oil in it isvery less.But water goes to receiving sump through centrifugal pump. Then from receiving sum pit goes to

flash mixer where alum and polyelectrolyte are added in 200 ppm and 10 ppm concentrations

respectively. Alum acts as coagulant & polyelectrolyte is added to separate further. Then from there

water goes to clariflocculator which has agitator inside the vessel. After agitation sludge settles downand after some time it is sent to sludge sump and then it is pumped to sludge

lagoons there sludge from sludge separating tank also comes and from there it is sent

for bioremediation. Now water which comes out of clariflocculator goes to clarified water tank andfrom there it is pumped into sand filters where the final filtration is done and then this water goes toconditioning tanks where again some settling time is given so that even if some amount of impurities

is there can settle down and finally the treated water goes to storing tank and from there it is pumped

into Cental Water Injection Plant (CWIP) through pipelines.

ETP FACILITIES

1. FLASH MIXERCapacity- 1.2 m3

Alum and poly electrolyte are added

2. CLARIFLOCCULATORCapacity-224 m3

Purpose- it helps in separation of water from oil.

It consists of huge cylindrical tank with a hollow cylinder inside. The solution of oil and water

enters through this hollow cylinder with oil on top. Oil separates at the top through V-notch providedat the sides (its periphery). Sludge settles down in a feet bottom and sludge is pumped through pump

to lagoon. Whereas water is transferred to storage tank-2 (SR-2) and from there water is sent to filter

for further purifications

3. PRESSURE FILTER

- 2.5 m3

Number- 2 Nos., but one filter is used at a time other is used as a standby.The filter consists of membrane made of sand and gravel (sizes ranges from 9mm-600mm).Water

is circulated here and all particles are filtered by them.

Back Wash Water arrangement is also made in order to clean the filter when its cleaning isrequired. This is done daily as two pressure filters are available, one is used at a time and other is

used as stand by.


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4. PUMPING SYSTEM

7 centrifugal pump

Capacity- 40 m3/hr

Head- 50 m

Speed- 1470 RPM

Input- 13KW

Efficiency- 41%

3 screw pump

Head- 30 m

RPM- 1200

HP- 1.5

SAND FILTER


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ETP (EFFLUENT TREATMENT PLANT) CENTRAL WATER INJECTION PLANT(CWIP)INSTALLATION MANAGER -Mr. Ajay Ratan

DATE OF COMMISION-04.04.1990


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UNIT PRODUCTION - 1680 m3/day

POWER CONSUMPTION - 20000 KW/month

DISCHARGE RATE- 35 m3/hr

CHEMICALS USED Sodium sulfide- 40 ppm Scale inhibitor- 20 ppm Corrosion inhibitor- 20ppm

PROCESS DESCRIPTION -Water from ETP through pipelines comes to CWIP for further chemical

treatment before it is sent to GGS for water injection. Water at 35-37 m3/hr of flow rate and atpressure of 4 kg/cm2 is pumped into CWIP through pipelines from ETP. Effluent enters the treated

water tank (600 m3) where tube well water is also added in fixed proportion. This tube well water

(raw water) is passed to three micro filters of 25micron,10 micron and 3 micron one by one and thenfinally it is sent to raw water hold tank. At the outlet of the tank three chemicals are added, sodium

sulphite (40 ppm) which acts as oxygen scavenger, corrosion inhibitor (20 ppm) is added to prevent

corrosion and scale inhibitor (20ppm) is also added to decrease precipitation formation. Now this

effluent is sent to treated water tank where water from ETP is mixed with it by mean of agitator. Thiseffluent is then pumped with the help of water injection pump to headers. Now from headers the

water is injected at high pressure and at low pressure through four inch pipe line. Water is injected at

high pressure of 60-62 kg/cm2 to 13 wells used for artificial lifting which are connected to GGS VII.Low pressure water is injected at 40-42 kg/cm2 connected to 28 wells used for artificial lifting. Here4 wells are connected to GGS I, 4 wells to GGS XI, 10 wells to GGS II and 10 wells are connected to

GGS VII. So total wells connected to CWIP is 52 wells.

CWIP FACILITIES

1. PUMPING SYSTEM

4 reciprocating pumps are available and out of which 2 are working and 2 are stand by.Specifications of pump are:

Capacity-35 m3/hr RPM-314

Maximum working pressure- 170 kg/cm2

BKW- 190.78

MOTOR

RPM-1455

HP/KW-322/240

Efficiency-95.5%

Volt-415

2. STORAGE SYSTEMBalancing tank- 200 m3Storage tank -600 m3

Treated water tank- 600 m3


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CWIP (CENTRAL WATER INJECTION PLANT)

CENTAL TANK FARM (CTF)NAWAGAMINSTALLATION MANAGER - Mr.B.K.Shit

AREA OF INSTALLATION - 100 AcresRECEIVING STATUS


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GGS- I, II, III500 m3/dayRamol, Nandej, Wasna fields- 800-900 m3/day

CTF Kalol- 8000 m3/dayMehsana fields- 8000 m3/day

STORAGE TANKS

8 tanks- 2000 m3

MAIN OBJECTIVE

As such in this installation no processing is done, they just pump desired crude oil to desalter plant

which has come from various CTF.

Every hour water content is checked in the samples of treated crude oil of desalter plantafterfulfilling the desired conditions of refineries dispatching is done from desalter to refineries .

They target to have water content of 0.5-1 % in oil before discharging.

PUMPING SYSTEMMake- BPCL

Type- Quintuplex plunger pump

Maximum discharge- 120 m3/hrMaximum operating pressure- 40 kg/cm2Rate BHP- 430 HP

MOTOR

HP- 545

KW-400

RPM-1450

Voltage-415

Frequency- 50 Hz

Current- 676 Amp

DESALTER PLANT: NAWAGAMINSTALLATION MANAGER : Mr. B.K. Shit

DATE OF COMMISION : 01.01.1995PLANT CAPACITY : 6.7 million metric tons per year

NUMBER OF TRAINS (UNIT) - 3 trains of 2.23 million metric tons per year (2 trains are operating

and 1 is stand by)

RECEIVING STATUS

Crude oil from

Mehsana Ahmedabad Assest

FEED STOCK CHARACTERSTICS

Chloride in oil feed water: 45oo ppmChlorides as Cl salt- 81 ptbSpecific gravity of oil-0.8948Totalsulphur, %wt- 0.007Wax content,%wt-6.8Total acidity, mg KOH/gm- 4.65

DESALTED CRUDE OIL CHARACTERSTICS

Salt content-10-15 ptb

PROCESS DESCRIPTION

Crude oil is received from the existing tank farm to new tanks through a 30 suction header. 4Nos.feed pumps are installed for pumping feed to desalter to three trains whereas the fourthpump is

common stand by for all the three trains. Demulsifier chemical is mixed with the feedcrude oil in the

suction line in the feed pump. Crude oil from the feed pump is further mixedwith wash water at a rate


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of approximately 0.5 % of the crude before the crude is sent through heat exchanger. In this heatexchanger the feed is heated to about 63

0C by exchanging heat with the outgoing treated crude oil

from the desalter. Treated crude passes through the tube side of the heat exchangers. The crude fromthe exchangers will pass through the feed heater where in the temperature is raised to 100 0C before

entering the desalter vessel. In the desalter vessel feed crude is fed at lower portion of vessel where in

it travels and separates through electrostatic grid. The electrostatic grid aids the breaking of emulsion

and settlement of water at the bottom. The crude after losing water/salts will be let out through thecrude outlet line from the top of vessel. Desalter has bottom outlet connections at intervals for

removal of water and sediments settled atbottom of desalter. Part of the produced water is circulated

back into desalter vessel through desludging pump (rated at 50 m3/hr and 25 m head) to maintain thewater phase in the desalter in a fluidized conditions so that the sediments settle down at the bottom of

the vessel and form the thick mud.The desalter vessel is provided with sampling valves at various

elevations to collect and analyse the samples at various elevations on the desalter vessel. So byanalyzing these samples discharging is done.

NAWAGAM PLANT FACILITIES1. Storage system

Crude oil

No. of tanks: 4

Type: floating roof

Capacity:30,000 m3

Water

Raw water tank:2

Type: cone roof

Capacity: 700 m3 each

2. POWER SUPPLY SYSTEM

Distribution voltage:415 voltsNormal power: 240 volts, AC

Shut down: 110 volts, DC

Fire alarm system: 240 volts AC


2 JOCKEY pump:

Working pressure: 8 kg/ cm2

Feed rate: 10 m3/hr

2 diesel engine driven pump

Feed rate: 410 m3/hr1 electrical driven pump

Feed rate: 410 m3/hr

2 water storing pond are there of capacity 3200 m3 each

4. PUMPING SYSTEM

Rotating pump Quantity Type Capacity(m3/hr) Head(m)

Desalter feed pump 4 Centrifugal 330 140

Service water pump 2 Centrifugal 40 50

Process water pump 2 Centrifugal 40 135

Desludging pump 2 Centrifugal 50 25

Drinking water pump 2 Centrifugal 5 25


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Injectionpumps(reciprocating)

4 Centrifugal 700 lpm 29.7

5. COMPRESSORS

Air compressor

Quantity: 2

Capacity:350 Nm3/hr

Discharge pressure: 9kg/cm2

6. BURNERSNo. of burners: four reactor

Type of burner: forced draft

Type of fuel: natural gasHeat liberation(max) (mm BTU/hr): 8

7. MISCILLANEOUS

Instrumental Air Dryer:

Quantity: 2

Capacity: 150 m3/hr

Demulisifier mixer

Quantity: 2


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WWTP-WASTE WATER TREATMENT PLANTThis plant is the part of DESALTER PLANT as the treated crude oil is sent to refineries buteffluent is

sent to WWTP for chemical treatment.


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WWTP FACILITIES1. WASH TANKNumber of units- 2

Capacity- 1000 m3Storage temperature- 600C

Water from desalter plant is stored in these wash tanks, after filling of one wash tank tothe desired

level, valve of 2nd

wash tank is opened and 1st

tank is taken into consideration.

2. TPI (TILTED PLATE INTERCEPTOR) SEPARATOR

The effluent from wash tank is routed to TPI. The TPI consists of 3 bays each having one platespack.

It has one inclined plate at 450, depth of third bay is largest, the oily sludge is collected atthe hopper

is discharged into wet sump by gravity. So here the primary separation takes place.

3. FLASH MIXERNumber of unit- 1

Capacity-4.25 m3

Alum- 50 ppm

Waste water after removal of free oil in TPI flows by gravity into flash mixer where alumis addedas coagulant. A suitable agitator is provided to mix alum solution with the waste water. Suitable MS

ladder and MS rungs epoxy painted are provided in the system for approach and maintenance.

4. FLOCULATORType- paddle type

Chemical addedpolyelectrolyte

Volume of unit- 7 m3

DISSOLVED AIR FLOATATION UNIT (DAF)

The DAF unit is carbon steel epoxy painted construction fitted with flocculator. The effluentwaterafter getting dosed with alum in the flash mixer flows by gravity into the DAF unit. The already

coagulated effluent is added with deoiling type polyelectrolyte in the flocculation unit before DAF

chamber. Floatation of solids is accomplished by introduction of millions ofmicroscopic air bubble. As these bubbles rise they attach themselves to the particles in thesuspension

and carry them to the surface for removal. An important principle of DAF system is the introduction

of air in the recirculation effluent and blending the raw flow where the millions of microscopicbubbles are found to which the suspended particles get attached and lift to the surface removal. A

skimming arrangement is provided at the top to remove the floatation sludge blanket and this scum is

routed to oily sludge sump and from the bottom water goes to receiving sump and from there it is

discharged.

5. TREATED EFFLUENT SUMP

The treated effluent from DAF is routed by gravity to the treated effluent sump. Arrangements

should be made to pump the treated water to depleted pump.Number of unit- 1

Material of construction- RCC

Effective capacity- 50 m3Detention time- 0.25 hrs

6. OIL SLUDGE SUMP AND PUMP HOUSEThe oil sludge generated during treatment in TPI and DAF units flows by gravity to oilsludge from

there it is pumped to sludge thickener for thickening.

Number of unit- 1


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Material of construction- RCCEffective capacity- 6.75 m3

Detention time- 1hrNumber of pumps provided- 2

Type- horizontal, centrifugal

Capacity- 10 m3/hr

Installed HP of drive- 3

7. THICKNER

Thickening is the unit process which is employed for thickening of the sludge to increase thesludgecontent in the sludge. The stream entering the thickener is sludge from oily sludge sump.Here

agitation is done and after that settling time is given so that sludge can settle at bottom andoil is sent

to wet slop from the top.Number of unit- 1

Material of construction- RCC

Effective capacity- 85 m3

Detention time- 1hr

PROCESS DESCRIPTION

Effluent from the desalter through pipelines is pumped into wash tanks and from there issent to TPIand then it is sent to flash mixer where alum is added. Then the effluent by gravityflows to DAF andoil to oil sludge. In DAF polyelectrolyte is added

And finally the effluent is sent to receiving sump and oil is sent to oil sludge and fromthere it is

sent to thickner and then sent back to desalter.


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the well bore to cause the well to flow into the production facilities at the surface .In other wells,natural energy will not drive oil to the surface in sufficient volume. The reservoirs natural energy

must then be supplemented by some form of ARTIFICIALLIFT.Types of Artificial Lift Systems

There are four basic ways of producing an oil well by artificial lift. There are.(1) Gas Lift.(2) Sucker

Red Pumping.(3) Submersible Electrical Pumping.(4) Subsurface Hydraulic Pumping.(5) Screw

pump (pc pump).Choosing an Artificial Lift System

The choice of an artificial lift system in a given well depends upon a number of factors. Primary

among them, as far as gas lift is concerned is the availability of gas. Then gas lift is usually an idealselection of artificial lift.

The Process of Gas Lift

Gas Lift is the form of artificial lift that most closely resembles the natural flow process. It can beconsidered an extension of the natural flow process. In a natural flow well, as the fluid travels upward

towards the surface, the fluid column pressure is reduced and gas comes out of solution. The free gas

being lighter then the oil it displaces, reduce the weight of the fluid column above the formation. This

reduction in the fluid column weight produces the pressure differential between the well bore and thereservoir that causes the well to flow. When a well makes water and the amount of free gas in the

column is reduced the same pressure differential between the well bore and reservoir can be

maintained by supplementing the formation gas with injected gas.Types of Gas LiftThere are two basic types of gas lift systems used in the oil industry. These are:(1) Continuous

flow(2) Intermittent flow

Continuous Flow Gas Lift:In the continuous flow gas Lift process, relatively high pressure gas is injected down hole into the

fluid column. This injected gas joins the formation gas to lift the fluid to the surface by one or more

of the following processes.1. Reduction of the fluid density and the column weight so that the

pressure differential between the reservoir and the well bore will be increased.2. Expansion of theinjection gas so that it pushes ahead of it which further reduces the column weight thereby increasing

the differential between the reservoir and the well bore.3. Displacement of liquid slugs by large

bubbles of gas acting as pistons.Intermittent Flow Gas Lift:

If a well has a low reservoir pressure or every low producing rater it can be produced by a form of gas

lift called intermittent flow. As its name implies this system produces intermittently or irregularly andis designed to produce at the actual rate at which fluid enters the well bore from the formation. In the

intermittent flow system, fluid is allowed to accumulate and build up in the tubing at the bottom of

the well. Periodically, a large bubble of high pressure gas is injected into the tubing very quickly

underneath the column of liquid and liquid column is pushed rapidly up the tubing to the surface. Theaction is similar to firing a bullet from a rifle by the expansion of gas behind the rifle slug. The

frequently of gas injection in intermittent lift is determined by the amount of time required for a

liquid slug to enter the tubing. The length the gas injection period will depend upon the time required

push one slug of liquid to the surface.Advantages of Gas Lift

1) Initial cost of down hole equipment is usually low.2) Gas lift installations can be designed to lift

from one to many thousand of barrels.3) The producing rate can be controlled at the surface.4) Sandin the produced fluid does not affect gas lift equipment is most installation.5) Gas lift is suitable for

deviated well.6) Long service lift compared to other forms of artificial lift.7) Operating costs are

relatively low.8) Gas lift is ideally suited to supplement formation gas for the purpose of artificiallylifting wells where moderate amount of gas are present in the produced fluid.

9) The major items of equipment (the gas compressor) in a gas lift system are installed onthe surface

where it can be easily inspected, repaired and maintained.


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Limitations1. Gas must be available. Natural gas is quite cheap as compared to air, exhaust gases

andnitrogen.2. Wide well spacing may limit the use of a centrally located source of highpercentage.3. Corrosive gas lift can increase the cost of gas lift operations if it is necessary to

treat or dry the gas before use.


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SUCKER ROD PUMPING

80-90% of all artificial lift wells are being produced on sucker rod pumping; the most common is the

beam pumping system. Sucker Rod Pumping System is time tested technological marvel which has

retained its typical features for over a century. When oil well ceases to flow with own pressure, this

Artificial Lift system is installed for pumping out well fluid. In the well bore reciprocating pumpcalled Subsurface pump is lowered which is operated by surface system called SRP surface unit or

Pumping unit. Prototype of one such unit is in action here.

General considerations:Oil will pumping methods can be divided into two main groups: Rod System: Those in which the

motion of the subsurface pumping equipment, originates at the surface and is transmitted to the pump

by means of a rod string. Rod-less System: Those in which the pumping motion of the subsurfacepump is produce by means other than sucker rods. Of these two groups, the first is represented by the

beam pumping system and the second is represented by hydraulic and centrifugal pumping systems.

The beam pumping system consists essentially of five parts (1) The subsurface sucker rod driven

pump.(2) The sucker rod string which transmits the surface pumping motion and power to thesubsurface pump.(3) The surface pumping equipment which charges relating motion of the prime

motion of the prime mover into oscillating linear pumping motion.(4) The power transmission unit or

speed reducer (5) The prime mover which furnishes the necessary power to the system.

a report of training ongc

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