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Tishk International UniversityEngineering FacultyPetroleum and Mining Department

Petroleum Production Engineering I

4-Grade- Fall Semester 2021-2022

Lecture 2: Production Systems

Instructor: Frzan AliFrzan Ali Petroleum Production

Engineering I

• Production Engineering:

Part of petroleum engineering which attempts to maximize production in a cost-effective manner.

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Introduction

A sketch of a petroleum production system Frzan Ali 3

A typical hydrocarbon phase diagram

0 50 150 200 250 300 350100

1000

500

1500

2000

2500

3000

3500

4000

Reservoir Temperature (oF)

Rese

rvoir P

ress

ure

(psi

a)

Liquid Volum

e40%

20%

10%

80%

5% 0%

Bubble Point

Gas ReservoirsRetrograde

Condensate

Reservoirs

Critical

Point

pi, T

ptf, Ttf

pwf, Twf

Dew Point

Cri

condenth

erm

Poin

tFrzan Ali 4

Gas Oil Ratio - GOR

•Wells in the same reservoir can fall into categories of oil, condensate, and gas wells depending on the producing GOR (gas oil ratio)

•SCF: Standard Cubic Feet. STB: Stock Tank Barrel

• Gas well: GOR>100K scf/stb• Gas condensate: 5K<GOR<100K scf/stb• Oil well: GOR<5K

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Drive Mechanisms

Oil reservoirs can be classified based on boundary type

which determines driving mechanism:

(1) Water-drive reservoir

(2) Gas-cap drive reservoir

(3) Dissolved-gas drive reservoir.

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Oil

Water

WOC

A sketch of a water drive reservoir

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Edge-water drive advantage:

• Reservoir pressure can remain in its initial value above bubble-point

pressure

• steady-state flow can be remained for a long time before water break

through

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Gas Cap

Oil

A sketch of a gas-cap drive

reservoir

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A sketch of a dissolved-gas drive reservoir

Oil and Gas

Reservoir

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A sketch of a typical flowing oil well

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A sketch of a wellhead

Choke

Wing Valve

Master Valve

Tubing Pressure Gauge

Flow Fitting

Tubing

Intermediate Casing

Surface CasingLowermost Casing Head

Uppermost Casing Head

Casing Valve

Casing Pressure Gauge

Production Casing

Tubing head

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A sketch of a casing head

Bowl

Production

Casing

Casing

Head

Surface

Casing

Casing Hanger

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A sketch of a tubing head

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A sketch of a Christmas tree

Choke Wing Valve Wing Valve Choke

Master Valve

Tubing Head Adapter

Swabbing Valve

Top connection

Gauge Valve

Flow Fitting

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Sketch of a surface valve

16

A sketch of a wellhead choke

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The procedures to open a well:

(1) The master valve is barely open (cracked). Escaping fluid makes a hissing sound. When the fluid no longer hisses through the valve, the pressure has been equalized. Then the master valve is opened wide.

(2) If there are no oil leaks the operator cracks the next downstream valve that is closed. Usually this will be either the second (backup) master valve or a wing valve. Again, when the hissing sound stops the valve is opened wide.

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(3) Open other downstream valves the same way.

(4) To read the tubing pressure gauge, the operator must open the needle valve at the top of the Christmas tree. After reading and recording the pressure, the operator may close the valve again to protect the gauge.

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The procedures to open a well:

Conventional horizontal separator

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Double action piston pump

Suction Suction

Discharge Discharge

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Elements of a typical reciprocating compressor Frzan Ali 22

The major objective of the safety system is toprevent the release of hydrocarbons from theprocess and to minimize the adverse effects ofsuch releases if they occur. This can be achievedby

(1) preventing undesirable events(2) shutting-in the process(3) recovering released fluids(4) preventing ignition

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Safety System

The modes of safety system operation

Include:

a. Automatic monitoring by sensors

b. Automatic protective action

c. Emergency shut-down

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Protection concepts and safety analysis are based

on undesirable events which include

A. Overpressure caused by1. increased input flow due to upstream flow control device

failure

2. decreased output flow due to blockage

3. heating of closed system

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B. Leak caused by1. corrosion2. erosion3. mechanical failure due to temperature change, over- and under-pressure, and

external impact force

C. Liquid overflow caused by1. increased input flow due to upstream flow control device

failure

2. decreased output flow due to blockage in the liquid discharge

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Protection concepts and safety analysis are based

on undesirable events which include

D. Gas blowby caused by1. increased input flow due to upstream flow control device failure2. decreased output flow due to blockage in the gas discharge

E. Under-pressure caused by1. outlet flow control device (e.g., choke) failure

2. inlet blockage

3. cooling of closed system

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Protection concepts and safety analysis are based

on undesirable events which include

F. Excess temperature caused by

1. over-fueling of burner

2. external fire

3. spark emission

Process and Instrumentation Diagrams (P&ID)

Frzan Ali Petroleum Production

Engineering I28

P&ID is a detailed diagram in the process industry which shows the piping

and process equipment together with the instrumentation and control devices.

Flow Safety

Valve

FSV

Burner Safety

Low

BSL

Pressure Safety

High & Low

PSHL

Pressure Safety

Element

PSE

Flow Safety

High

FSH

Flow Safety

Low

FSL

Pressure Safety Valve

PSVPSV

Level Safety

Low

LSLLSH

Level Safety

High

Temperature

Safety High

TSH TSL

Temperature

Safety Low

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P&ID Symbols

Level Safety

High & Low

LSHL

Flow Safety

High & Low

FSHL

Temperature

Safety

High & Low

TSHL

Temperature

Safety Element

TSE

Pressure

Safety High

PSH

Pressure

Safety Low

PSL

Surface Safety Valve

SSV SSV

Underwater Safety Valve

USV USV

Blow Down Valve

BDV BDV

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P&ID Symbols

MAWP > SITP

<10’

(3M)

TSE

SSV

PSHL FSV

Outlet

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P&ID Symbols

Safety system designs for underwater wellhead flow lines

MAWP > SITP

USV

Outlet

PSHL FSV

MAWP > SITP

USV

Outlet

FSVPSHL

Denotes platform limits

PSL SDV

Option 1

Option 2

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P&ID Symbols

Safety system design for pressure vessel

PSHL

PSV

Gas outlet

FSV

Gas makeup systemTSE

Inlet

LSL

LSH

FSV

Oil outlet

Pressure

Vessel

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P&ID Symbols

Safety system design for pipeline pumps

PSV

TSE

PSHL

FSV

SDV

Discharge

PumpFrom storage

component

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P&ID Symbols