BASIC PETROLEUM AND ESP Andi A Wibowo,

SBU Production Supervisor

BASIC PRODUCTION-ESP OPERATION

CONTENTS

HOW HYDROCARBON FORMED?HOW HYDROCARBON FORMED?

OIL FIELD RESERVOIR OIL FIELD RESERVOIR

RESERVOIR DRIVE MECHANISMRESERVOIR DRIVE MECHANISM

RESERVOIR CHARATERISTICRESERVOIR CHARATERISTIC

RESERVOIR PRESSURE PROFILERESERVOIR PRESSURE PROFILE

TYPICAL COMPLETION TYPETYPICAL COMPLETION TYPE

FORMATION PROBLEMFORMATION PROBLEM

SCALESCALE

BASIC ESPBASIC ESP

HOW HYDROCARBON FORMED?

I I I I I I I I I I I I I I I I I I I I I I

I I I I I I I I I I I I I I I I I I I I I I

I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

I I I I I I I I I I I I I I I I I I I I I

DUST

DEAD FISH

TEMPERATURE

PRESSURE

SALINE

TEMPERATURE

TEMPERATURE

PRESSURETEMPERATURE

PRESSURETEMPERATURE

PRESSURE PRESSURETEMPERATURE5000 Ft – 21000 Ft5000 Ft – 21000 Ft5000 Ft – 21000 Ft5000 Ft – 21000 Ft

+3,000,000 Years

TRANSFORM TO HYDROCARBON

SEDIMENTATION

SE

DIM

EN

TA

TIO

N K

EE

PS

OC

CU

RIN

G O

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IME

HOW HYDROCARBON FORMED??

Oil formed at 120°F- 350 °F, in 5,000 – 21,000 feet depth about 3,000,000 years ago (minimum).

• Gas formed at temperature > 350 °F, in 21000 feet depth in short period of time

• Due to smaller density, buoyancy forces and capillarity ,oil and gas move up through the area – this is called fluid migration

• Vertical migration for gas and oil sometimes possible to surface

• Horizontal migration less than 200 miles of distance

• Hydrocarbons are trapped and accumulate on the impermeable rock media which is common called Cap Rock

HOW HYDROCARBON FORMED??

TRAP

200 MILES

SURFACE

UNSEALED ROCK

SALINEIMPERMEABLE

ROCK

OIL RESERVOIR

MIGRATION

TRAPPED

HYDROCARBON

OILFIELD RESERVOIR

A petroleum reservoir must A petroleum reservoir must have three things:have three things:

- Source Rock for the Hydrocarbons

- Reservoir rock that is porous and permeable

- An Impermeable seal to trap the Hydrocarbon

• Reservoir rock generally sedimentary of sand stone or limestone (carbonate)

• Talang Akar formation is a sandstone and Baturaja formation is Carbonate

Pore space

Permeability

OILFIELD RESERVOIR

Productivity Index (PI) = Q / (SBHP-PBHP)Productivity Index (PI) = Q / (SBHP-PBHP)

PI PI Rate Rate So Bigger PI is better So Bigger PI is better

PI depends on : - drawdown (SBHP – PBHP)PI depends on : - drawdown (SBHP – PBHP)

- reservoir permeability (k) - reservoir permeability (k)

- Porosity- Porosity

How fluid goes to surface?How fluid goes to surface?

- Natural flow : if Reservoir pressure still high - Natural flow : if Reservoir pressure still high

- Artificial lift :if reservoir Pres has been depleted- Artificial lift :if reservoir Pres has been depleted

How about CNOOC ? “ Almost all wells using ESP as How about CNOOC ? “ Almost all wells using ESP as artificial lift”artificial lift”

RESERVOIR DRIVE MECHANISM

Water DriveWater Drive

Solution Gas DriveSolution Gas Drive

Gas- Cap expansion driveGas- Cap expansion drive

RESERVOIR CHARATERISTIC

Porosity : comparison between pore volume and Porosity : comparison between pore volume and bulk volume (space of formation rock)bulk volume (space of formation rock)

Permeability. Higher permeability is better reservoirPermeability. Higher permeability is better reservoir

Fluid Saturation, represent percent of pore volume Fluid Saturation, represent percent of pore volume that filled by fluidthat filled by fluid

Formation Volume Factor, represents the shrinkage Formation Volume Factor, represents the shrinkage of res.fluid volume when it at surface conditionof res.fluid volume when it at surface condition

o

oo

E.S.P.

PSI

SBHP *

PBHP *

Pressure

Distance

Qf

PI = PI = Qf . Qf .

(SBHP-PBHP)(SBHP-PBHP)

Near wellbore drawdown about 70%Near wellbore drawdown about 70%

SBHP* and PBHP* read with Surveyor UnitSBHP* and PBHP* read with Surveyor UnitFluid

Level

RESERVOIR PRESSURE PROFILE

WELL COMPLETION

FORMATION PROBLEMS

Pressure Depleted Pressure Depleted

‘ ‘The pressure is naturally depleted along with The pressure is naturally depleted along with oil producing’, Low reservoir pressure ==oil producing’, Low reservoir pressure == more difficult to lift up ==more difficult to lift up == need artificial lift. need artificial lift.

Formation problem / Inflow Problem Formation problem / Inflow Problem

- Scale Problem- Scale Problem

- Sand Problem- Sand Problem

SCALE PROBLEM

Scale is a mineral precipitation, It could be a problem Scale is a mineral precipitation, It could be a problem if in a big amount and plugging up reservoir pore if in a big amount and plugging up reservoir pore and pump.and pump.

Very common oil field scale : Very common oil field scale : calcite,barite,ironic,anhydrite,gypsum,etccalcite,barite,ironic,anhydrite,gypsum,etc

Why scale build up? The main cause is decreasing Why scale build up? The main cause is decreasing mineral (calcite, barite,etc ) solubility in the water by mineral (calcite, barite,etc ) solubility in the water by changing temperature and pressure.changing temperature and pressure.

Generally, The solubility will decreasing when P and Generally, The solubility will decreasing when P and T drop. T drop.

SCALE PROBLEM (CON’T)

Scale deposit in the impeller,diffuser and tubing

SCALE PROBLEM

Scale could lead to:Scale could lead to:

- Inflow problemInflow problem : scale could plugging up the : scale could plugging up the formation,perforation and pump intakeformation,perforation and pump intake

Indication : BHP rapidly decreasing, Running Indication : BHP rapidly decreasing, Running ampere drop and BHT increasing due to not enough ampere drop and BHT increasing due to not enough fluid cooling down the ESP motorfluid cooling down the ESP motor

- Pump stuckPump stuck = = Overload = Overload = DHP DHP

SCALE PROBLEM

What should be done?What should be done?

- Stimulation, If scale build up in formation.Stimulation, If scale build up in formation.

Stimulation is the process of injection acid into formation to remove Stimulation is the process of injection acid into formation to remove damage around wellbore.damage around wellbore.

- Pump clean up,If scale build up in pump.Pump clean up,If scale build up in pump.

Stimulation Process

Basic ESP

Basically ESP is a centrifugal pump with electric power Basically ESP is a centrifugal pump with electric power from surface.from surface.

ESP part : surveyor+ motor+ Protector+ Intake+ PumpESP part : surveyor+ motor+ Protector+ Intake+ Pump

ESP develops extra head (pressure) to lift fluid to surface. ESP develops extra head (pressure) to lift fluid to surface.

The pump sizing and design depends on PI,free gas ,sand The pump sizing and design depends on PI,free gas ,sand tendencies,depth,viscosity,etctendencies,depth,viscosity,etc

Each type of ESP has optimum operating range and Each type of ESP has optimum operating range and efficiency.efficiency.

ESP isn’t efficient for high free gas well ESP isn’t efficient for high free gas well gas lock gas lock problemproblem

ESP manufacture : ESP manufacture : REDA,Centrilift,ESP,ODI,Daqing,Shangli,etcREDA,Centrilift,ESP,ODI,Daqing,Shangli,etc

E le c tric M o to rE le c tric M o to r

Protector

Intake or Gas Separator

Centrifugal Pump

System Components of Typical Installation

The pump is seated above the perforations in such a way that the well fluid moves upward around the motor housing, cooling the motor by dissipating the heat generated.

All the components are connected together and hang from the tubing.

CableMLE and Power Cable

Basic ESP Components

Basic ESP EngineeringS

ch

lum

berg

er P

rivate

Flow

FlowFlow

Ground Level

Producing Fluid Level

Pump Set Depth

Wellhead

Net Vertical Lift1

2Total Friction Loss

Wellhead Pressure

3

Pump Operating Range

Efficiency

Pump Range

Head

HP per Stage

ESP Problems

How to identify problem? Simple….LOOK AMCHART. How to identify problem? Simple….LOOK AMCHART. Every single line tell us something.Every single line tell us something.

What is am chart?.What is am chart?.

- Electrical drive pump. - Electrical drive pump.

- Power consumed by motor depends on operating point ==>- Power consumed by motor depends on operating point ==>

pump curvespump curves

- Power consumed = f(running amps)- Power consumed = f(running amps)

- Running Amps ==> diagnose parameter- Running Amps ==> diagnose parameter

Commons Problem : Underload,Overload,Gas lock,Pump Commons Problem : Underload,Overload,Gas lock,Pump Off, lost flowOff, lost flow..

Underload Problem

Why it happen?Why it happen?

Not enough fluid Not enough fluid level, shaft brokenlevel, shaft broken

Troubleshooting:Troubleshooting:

Choke backChoke back

Reduce frequencyReduce frequency

Try to raise up fluid Try to raise up fluid level by bleed off level by bleed off casing pressurecasing pressure

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M I D N I G H T

Under-current Load

Overload Problem

Common causes:Common causes:

Increased fluid gravityIncreased fluid gravity

Sand productionSand production

Scale build upScale build up

Increasing viscosity Increasing viscosity (emulsion)(emulsion)

Electrical problemElectrical problem

DO NOT restart the DO NOT restart the pump before check pump before check cable and cleared cable and cleared problemproblem

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Overload

Gas Lock

Why? A big free gas in pump.Why? A big free gas in pump.

What we can do:What we can do:

Choke back and raise up Choke back and raise up fluid level at annulus.fluid level at annulus.

Reduce frequency using VSDReduce frequency using VSD

Deepening the pump Deepening the pump

Install down hole gas Install down hole gas separator (VGSA + AGH)separator (VGSA + AGH)

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Gas Locking

Pump hasgas locked

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