drilling for oil and gas

Drilling Drilling for Oil and Gasfor Oil and Gas

Moshtak OthmanPetroleum Resource ManagerMinerals and Energy Group

November 2004

Why we drill for oil & gasWhy we drill for oil & gas

Types of wells & drilling rigsTypes of wells & drilling rigs

Drilling techniquesDrilling techniques

Testing a new oil/gas fieldTesting a new oil/gas field

SummarySummary

WellsTwo main reasons for drilling a well:1 Exploration purposes - to confirm

the contents of a reservoir rockExploration is all about information

2 Appraisal / development purposes -to create a pathway through which the hydrocarbons can reach the surface

Seismic Vessel acquiring data about the structure of the formation below the seabedAir gun

Hydro phones6 km

Before we start drilling, we have to know where to drill

Marine Seismic Survey (offshore)

Land Seismic Survey onshore

Communication

Before we start drilling we have Before we start drilling we have 5 main problems to solve5 main problems to solve

1. We have to loosen the rock1. We have to loosen the rock

2. We have to remove the rock2. We have to remove the rock

3. We have to prevent the hole collapsing3. We have to prevent the hole collapsing

4. We have to prevent water, oil or gas blowing out4. We have to prevent water, oil or gas blowing out

5. We have to do all this safely and without harm 5. We have to do all this safely and without harm to the environment to the environment

Bit

Collars (thicker, heavier pipe)

Drill pipeThe rotary drilling method

cuttings

Polycrystalline Diamond Compact (PDC) Bits

Steel body

Tungsten stock

Polycrystalline Diamond Compact (PDC) Wafer 1/2 mm thick

Rotation

Tri -cone rock bit (with jets)


1. We have to loosen the rock 1. We have to loosen the rock





Stuck in the holeStuck in the hole(very bad)(very bad)

The rotary drilling method

Pump water (or Pump water (or muddy water) down muddy water) down the inside of the drill the inside of the drill

pipepipe

UnstuckUnstuck(very good)(very good)

Hole CleanHole Clean(even better!)(even better!)

MUD CIRCULATING SYSTEM

MUD DOWN THE DRILLSTRING

CUTTINGS & MUD UP THE ANNULUS

Source: Speaking of Oil & Gas - BHPP

CUTTINGS FILTERED OUT

CLEAN MUD PUMPED UP STANDPIPE

Invaded zoneInvaded zone

MUD:Basically water containing 10% microscopic clay particles [Bentonite] 5 - 2 microns platelets

WALL CAKEAlso known as:Mud cakeFilter cake

Hydrostatic pressure of the mud column presses against the mud cake helping to support the bore hole

Rig Components

Power

Support structure:derrick and sub base

Hoisting system:draw works, blocks and hook

Rotary system:swivel, top drive electric motor and drain pipe

Mud tankpump Mud tankCirculation system:mud tank, pump, hose,return flowline, shale shaker

TYPES OF DRILLING RIGSOFFSHORE

Bottom (sea floor) supported Floating vessels

Source: UK Offshore Operators Association

Category: Bottom supportedType: JACK-UPS

Category: FloatingType: SEMI-SUBMERSIBLES

FloatingType: DRILL SHIP

Dynamic Positioning

Computer controlled thrusterskeep the ship in one spot without using anchors.

Gas

oil

water

Multi purpose (AHTS) vessel towing a semi submersible drilling rigAHTS = Anchor Handling, Tow, Supply vessel

DIRECTIONAL DRILLING

Graphic: Sperry-Sun

Semi submersible rig with conventional mooring system

Anchor chain

Guide wires

Guide base

About as thick as your arm

Gas

oil

water

Guide base and guide wires

Phases of a well

1. Spud in2. Drill ahead

Gas

oil

water

MUD TANK

Phases of a well

1. Spud in2. Drill ahead3. Drill to first casing seat

Gas

oil

water

MUD TANK

Geologist

Phases of a well

1. Spud in2. Drill ahead3. Drill to first casing seat4. Pull out of hole (trip)

Gas

oil

water

MUD TANK

Hard YakkaHard Yakka

ROUGHNECKS

Top drive system

Phases of a well

1. Spud in2. Drill ahead3. Drill to first casing seat4. Pull out of hole (trip)5. Run first casing

Gas

oil

water

MUD TANK

liquid cement

Phases of a well

1. Spud in2. Drill ahead3. Drill to first casing seat4. Pull out of hole (trip)5. Run first casing6. Pump cement

Gas

oil

water

MUD TANK

Phases of a well

1. Spud in2. Drill ahead3. Drill to first casing seat4. Pull out of hole (trip)5. Run first casing6. Pump cement7. Displace cement behind casing

Gas

oil

water

MUD TANK

Phases of a well

1. Spud in2. Drill ahead3. Drill to first casing seat4. Pull out of hole (trip)5. Run first casing6. Pump cement7. Displace cement behind casing8. Drill ahead to 2nd casing seat

Gas

oil

water

MUD TANK

Phases of a well

1. Spud in2. Drill ahead3. Drill to first casing seat4. Pull out of hole (trip)5. Run first casing6. Pump cement7. Displace cement behind casing8. Drill ahead to 2nd casing seat9. Run 2nd casing string

Gas

oil

water

MUD TANK

Phases of a well

1. Spud in2. Drill ahead3. Drill to first casing seat4. Pull out of hole (trip)5. Run first casing6. Pump cement7. Displace cement behind casing8. Drill ahead to 2nd casing seat9. Run 2nd casing string10. Pump and displace cement

behind casing and installBlow Out Preventer (BOP)

Gas

oil

water

MUD TANK

Pipe rams (seals around drill pipe)

Blind/shear rams (cuts through drill pipe and seals against itself)

Blow Out PreventersBlow Out Preventers

Pipe rams (seals around drill pipe)Pipe rams (seals around drill pipe)

Blind/shear rams Blind/shear rams (cuts through drill pipe and seals against itself)(cuts through drill pipe and seals against itself)

Blow Out PreventersBlow Out Preventers

Gas

oil

water

Phases of a well



11. Drill ahead checking the mud forsigns of gas (weight up the mud)

Gas

oil

water

MUD TANK

Phases of a well



11. Drill ahead checking the mud forsigns of gas (weight up the mud)

Gas

oil

water

MUD TANK

14,000 Kpa

1 metre

Pressure = density x height x 9.81

Pressure = 1 kg/liter x 1 metre x 9.81 = 9.81 (kilopascals)

9.81

Water(density = 1 kg/liter)

1 metre


Pressure = 13.6 kg/liter x 1 metre x 9.81 = 133.4 (kilopascals)

133.4

Suppose it was Mercury(density = 13.6 kg/liter)

1 metre


Cant use Mercury, but we can add highly dense mineral powder called Barite (a.k.a Barytes)density 4.2 kg/ litre

Depending on how much we add, We can adjust the overall density of the mud

Suppose we add just enough to raise the density of the mud to 1.5 kg/litre

Pressure = 1.5 kg/litre x 1 metre x 9.81 = 14.7 (kilopascals)

14.7

Suppose my column is 1000 metres high, the pressure now would be 14,700 Kpa

Phases of a well



11. Drill ahead checking the mud forsigns of oil or gas

12. Drill through the reservoir to TOTAL DEPTH (TD)

Gas

oil

water

MUD TANK

1000 m

14,700 Kpa

14,000 Kpa





4. We have to prevent water, oil or gas 4. We have to prevent water, oil or gas blowing outblowing out


Phases of a well





Gas

oil

water

MUD TANK

1000 m

14,700 Kpa

Core Head

NOTE Artificial Diamond cutters

Core AnalysisCore Analysis

DRILL CORE SAMPLES

Phases of a well





13. POOH

Gas

oil

water

MUD TANK

CASING

Loading 30 inch conductor pipe onto a semi trailer at Darwin Supply Base

Well LoggingWell LoggingLogging Tools are sophisticated electronic tools.Logging Tools are sophisticated electronic tools.

They are lowered in the well to measure different They are lowered in the well to measure different natural properties of the rocks.natural properties of the rocks.

Analysing the combined response of differentAnalysing the combined response of differentelectronic tools can tell us a lot.electronic tools can tell us a lot.

The Expensive TruckThe Expensive Truck

Phases of a well




12. Drill to TOTAL DEPTH (TD)13. POOH, and run electric logs

Gas

oil

water

MUD TANK

WIRELINE LOGGING

Logging tools

Source: UK Offshore Oil & Gas

Electric Logging

Dip metreDip metre

Well EvaluationWell Evaluation

Combining Log, Combining Log, Core & Test data.Core & Test data.

Determines the Determines the hydrocarbon in hydrocarbon in place.place.

High resistively indicatingHigh resistively indicatinghydrocarbonhydrocarbon

Low resistively indicatingLow resistively indicatingwaterwater

Deepest oilDeepest oilsandsand

Shallowest waterShallowest watersandsand

PerforationsPerforationsPorosityPorosity

Well CorrelationWell Correlation

Phases of a well




12. Drill to TOTAL DEPTH (TD)13. POOH, and run electric logs14. Run Production liner

Gas

oil

water

MUD TANK

Phases of a well




12. Drill to TOTAL DEPTH (TD)13. POOH, and run electric logs14. Run Production liner15. Cement the liner across

the reservoirGas

oil

water

MUD TANK

Gas

oil

water

MUD TANK

14,000 Kpa

Replace the mud with clean water

1000m x 1kg/litre x 9.81 = 9, 810 Kpa

Gas

oil

water

14.700 Kpa9,810 Kpa

Phases of a well





the reservoir16. Run Production tubing and

perforating gun and Xmas Tree

Gas

oil

water

MUD TANK

Phases of a well






perforating gun17. Hook up flowline to Xmas Tree

Gas

oil

water

MUD TANK

Hook up flowline to production facilities

Gas

oil

water

MUD TANK

ProductionPackerPerforating gun

Xmas tree

On Land LoggingOn Land Logging Using mobile Using mobile

logging units logging units (trucks).(trucks).

Electronic tools are Electronic tools are lowered to measure lowered to measure rock properties & rock properties & perforate the perforate the tubing.tubing.

Shaped charges

Primer Cord

High Explosive

High velocity plasma jet(several million pounds per square inch pressure)

Shaped charges

Primer Cord

Casing

Gun

Phases of a well






perforating gun17. Hook up flowline to Xmas Tree18. Fire the gun

Gas

oil

water

MUD TANK

Hook up flowline to production facilities

Bang!

Phases of a well






perforating gun17. Hook up flowline to Xmas Tree18. Fire the gun19. Gun falls and production starts

Gas

oil

water

MUD TANK

To market

Pressure and Fluid SamplesPressure and Fluid Samples

Source: UK Offshore Oil & Gas

Oil & gas are allowed to flow to the surface under controlled conditions

TESTING A NEW FIELD

Deviated drilling

Multi Lateral wells

Gas

oil

water

Drilling a directional wellDrilling a directional well

Gas

oil

water

MUD TANK

Phases1. Spud in

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bentjoint and motor (only the bit rotates (drill pipe does not rotate).

Bent joint (2 degrees)

Motor

Before we start Before we start directionaldirectional drilling we drilling we have 1 main problem to solvehave 1 main problem to solve

1. We have to know 1. We have to know wherewhere the drill bit is the drill bit is heading.heading.

Compass(shows the direction)

Camera takes picture

Camera takes picture

Modern day tools do not use cameras. Instead they use electronic gyroscopes and down hole computers. Data is sent continuously to the surface by morse codestyle pulses into the mud stream.

plumb bob(shows the inclination from vertical)

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bentjoint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bentjoint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bentjoint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole5. Run casing

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bentjoint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole5. Run casing6. Cement casing in place and install BOP.

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bentjoint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole5. Run casing6. Cement casing in place and install BOP.7. Drill out with holdassembly

Stabilisers(balance the centreof gravity)

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bentjoint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole5. Run casing and BOP6. Cement casing in place and install BOP. 7. Drill out with holdassembly to casing seat8. Pullout

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bentjoint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole5. Run casing and BOP6. Cement casing in place and install BOP. 7. Drill out with holdassembly to casing seat8. Pullout, run casing

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bent joint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole5. Run casing and BOP6. Cement casing in place and install BOP.7. Drill out with holdassembly8. Pullout, run casing to casing seat9. Pump and displace cement

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bent joint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole5. Run casing and BOP6. Cement casing in place and install BOP.7. Drill out with holdassembly8. Pullout, run casing to casing seat9. Pump and displace cement10. Drill out with drop assembly

Gravity pullsthe heavy collarsagainst the Stabiliserpivot point (fulcrum)

Gas

oil

water

MUD TANK

Phases1. Spud in2. Kick off with bent joint and motor (only the bit rotates (drill pipe does not rotate).3. Build up angle to next casing seat.4. Pull out of hole5. Run casing and BOP6. Cement casing in place and install BOP7. Drill out with holdassembly8. Pullout, run casing to casing seat9. Pump and displace cement10. Drillout with dropassembly11. Drill to T.D.

G

Lateral SweepLateral Sweep Vertical well Vertical well

sweeps limited oil sweeps limited oil Lateral re entry Lateral re entry

well access new well access new attic oilattic oil

Blowout Blowout on land on land drillingdrilling

Blowout Blowout in an in an

offshore offshore sitesite

DURING DRILLING All waste shipped back to shore except drilled cuttings Drill cuttings are released onto the ocean floor Drilling fluids based made from water, paraffin oil (baby oil) or vegetable oil Any oil spills must be reported. Oil spills are uncommon and generally small

DURING SEISMIC... Never in migration season Whale watcher on look out Slow pulse starts to warn fish No go into marine parks

ENVIRONMENTENVIRONMENT

Before we start drilling we have 5 main problems to solve

1. We have to loosen the rock

2. We have to remove the rock

3. We have to prevent the hole collapsing

4. We have to prevent water, oil or gas blowing out

5. We have to do all this safely and without harm to the environment (still scope for improvement)

The Geologist s always The Geologist s always

right right .!!!!!.!!!!!

DEEPERDEEPER!!!!!!

QUESTIONS?

drilling for oil and gas

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