11. Formation Testing

8/9/2019 11. Formation Testing

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TAMU - PemexOffshore Drilling

Lesson 11

Formation Testing


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Formation Testing

Downhole Test Equipment - valve

Slip Joints

Test String

Surface Test Equipment

T = H + wd


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Formation Testing

Exploration wells are drilled primarily for

information (not production):

from logs

drilled cuttings

cores

DSTs, etc.

Testing from floater is very expensive.Careful planning is therefore essential.

Appropriate selection of equipment for testing is essential. Order equipment early.


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Safety Precautions - Well Testing

1. Always set the test packer in the

casing or in the liner, never in the

open hole.

2. Perform testing in a liner or casing.

3. Use a test tree in the BOP stack.

Include an emergency downhole shut-off near the formation. Safety devices

will be discussed with the equipment.


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Safety Precautions

4. Stop the test if any of the following

danger signals occur:

a. Pressure approaches the pressure

rating of any of the equipment used.

b. Equipment becomes overloaded by

excessive production.

c.Annular pressure indicatescommunication between the annulus

and the test string.


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Safety Precautions

4. Danger signals, (continued)

d. Gases reach explosive levels incritical areas, or poison gases

are produced.

e. Vessel motion approaches

unsafe conditions.


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Safety Precautions

5. Commence flow during daylight

6. Release packer during daylight


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Test Valve

operated

by AnnulusPressure

Apply

Annulus

Pressure

2,000-2,500

psiApply 1,000-1,500 psi to start flow

Halliburton and Johnston both have test valves of this type. Below 1,000 psi valve is closed.


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Johnston MFE

(Multiple Flow Evaluator)

Valve is opened by reciprocation and

requires a full cycle before actuation.

When tool is first set down on packer, the test

valve will open after 3-5 minutes.

Picking up and setting down will shut off the

flow.


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Johnston MFE (contd)

Each alternate reciprocation cycle will open

or close the valve.

Valve can be opened or closed any numberof times.

Halliburton Hydraspring Tester isopened by compression; is closed when no

compression. Set for ~ 20,000 lbf.


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Slip Joint Safety Valve.

Top of Upper Most Slip Joint

Valve Mandrel ofSlip

Joint Safety Valve

Bottom of LowerSlip Joint

Seal and Port Section of

Safety Valve

Opens when in tension. Closed when in compression.

Shuts off flow. RUN below mud line.


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Figure8.3

Volume -

pressure

balancedslip joint.

Port to Tubing

Chamber for

Tubing Fluid

Chamber forAnnular Fluid

Port to Wellbore

Designed to eliminate pressure and flow surges resulting

from vessel heave. V = const (?)

{not needed with heave compensation system}


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Figure 8.4

Example ofseafloor

shut-in

equipment.

Shear-Blind

Rams Closed

Valves Closed

K&C Valves Open

- to monitor annulus

pressure

Pipe Rams Closed

Valves Open

Hang-off Joint

During Test

Annulus

Pressure

Control

Produced Fluids

to Surface

(a) During Test

Tree inside the BOP and Wellhead. Hydraulic pressure from surface holds valves open.

(b) Well Shut in.

Connections to

Surface Removed


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Space Out for Test Tools

The space out procedure can be as follows:

1. Land shoulder in wellhead and mark

pipe (only the large shoulder will land

in the wellhead).

2. Pick up at about 18 feet (shoulder about

4 feet above rams)3. Close rams & land shoulder by lowering

4 feet


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Space Out-continued

4. Mark Pipe

5. Open rams and pick up 20 feet

a. Lower slip joint stroke 12 feet

b. Tester open 2 feet

c. Packer set distance 1 foot

Half of upper slip joint 5 feet

6. Set Packer


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Space Out-continued

7. Lower handoff shoulder and hang off

on rams. When the packer is set, the

hang off point on the tool will be about

19 feet above the rams.

NOTE:A weight loss approximately equal

to the weight of the string below theupper slip joints will indicate that the

packer has been set.


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Subsea test tree

Test valve

Pressure recorder

Slip joints

Slip joints safety valves

Packer

Hydraulic line

Figure 8.5

Example test

string

arrangement


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Figure 8.6

Test string- flowing

position

Hydraulic Hose

for Test Tree

Mudline

Upper Test TreeShoulder Landed on

Pipe Rams

7 Casing

3 1/2 Tubing

20,000 lbs of

3 1/2 tubing

Packer

Perfs.

UpperSlip Joints

Reciprocal Tester (Open)

LowerSlip Joints


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Test Valve Procedure:

The test tree in the example (Table 8-1)

has the distance of eight feet between

the upper hang-off shoulder and the

lower hang-off shoulder. In this case,the procedure might be:

1. Land the tree in wellhead andmark pipe (only large shoulder will

land in the wellhead).


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Test Valve Procedure:

3. Close rams and land upper shoulder

by lowering string about 4 ft.

4. Mark pipe.

5. Open rams and pick up about 17 ft.

6. Set packer and lower string to about

10 ft. below the lower mark.

7. Close rams and land lower shoulderon the rams by lowering the string about

2 ft.


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Legend

SSV Surface Safety Value

SA Sample Connection

CI Chemical Injection

DWT Dead Weight TesterTI Temperature Indicator

HP High Pressure

LP Low Pressure

Figure 8.8

Schematic ofan oil well test

system.

1. Gas Oil Flushing

2. Water Flushing

3. Pressure Testing

4. Kill Line

Separator Separator

Heater

Flowline Manifold

Manifold

Tank Piston

Pump

Burner


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Horizontal Test Separator

OIL

WATER

GAS

Measure flow rates for of gas and oil. Record pressures and choke size. Do not overload.


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Gas Inlet

Atomizing

Gas/Air Inlet

Forward

WaterSpray

Heat Shield

WaterSpray

Oil Inlet

Isometric section of a 10,000 BOPD burner

Smokeless Incineration - i.e., complete combustion

Atomize the oil spray, add air or air/gas mixture. Ignited by pilot. Electric ignition. Heat shield


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(W = w (s

Consider a small section

of the anchor chain:

(T = ?

E

(T = (W sin E

Prove: T = H + wd

Along chain:

7F = 0

E


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(T = (W sin E

But,(

W = w(

sso, (T = w (s sin E

But, (s sin E = (h

so,(

T = w(

h

7 (T = 7 w (h = w 7 (h

(T = ?

E

Prove: T = H + wd

(h


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Prove: T = H + wd

(T = w (h

7 (T = 7 w (h = w 7 (h

T - H = wh

T = H + wd

QED

(T = ?

H

h


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Alternate Proof: T = H + wd

H


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)iv(0dx

dy0,xwhen

(iii)w

Hdy

(ii)tandxdy

(i)cosTH

!!

!

U!

U!

Alternate Proof: T = H + wd

H


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Prove: T = H + wd

:Catenaryof

H

xwcosh

w

Hy

!

(vi)

H

xwhsin

H

w

w

H

dx

dy

!@

(vii)H

xwsinhtan:(ii)Eqn.From

!U@

(v)


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Prove: H = H + wd

U!U!U

!2

c sT:(i). secHsecHFr

!U!

H

xwsinh1Htan1H:(vii)Eqn.From 22

!

!

HxwcoshcoshH 2 H

HxwT


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Prove: H =T- wd

wycosFrom !

!

H

xwh

w

wHT:(v)Eqn.

HwdFrom !

!

w

HdwT:(iii)Eqn.

wdHT !.e.i

( )

!

H

xwcosh


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NAVS

TAR GPS

NAVSTAR:

Navigation System withTime and Ranging

GPS: Global Positioning System


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Frequently Asked Questions

1. What is GPS?

2. How is GPS used?

3. Who uses GPS?

4. Whats the status of the GPS?

5. What is the Standard Positioning Service?

6. Where can I find courses on GPS?7. What is the status of Selective Availability (SA)?

8. What is GPS Rollover?


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NAVSTAR GPS

A space-based radio positioning system

designed to provide highly accurate,

continuous, world-wide positioning, velocity,and time information . . .

to an unlimited number of suitably equippedusers anywhere on or near the surface of the

earth.


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NAVSTAR GPS

System Components

Space (Transmitter)

Control

User (Receiver)


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Space Segments

Consists of a constellation

of24 satellites in six orbital planes

(inclined at 55 degrees)

orbiting at an altitude of10,900 miles.

Nominal period of orbit is 12 hrs.


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Control Segment

based at Falcon AFB, CO

1 - Master Control Station

2 - Monitor stations & ground antennasfor communications and control

Users

Vehicle tracking to surveyingHandheld to large vehicles


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Transmits continuously on the same

two L-band Frequencies

C/A-Code-Coarse Acquisition

(Civilian)

P-Code-Precision Code (Encrypted

Military)

NAVSTAR GPS


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Unknowns (4)

Knowns (4)

Satellites

n,U,U,U

NAVSTAR GPS


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Loran C/D

Ground based radio navigation

Coverage --- regional

Range --- 1,800 miles

Error 2-D --- 1,500 ft


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Omega

Eight very low frequency transmitters

ground based radio navigation

Coverage --- 98% of globe (night)

88% of globe (day)

Error 2-D --- 2-4 nautical miles

1,000 to 2,000 ft DN mode


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Transit

Five to eight satellite constellation low

altitude polar orbit

Space borne radio navigation system

Coverage --- global but intermittent 2-D

Error --- 1500 ft


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NAVSTAR GPS

C/A-Code-Coarse Acquisition (Civilian)

Coverage --- Global instantaneous

Error 2-D --- 330 ft

P-Code-Precision Code (EncryptedMilitary)

Error 2-D --- a few ft

11. Formation Testing

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