Subsea Exercise No.5

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Revised April 2012 Revised April 2012

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Name

Name::____________________________________________________________________________ Date:Date:______________________________________

Complete the Subse

Complete the Subsea vertical kill sheet prov

a vertical kill sheet provided on pages 2 and 3.

ided on pages 2 and 3. Then answer ques

Then answer questions

tions

1 to 12. Please round

1 to 12. Please round calculations as per good well control practice.

calculations as per good well control practice.

Well data : Well data : Hole

Hole size size 8 8 ½ ½ inchesinches

Hole

Hole depth depth (Below (Below RKB) RKB) 6,080 6,080 feet feet MD, MD, 6040 6040 ft ft TVDTVD Casing

Casing shoe shoe depth depth 99 55//88inches, inches, 5000 5000 ft ft MD/TVDMD/TVD

RKB

RKB to to mean mean sea sea level level (MSL) (MSL) 50 50 feetfeet Internal capacities:

Internal capacities: Drill

Drill pipe pipe 5 5 inch inch (S-135-NC50), (S-135-NC50), capacity capacity 0.0178 0.0178 bbl/ftbbl/ft Heavy

Heavy wall wall drill drill pipe pipe 5 5 inch, inch, length length 400 400 ft, ft, capacity capacity 0.0088 0.0088 bbl/ftbbl/ft Drill

Drill collars collars 6 6 ½ ½ inch inch x x 221313//1616inch, length 600 ft, capacity 0.0077bbls/ftinch, length 600 ft, capacity 0.0077bbls/ft

Choke

Choke line line 3 3 inch inch ID, ID, length length 515 515 ft, ft, capacity capacity 0.0087 0.0087 bbls/ftbbls/ft Marine

Marine riser riser length length 500 500 feet, feet, capacity capacity 0.3892 0.3892 bbls/ftbbls/ft Annulus capacities:

Annulus capacities: Drill

Drill collars collars in in open open hole hole 0.0292 0.0292 bbl/ftbbl/ft Drill

Drill pipe pipe and and HWDP HWDP in in open open hole hole 0.0459 0.0459 bbl/ftbbl/ft Drill

Drill pipe pipe and and HWDP HWDP in in casing casing 0.0505 0.0505 bbl/ftbbl/ft Drill

Drill pipe pipe in in Marine Marine riser riser 0.3638 0.3638 bbl/ftbbl/ft Mud pump data:

Mud pump data: Pump

Pump output output at at 98% 98% volumetric volumetric efficiency efficiency 0.102 0.102 bbl/strokebbl/stroke Slow circulation rate data:

Slow circulation rate data: @

@ 45 45 spm spm through through the the riser riser 400 400 psipsi @

@ 45 45 spm spm through through the the choke choke line line 500 500 psipsi Other relevant information:

Other relevant information: Active surface fluid volume

Active surface fluid volume 460 bbl460 bbl Drill

Drill pipe, pipe, 5 5 inch inch closed closed end end displacement displacement 0.0254 0.0254 bbl/ftbbl/ft Seawater

Seawater density density 8.6 8.6 ppgppg

Surface

Surface line line volume volume 14 14 bblsbbls Formation strength test data:

Formation strength test data: Surface

Surface leak-off leak-off pressure pressure with with 10.0 10.0 ppg ppg mud mud 1500 1500 psipsi Kick Data:

Kick Data:

The well kicked at 6040 vertical depth The well kicked at 6040 vertical depth Shut

Shut in in drill drill pipe pipe pressure pressure 600 600 psipsi Shut

Shut in in Casing Casing pressure pressure 870 870 psipsi Recorded

Recorded pit pit gain gain 19 19 bblsbbls Mud

Mud weight weight in in hole hole 10.4 10.4 ppgppg

The well will be killed using the Wait and Weight method The well will be killed using the Wait and Weight method

Answer the following TWELVE questions from the data above. The attached kill sheet may be used Answer the following TWELVE questions from the data above. The attached kill sheet may be used to assist you with your calculations

to assist you with your calculations

Subsea Kill Sheet Exercise No. 5 Subsea Kill Sheet Exercise No. 5

API

API Field) Field) UnitsUnits

SUBSEA KILL SHEET EXERCISE No. 5

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Subsea Kill Sheet Exercise No.5 API Field) Units

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Revised April 2012

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Subsea Kill Sheet Exercise No. 5 API Field) Units

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1. Calculate the pressure safety margin at the casing shoe in this static condition,

assuming the top of the kick is below the casing shoe.

Answer____________ psi

4 p o i n t s

2. How many strokes are required to pump from pump to bit?

Answer____________ strokes

4 p o i n t s

3. How many strokes are required to pump from the bit to casing shoe?

Answer____________ strokes

4 p o i n t s

4. How much time is required to circulate the total well system volume?

Answer____________ minutes

4 p o i n t s

5. How many strokes are required to displace the marine riser to kill fluid before opening

the BOP?

Answer____________ strokes

4 p o i n t s

6. What is the kill mud density?

Answer____________ ppg

4 p o i n t s

7. What is the Initial Circulating Pressure?

Answer____________ psi

4 p o i n t s

8. What is the Final Circulating Pressure?

Answer____________ psi

4 p o i n t s

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Revised April 2012

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9. What is the Initial dynamic casing pressure at kill pump rate?

Answer____________ psi

4 p o i n t s

10. What is the MAASP after circulation of the kill mud?

Answer____________ psi

4 p o i n t s

11. Calculate the pressure drop per 100 strokes of kill mud fluid pumped inside the drill

string.

Answer____________ psi/100 strokes

4 p o i n t s

12. If all the influx is at the bottom of the hole, calculate the gradient of the influx.

Answer____________ psi/ft

4 p o i n t s

Subsea Kill Sheet Exercise No. 5 API Field) Units

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Before attempting to fill in the kill sheet, draw a simple sketch of the well to determine the total

annulus lengths. An example is shown below. Only use measured depths and remember that

total annulus length (including the choke line) may not equal measured depth if the Choke line

length is greater than the Riser length.

SUBSEA KILL SHEET EXERCISE NO. 5

Answers

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Revised April 2012

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Subsea Kill Sheet Exercise No. 5 - Answers API Field) Units

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Revised April 2012

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Pressure Safety Margin = MAASP

–

SICP

= 1378 psi

–

870 psi

= 508 psi

From Kill Sheet, surface to bit strokes = 967 stokes

Surface line strokes = 14 bbls

÷

0.102 bbl/stroke = 137 strokes

Pump to Bit stokes = 967 + 137 = 1104 strokes

New MAASP = (Max. Allowable Mud Density

–

Kill Mud Density) x 0.052 x TVDshoe

= (15.7 ppg

–

12.4 ppg) x 0.052 x 5000 ft.

= 858 psi

54 psi/100 strokes

SUBSEA KILL SHEET EXERCISE NO. 5

Answers

1. 508 psi

2. 1104 strokes

3. 388 strokes

4. 80 - 81 minutes 80.6 minutes)

5. 1782 - 1786 strokes 1784 strokes)

6. 12.4 ppg

7. 1000 psi

8. 477 psi

9. 770 psi

10. 858 psi

11.

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