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Accumulator Capacity – Usable Volume per Bottle Calculation (Surface Stack)

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Accumulator (Koomey) is a unit used to hydraulically operate Rams BOP, Annular BOP, HCR and some hydraulic equipment. There are several of high pressure cylinders that store gas (in bladders) and hydraulic fluid or water under pressure for hydraulic activated systems. The primary purpose of this unit is to supply hydraulic power to the BOP stack in order to close/open BOP stack for both normal operational and emergency situation. Stored hydraulic in the system can provide hydraulic power to close BOP’s in well control operation, therefore, kick volume will be minimize. Accumulators should have sufficient volume to close/open all preventers and accumulator pressure must be maintained all time.

koomey-unit

This post you will learn how to calculate usable volume per bottle by applying Boyle’s gas law:

Use following information as guideline for calculation:

Volume per bottle = 10 gal

Pre-charge pressure = 1000 psi

Operating pressure = 3000 psi

Minimum system pressure = 1200 psi

Pressure gradient of hydraulic fluid = 0.445 psi/ft

For surface application

Step 1 Determine hydraulic fluid required to increase pressure from pre-charge pressure to minimum:

Boyle’s Law for ideal gase: P1 V1 = P2 V2

P1 V1 = P2 V2

1000 psi x 10 gal = 1200 psi x V2

10,000 ÷ 1200 = V2

V2 = 8.3 gal

It means that N2 will be compressed from 10 gal to 8.3 gal in order to reach minimum operating pressure. Therefore, 1.7 gal (10.0 – 8.3 = 1.7 gal) of hydraulic fluid is used for compressing to minimum system pressure.

Step 2 Determine hydraulic required increasing pressure from pre-charge to operating pressure:

P1 V1 = P2 V2

1000 psi x 10 gals = 3000 psi x V2

10,000 ÷3000 = V2

V2= 3.3 gal

It means that N2 will be compressed from 10 gal to 3.3 gal. Therefore, 6.7 gal (10.0 – 3.3 = 6.7 gal) of hydraulic fluid is used for compressing to operating pressure.

Step 3 Determine usable fluid volume per bottle:

Usable volume per bottle = Hydraulic used to compress fluid to operating pressure – hydraulic volume used to compress fluid to minimum pressure

Usable volume per bottle = 6.7 – 1.7

Usable volume per bottle = 5.0 gallons

Reference book: Well Control Books
Formulas and Calculations for Drilling, Production and Workover, Second Edition

Oil Field Coversion Part 3 Oil Field Conversion Part 3 – Pressure,Velocity,Volume,Weight

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The last part of unit conversion is the conversion for  Pressure,Velocity, Volume and Weight specially used in the oilfield.

The RED number is the conversion unit.

Pressure

Atmospheres x 14.696 = Pounds/sq inch

Atmospheres x 1.033 = Kilograms/sq cm

Atmospheres x 101300 = Pascals

Kilograms/sq cm x 0.9678 = Atmospheres

Kilograms/sq cm x 14.223 = Pounds/sq inch

Kilograms/sq cm x 0.9678 = Atmospheres

Pounds/sq inch x 0.068 = Atmospheres

Pounds/sq inch x 0.0703 = Kilograms/sq cm

Pounds/sq inch x 0.006894 = Pascals

Velocity

Feet/sec x 0.305 = Meters/sec

Feet/mm x 0.00508 = Meters/sec

Meters/sec x 196.8 = Feet/mm

Meters/sec x 3.28 = Feet/sec

Volume

Barrels x 42 = Gallons

Cubic centimeters x 0.00003531 = Cubic feet

Cubic centimeters x 0.06102 = Cubic inches

Cubic centimeters x 0.000001 = Cubic meters

Cubic centimeters x 0.000264 = Gallons

Cubic centimeters x 0.001 = Litters

Cubic feet x 28320 = Cubic centimeters

Cubic feet x 1728 = Cubic inches

Cubic feet x 0.02832 = Cubic meters

Cubic feet x 7.48 = Gallons

Cubic feet x 28.32 = Litters

Cubic inches x 16.39 = Cubic centimeters

Cubic inches x 0.0005787 = Cubic feet

Cubic inches x 0.00001639 = Cubic meters

Cubic inches x 0.004329 = Gallons

Cubic inches x 0.01639 = Liters

Cubic meters x 1000000 = Cubic centimeters

Cubic meters x 35.31 = Cubic feet

Cubic meters x 264.2 = Gallons

Gallons x 0.0238 = Barrels

Gallons x 3785 = Cubic centimeters

Gallons x 0.1337 = Cubic feet

Gallons x 231 = Cubic inches

Gallons x 0.003785 = Cubic meters

Gallons x 3.785 = Liters

Weight

Pounds x 0.0004535 = Tons (metric)

Tons (metric) x 2205 = Pounds

Tons (metric) x 1000 = Kilograms

Ref book: Formulas and Calculations for Drilling, Production and Workover, Second Edition

Oil Field Conversion Part 2 – Length,Mud Weight,Power

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The second part of unit conversion is the conversion for  Length,Mud Weight and Power specially used in the oil field.

The RED number is the conversion unit.

Length

Feet x 0.305 = Meters

Inches x 25.4 = Millimeters

Inches x 2.54 = Centimeters

Centimeters x 0.394 = Inches

Millimeters x 0.03937 = Inches

Meters x 3.281 = Feet

Mud Weight

Pounds/gallon x 7.48 = Pounds/cu ft

Pounds/gallon x 0.12 = Specific gravity

Pounds/gallon x 0.1198 = Grams/cu cm

Grams/cu cm x 8.347 = Pounds/gallon

Pounds/cu ft x 0.134 = Pounds/gallon

Specific gravity x 8.34 = Pounds/gallon

Power

Horsepower x 1.014 = Horsepower (metric)

Horsepower x 0.746 = Kilowatts

Horsepower x 550 = Foot-pounds/sec

Horsepower (metric) x 0.986 = Horsepower

Horsepower (metric) x 542.5 = Foot-pounds/sec

Kilowatts x 1.341 = Horsepower

Foot pounds/sec x 0.00181 = Horsepower

Ref book: Formulas and Calculations for Drilling, Production and Workover, Second Edition

Oil Field Conversion Part 1 – Area, Circulation Rate, Impact Force

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Working in the oil filed, you may need to convert some unit values to another unit valves.  I have some conversion unit specially used in the drilling and working over industry.  I have 3 parts of the oil field conversion unit. This is the first part which is the conversion of Area, Circulation Rate, Impact Force.

The RED number is the conversion unit.

Area

Square inches x 6.45 = Square centimeters

Square inches x 645 = Square millimeters

Square centimeters x 0.155 = Square inches

Square millimeters x 0.00155 = Square inches

Circulation Rate

Barrels/min x 42 = Gallons/min

Cubic feet/min x 0.000472 = Cubic meters/sec

Cubic feet/min x 7.48 = Gallons/min

Cubic feel/mm x 28.32 = Liters/min

Cubic meters/sec x 15850 = Gallons/min

Cubic meters/sec x 2118 = Cubic feet/min

Cubic meters/sec x 60000 = Litres/min

Gallons/min x 0.0238 = Barrels/ruin

Gallons/min x 0.134 = Cubic feet/min

Gallons/min x 3.79 = Litres/min

Gallons/min x 0.00006309 = Cubic meters/sec

Litres/min x 0.00001667 = Cubic meters/sec

Litres/min x 0.0353 = Cubic feet/min

Litres/min x 0.264 = Gallons/min

Impact Force

Pounds x 0.0000445 = Dynes

Pounds x 0.454 = Kilograms

Pounds x 4.448 = Newtons

Dynes x0.00000225 = Pounds

Kilograms x 2.2 = Pounds

Newtons x 0.2248 = Pounds

I hope this conversion unit will be advantageous for you.

Ref book: Formulas and Calculations for Drilling, Production and Workover, Second Edition

West Atlas re-boarded – Photos Included

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west-atlast-jack-up

Latest information about West Atlas and please find the media release from PTTEP t from the link below. You will see the photos of West Atlas after well control situation burnt the rig and the platform in Timor sea.

http://www.coogeeresources.com.au/uploads/MediaRelease96_23-11-09.pdf

From “Upstream Online” 23/11/09.

Crew Boards Crippled Montara Platform

A three-man team has boarded the Montara wellhead platform for the first time since a blowout at the Timor Sea installation on 21 August.

The crew, from Alert Well Control, are evaluating the damage to the Seadrill-owned jack-up West Atlas and the platform, PTTEP said.

The evaluation will also include a safety assessment as PTTEP considers how best to plug and fully secure the Montara H1 well.

PTTEP said the wellhead platform and blown-out H1 well remain stable after the leaking bore was successfully killed on 3 November.

Company director Jose Martins said a preliminary assessment of the rig shows extensive damage to equipment from a fire which erupted on the wellhead platform on 1 November.

He said the reboarding team were surveying the structural integrity of the West Atlas’ cantilever which buckled in the platform fire.

“PTTEP will ensure everything possible has been done to assess the risks before undertaking the plugging operation. The safety of personnel remains our first priority,” Martins added.