Pipe displacement, normally in bbl/ft or m3/m, is steel volume per length of steel pipe. When we either pull out of hole or trip in hole for any kind of pipes such as drill pipe, casing or tubing, you should know how much fluid to displace steel volume.
For example, when we pull out of hole, a trip sheet must be monitored all time. We must know how much fluid will fill the hole each stand of drill pipe pulled out. If the volume of displacement less than theoretical displacement value, we may have problem due to swabbing formation into wellbore.
This article will demonstrate how to calculate plain pipe displacement with this following formula:
Pipe Displacement in bbl/ft = (OD2 – ID2 ) ÷ 1029.4
OD in inch
ID in inch
OD is out side diameter of pipe in inch.
ID is inside diameter of pipe in inch.
This formula is for plain pipe diplacment such as casing and tubing. It is not for closed-end displacement. It’s not accurate enough for drill pipe because this formula does not account for tool joint displacement therefore you need drill pipe specification sheet for its displacement.
Example: Determine pipe displacement in bbl/ft of 9-5/8” casing 40 ppf, OD = 9.625 in, ID = 8.835 in
Pipe Displacement of 9-5/8” casing 40 ppf in bbl/ft = (9.6252 – 8.8352 ) ÷1029.4
Pipe Displacement of 9-5/8” casing 40 ppf in bbl/ft = 0.01417 bbl/ft
Annular capacity in m3/m = (OD2 – ID2) ÷1,273,240
OD in mm
ID in mm
Example: Determine pipe displacement in bbl/ft of 9-5/8” casing 40 ppf, OD = 244.475 mm, ID = 244.409 mm
Pipe Displacement of 9-5/8” casing 40 ppf in m3/m = (244.4752 – 244.4092 ) ÷1,273,240
Pipe Displacement of 9-5/8” casing 40 ppf in m3//m = 0.0074
Lapeyrouse, N.J., 2002. Formulas and calculations for drilling, production and workover, Boston: Gulf Professional publishing.
Bourgoyne, A.J.T., Chenevert , M.E. & Millheim, K.K., 1986. SPE Textbook Series, Volume 2: Applied Drilling Engineering, Society of Petroleum Engineers.
Mitchell, R.F., Miska, S. & Aadny, B.S., 2011. Fundamentals of drilling engineering, Richardson, TX: Society of Petroleum Engineers.