Volumes and Strokes

Drill string volume, barrels

Annular volume, barrels

Strokes to displace: drill string, annulus, and total circulation from kelly to shale shaker

• Example: Determine volumes and strokes for the following:

  Drill pipe 5.0 in. 19.5 lb/ft
  	Inside diameter	= 4.276 in.
  Length	= 9400 ft
  Drill collars 8.0 in. OD
  	Inside diameter	= 3.0 in.
  Length	= 600 ft
  Casing 13-3/8 in. 54.5 lb/ft
  	Inside diameter	= 12.615 in.
  Setting depth	= 4500 ft
  Pump data 7 in. by 12 in. triplex
  	Efficiency	= 95%
  Pump output	= 0.136 @ 95%
  Hole size	= 12-1/4 in.

Drill string volume

1. Drill pipe volume, bbl:

   • 

   • Barrels = 0.01776 9400 ft

   • Barrels = 166.94

1. Drill collar volume, bbl:

   • 

   • Barrels = 0.0087 600 ft

   • Barrels = 5.24

1. Total drill string volume:

   • Total drill string vol, bbl = 166.94 bbl + 5.24 bbl

   • Total drill string vol = 172.18 bbl

Annular volume

1. Drill collar/open hole:

   • 

   • Barrels = 0.0836 600 ft

   • Barrels = 50.16

1. Drill pipe/open hole:

   • 

   • Barrels = 0.12149 4900 ft

   • Barrels = 595.3

1. Drill pipe/cased hole:

   • 

   • Barrels = 0.130307 4500 ft

   • Barrels = 586.38

1. Total annular volume:

   • Total annular vol = 50.16 + 595.3 + 586.38

   • Total annular vol = 1231.84 barrels

Strokes

1. Surface-to-bit strokes:

   • 
     

     Surface-to-bit strokes = 172.16 bbl 0.136 bbl/stk

   • Surface-to-bit strokes = 1266

1. Bit-to-surface (or bottoms-up) strokes:

   • 
     

     Bit-to-surface strokes...