STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

Drilling Muds and Completion Fluids 687
Typical Calculations In Mud Engineering
Weighing Mud Up-Unlimited
Volume
It is desired to increase the specific weight of 300 bbl of 10.5-lb/gal mud to
11.4-lb/gal using barite. The final volume is not limited. Determine the new
volume of the mud. Also determine the weight of the barite to be added [7].
The new volume, V, (bbl), is
(4-45)
where V, = the initial volume in bbl
7, = the specific weight of the initial mud in lb/gal
7, = the specific weight of the final mud in lb/gal
7, = the specific weight of barite (35.0 lb/gal).
Therefore, the final volume is
(35.0 - 10.5)
V, = (300)
(35.0-11.4)
= 311.44 bbl
The weight of the barite to be added is
Wb = (311.44 - 300.00)(35.0)(42)
= 16.817 lb
Weighing Mud Up-Limited
Volume
Example. It is desired to increase the specific weight of 700 bbl of 12.0-lb/gal
mud to 14.0-lb/gal mud. To keep the new mixture from becoming too viscous,
1 gal of water is to be added with each 100-lb sack of barite. A final mud volume
of 700 bbl is required. Determine the volume of initial mud that should be
discarded and the weight of barite to be added 171.
The initial and final volumes are related by
(4-46)
and the weight of barite added is
(4-47)