Page 294 - Well Control for Completions and Interventions

Well Kill, Kick Detection, and Well Shut-In 287

Final mechanical limit (tubing full of kill fluid):
6744 2 10:530:05236070 5 3430
Tbgworkingburstpress Tubinghydrostaticpressure ðatpackerÞ Final limit ðtubing fullof killfluidÞ

5. Calculate bullhead volume. Surface to top of formation (bbls).
Tubing:

0:01521 3 6201 5 94:25
Tubing capacity factor ðbbls=ft:Þ Tubing length ðMDÞ Barrels required
Casing (or liner) to top of formation:
0:01521 3 10; 499 2 6201 5 65:32 bbls
Liner capacity factor To top of formation Barrels required
Total volume:
94:25 1 65:32 5 159:57 bbls
Tubing volume Liner to formation Total volume
Total strokes (if applicable):
159:57 = 0:0315 5 5066
Tubing volume bbls bbls=stk Strokes for total volume

With the kill sheet complete, a plot can be prepared showing volume
pumped versus fracture and mechanical pressure limits. The plot should
also show the lower pressure limit, i.e., the minimum surface pump pres-
sure required to maintain a 200 psi overbalance. At the well site, the
pump operator would be supplied with a copy of the plot. The pump is
inherently conservative with regards to maximum pressure. Downhole
pressure will be lower than calculated by a value equal to frictional pres-
sure drop between surface and the reservoir (Fig. 7.15).

7.5 GAS LAWS AND GAS BEHAVIOR

Gas volume changes with pressure and temperature. As gas moves
towards the surface, the reduction of HP in the fluid column allows the gas to
expand. Boyle’s law is used to calculate how much expansion will take place.
In 1660, Robert Boyle established the relationship between gas volume and
pressure for an ideal gas. The relationship between pressure and volume is:
P 1 V 1 5 P 2 V 2
where:
P 1 : initial gas pressure;
V 1 : initial gas volume;