Page 311 - Well Control for Completions and Interventions

Well Kill, Kick Detection, and Well Shut-In 303

pressure downhole. For the sake of simplicity and consistency the
first lubrication will use the calculated maximum tubing volume
(10 bbls):

4911x160
Surface pressure after pumping 10 bbl 5 5 5238 psi:
ð 150Þ
The casing (7 bbls capacity) has been filled with kill fluid. The
remaining 3 bbls pumped is filling the tubing, placing the fluid level
at 3/0.0149 5 201 ft. above the tubing end (10,260 201 5 10,059).
The head of fluid pumped is (10,450 2 10,059) 3 (0.572 2 0.08) 5
192 psi.
BHP after pumping 10 bbls is:

5238 1 ð10; 059 3 0:08Þ 1 ð10; 450 2 10; 059Þ 3 0:572 5 6266 psi:

6. Bleed off to the starting pressure of 4911. Bleed an additional 192 psi
(the head of fluid pumped) 5 4719 psi. The BHP is after bleeding off is:

4719 1 ð10; 059 3 0:08Þ 1 ð10; 450 10:059Þ 3 0:572Þ 5 5747 psi.
7. Pump a second 10 bbl batch of fluid. The pressure increase due to gas
compression is:
4719 3 150
Surface pressure 5 5 5056 psi
140
10 bbls of fluid fills 10/0.0149 5 671 ft. of tubing. The fluid level
is at 10,059-671 5 9388 ft. The BHP is 5056 1 (9388 3 0.08) 1
(10,450 2 9388) 3 0.572 5 6414 psi.
8. Bleed back pressure to the starting WHCIP of 4719 bleed an
additional 330 psi (the head of fluid pumped) 5 4389 psi. The new
pressure downhole is
4389 1 ð9388 3 0:08Þ 1 ð10; 450 2 9388Þ 3 0:572 5 5747 psi:

9. Continue pumping 10 bbl batches of fluid. The pressure reduction
should be approximately 330 psi with each cycle of lubricate and
bleed. As with the first (plugged) example, it is useful to build a
spreadsheet (Table 7.15). This keeps track of surface and downhole
pressure as the kill progresses.