# Well Control Quiz 4

Tutorial prepared by Eltun Talibov, Drilling Engineer at State Oil Company of AZERBAIJAN REPUBLIC (SOCAR), Email:Eltun-talibov98@mail.ru

Problem 1 (open question)

At the depth of 9600 ft driller observes total losses and immediately pumps seawater into the annulus until there are returns at the flow line. Using following data calculate how many feet of seawater are in the annulus when returns are observed?
Depth 9600 ft
MW= 12.5 ppg
Seawater weight = 8.6 ppg
Formation gradient = 0.515 psi/ft

Problem 2

Using the BOP configuration shown in the image. With no drill pipe in the hole, is it possible to shut the well in under pressure and change the pipe rams?

A) Yes
B) No

Problem 3

During POOH swabbing was suspected. The flow check was negative and it was decided to run back to bottom (20 stands) checking for flow after lowering every 5 stands. The flow checks after 5, 10 stands showed no flow. But with stand number 15 back in the hole, the well was found to be flowing.

What could be the most likely cause of the well flow?

A) Abnormal formation fluid pressure.
B) Derrick man mixed too light slug prior to pulling out of the hole.
C) Running into the swabbed fluids caused hydrostatic pressure in annulus to drop.
D) In the hurry, it was forgotten to slug the pipe while preparing for running back

Problem 4

Which of the following causes of well kick is totally avoidable and is due to lack of alertness of driller? (Select two answers)

A) Drill pipe is lowered too fast in heavy mud causing lost circulation
B) Gas cut mud
C) Abnormal pressure
D) Not keeping hole full

Problem 5

Cuttings volume in the annulus is high and the well is shut in on a kick. Would the drill pipe pressure be higher or lower than it was in a clean well

A) Lower
B) Higher
C) The same

Problem 6

While drilling a vertical oil well, at 15000 ft depth with a mud weight of 16 ppg, gas kick detected. Initial kick volume is 10 bbl. Using the picture below, answer the questions:

What will be the gas volume at 8450ft, 3280ft and at the surface ( open well) ? (round up figure)

A) 16.54; 65.8; 9202 bbl
B) 17.75; 45.73; 8490 bbl
C) 20; 42.44; 7541 bbl
D) 30.02; 67.82; 6284 bbl

Problem 7

When starting a kill operation, the choke pressure is held constant whilst bringing pump up to speed. The drill pipe pressure gauge reads 150 psi higher than the calculated Initial Circulating Pressure (ICP). What action should be taken?

A) There will now be 150 psi overbalance on the bottom. Nothing needs to be done
B) Open the choke and let the standpipe pressure drop to the calculated value (ICP)
C) Continue to circulate with the new ICP and adjust the drill pipe pressure graph

Problem 8

Which of the following parameters are affected by formation permeability? (Select 3 answers)

A) Influx volume
B) ICP
C) Kill mud weight
D) Time for pressures to stabilize
E) SICP
F) SIDPP

Problem 9

Why is casing pressure usually higher than the shut-in drill pipe pressure?

A) Choke line is larger in diameter than Kill line
B) The influx fluid is usually lighter than the mud weight in the hole
C) The choke line is longer than the Kill line
D) Cuttings in the annulus help reduce the hydrostatic pressure

Problem 10

With the pumps running continuously a heavy pill mud is circulated. When will bottom hole pressure start to increase?

A) Once all the pill is in the annulus
B) Once the pill starts to be displaced into the annulus
C) As soon as the pill starts to be pumped down the drill string
D) Once all the pill is pumped inside drill string and is about to exit the bit