8/17/2019 TEST 2 PCB-4213 Advanced Drilling Engineering
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Test-2 / PCB-4213 Advanced Drilling Engineering Jan-2016
Internal
Question 1
(A) Briefly describe the FOUR (4 ) reasons for implementing plug
cementing job.
[6 marks] (B) Briefly explain the effect of sulphate mineral on
well cementing. [2 marks]
(C) List down the THREE (3) additives used for filtrateion loss
control. [3 marks]
(D) Explain, why drilling is faster in underbalanced drilling
operations?. [2 marks]
Question 2
A 12.3 ppg drilling mud is being pumped at 700 gpm through the
tri-cone Bit which has
three 12/32 inch diameter nozzle sizes. Analyze the pressure
loss across the bit.[5 marks]
Question 3
The 12-1/4 in. bit is necessary to change due to the significant
reduction in rate of
penetration. The bit currently in use has three 12/32-in
nozzles. The driller has
recorded that when the 9.6 lbm/gal mud is pumped at a rate of
485 gal/min, a pump
pressure of 2800 psig is observed and when the pump is slowed to
a rate of 247
gal/min, a pump pressure of 900 psig is observed. The pump is
rated at 1,250 hp and
has an efficiency of 0.91. The minimum flow rate to lift the
cuttings is 225 gal/min. The
maximum allowable surface pressure is 3000psig. The last 13-3/8
in. surface casing
is set at 3000ft. and the mud density will remain unchanged in
the next bit run.
a. Select the optimum pump rate for better hole cleaning. [6
marks]
b. Select the optimum nozzle sizes for next bit run using IF
criteria.
[4 marks]
Question 4
A wellbore to be cemented has got enlarged between 300 ft. to
400 ft. due to the soft
formation encountered and tight between 1200 ft. to 1300 ft. The
enlarged and tight
sections of the welbore having diameters 19-1/2 in. and 15-1/2
in. respectively.
Determine the following .
a. Height, ft. of the TAIL cement in the annulus [3 marks]
b. Depth, ft. of the top of the cement. [3 marks]
c. Number of strokes required to displace the cement. [3
marks]
d. Number of sakes required for the TAIL cement (Yield 1.25). [3
marks]
TEST-2PCB-4213 ADVANCED DRILLING ENGINEERING
JANUARY 2016 SEMESTER
