Pune University BE Petroleum Engineering Well Control Methods Question Papers

B.E. (Petroleum) WELL CONTROL METHODS (2008 Pattern) (Elective – IV) (Sem. – II)

Time :3 Hours]                                                                           [Max. Marks :100

Instructions to the candidates:

1)            Answer 3 questions from Section -1 and 3 questions from Section – II.

2)            Answers to the two sections should be written in separate books.

3)            Neat diagrams must be drawn wherever necessary.

4)            Pigures to the right indicate full marks.

5)            Use of logarithmic tables, slide rule, Mollier charts, electronic pocket calculator and steam tables is allowed.

6)            Assume suitable data, if necessary.

SECTION – I

QIA a) Discuss BHP (Bottom hole pressure) in following different well situations.

[6]

i)              When not circulating

ii)           While drilling

iii)         Shutting the well after a kick

iv)         While tripping in

v)            While tripping out

b) What is leak off test? Discuss necessity and test procedure in brief. Calculate LOT value in ppg if casing shoe depth is 8000 ft TVD/8250 ft (MD), Mud weight – 10 ppg, LOT pressure – 1200 psi, find out formation leak-off pressure.                       [12]

OR

Q2) a) What is MAASP? a casing is lowered to a depth of 9500 ft, shoe TVD 8700 ft. After drilling shoe 8 15 ft of formation, leak of test was conducted with 11.6 ppg mud. Calculate                                                                                                              [8]

i)             MAASP if sub-surface formation leak-off pressure is 6500 psi.

ii)           MAASP if formation fracture gradient is 0.75 psi/ft.

b)        Discuss shallow gas hazard in top hole drilling in detail.                   [8]

c)        Discuss causes of reduction in hydrostatic head.                                  [2]

 

Q3) a) Discuss shut in procedures (As per API RP59) for land/jack-up rigs, in brief while drilling.                                                                                                                               [8]

b) Calculate influx height, gradient and nature of influx.                                   [8]

SIDPP = 500 psi SICP = 610 psi kick volume = 10 bbl Hole size = 8.5″ OH x drill pipe capacity = 0.0459 bbl/ft TVD = 10,000 ft OH x drill collar capacity = 0.03 bbl/ft Mud weight = 10 ppg, drill collar length = 600 ft.

OR

Q4) a) Discuss gas influx behaviour in open well migration.                                       [4]

b)        Calculate the vertical height of influx with following data.                       [6]

Hole size = 8.5″ well depth = 11460 ft.

Hole inclination at the bottom = 10°

Drill collars: 6.5″, 2-5/8″ ID, 360 ft OH x Drill collar capacity = 0.0289 bbls/ft OH x Drill pipe capacity = 0.04511 bbls/ft Pit gain = 28 bbls.

c)        Discuss causes of kick and positive kick signs in brief.                              [6]

Q5) a) Accumulator bottle capacity = 10 gallons                                                            [6]

Number of bottles = 20 Max. operating pressure = 3000 psi Minimum operating pressure = 1200 psi Pre-charge pressure = 1000 psi

During BOP function the pressure on the accumulator bottle bank drops from 3000 psi to 1700 psi. How many gallons of fluid did that function use?

b) Discuss the functions of BOP accumulator components.                            [10]

i)             Hydro electric pressure switch

ii)           Hydro pneumatic pressure switch

iii)        Four way valve

iv)         Manifold regulator

v)            Accumulator pressure relief value.

OR

Q6) a) Discuss procedure to test pipe ram (BOP pressure test) after installation of BOP or nipple/up BOP on casing head with suitable sketch. [8]

b) Write short note on :                                                                                                                                       [8]

i)             Bit float.

ii)           Mud gas separator.

iii)        Diverter.

iv)         IBOP.

SECTION2-2II

Q7) a) Discuss wait and weight method of well control in detail.                                [8]

b)        Discuss well control considerations for horizontal wells and associated problems in detail.                                                                                                                    [8]

OR

Q8) a) Prepare kill sheet for following well data.                                      [16]

Hole size = 8.5″ inch, Hole depth = 11962 ft/10892 ft

Casing 13 5 set at 9537 ft/9472 ft

Drill pipe 5″ inch, capacity 0.0176 bbl/ft.

HWDP 5″ inch, 484 feet long, capacity = 0.0088 bbl/ft Drill collar 6.25″ inch, 720 feet, capacity = 0.007 bbl/ft Mud density = 14.5 ppg.

Capacities

Drill collar in open hole 0.0322 bbl/ft Drill pipe/HWDP in open hole 0.0447 bbl/ft Drill pipe/HWDP in casing 0.0493 bbl/ft Mud pump displacement = 0.0109 bbl/stroke Slow circulating rate = 720 psi at 30 spm Fracture mud weight at casing shoe 16.9 ppg Kick data

SIDPP = 550 psi SICP = 783 psi Find

i)             Initial Maasp

ii)           Drill string volume

iii)         Open hole volume

iv)         Total annulus volume

v)            Total well system volume

vi)          What is the pressure safety margin at casing shoe with the well shut in?

vii)       Kill mud density

viii)    ICP and FCP

Q9) a) How to identify following unusual situations plug bit nozzle, washed out bit nozzle, plugged choke, washed out choke or choke manifold. [8]

b)        It was decided to reduce the mud weight from 12.4 ppg while tripping in the well of 9980 ft TVD, string was run to 5950 ft and original mud was displaced by 10.7ppg mud.  [4]

i)              What will be bottom hole pressure now?

ii)           When string was run down to bottom the entire well was displaced by 10.8 ppg mud

Calculate BHP in static condition.                                                                  [4]

c)         Write short note on underground blow out.

OR

QI 0) a) A well is being using wait and weight method at 30 spm with following data.    [4]

Well depth : 9000 ft, SIDPP = 400 psi SICP = 600 psi Original mud : 11ppg

After 1000 strokes, pump speed changed from 30 spm to 40 spm keeping casing pressure constant. What will be the pumping pressure now? Ignore any annular pressure losses.

b)        Discuss in brief snubbing operation.                                                              [8]

c)        What is “bull heading”?                                                                                    [4]

QII) a) Discuss subsea BOP stack with suitable sketch.                             [9]

b) Describe kick prevention and detection in deep water floater ring. [9]

OR

Q12) Write short notes on :                                                         [18]

a)        Hydrate formation 8 prevention

b)        Choke line friction.

c)        Riser booster pump.

d)        Volumeric kill lubrication method.

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