IWCF Comb. Supv Equip. 02.doc

IWCF COMBINED SUPERVISOR EQUIPMENT PAPER NO. 2. Name:

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Date:

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Start time:

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Finish time:

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Mark:

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Percentage Mark:

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Training Centre Name:

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Invigilator Name:

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Invigilator Signature:

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Duration:

One hour (1 hour)

Total paper value:

164 marks

All questions require only ONE answer unless otherwise stated.

1

1:

Why are Variable Rams not used exclusively in place of positive bore rams on sub sea stacks? a.

Hang-off is not possible with variable rams.

b.

It is not recommended to strip through variable rams.

c.

Variable rams must be replace after each well.

d.

Variable rams have serious temperature limitations. 1 mark

2:

An automatic riser- fill-up valve is often fitted to the riser. The purpose of this device is that: TWO answers required. a.

It will automatically open if there is a considerable reduction in the density of the mud in the riser.

b.

It will automatically open if there is a reduction in fluid level in the riser due to lost circulation.

c.

It will help in disconnecting the riser.

d.

It can be used as a mud booster. 3 marks

3:

What is the API RP 53 recommendation for the fluid reservoir capacity of a BOP accumulator control unit on a sub sea installation? a.

2 times the total accumulator bottle capacity

b.

2 times the usable fluid capacity of the accumulator capacity.

c.

4 times the required volume of all the BOP functions.

d.

Enough volume to close, open and close all the BOP Functions. 1 mark

2

4:

From the list below select the methods for determining the choke line pressure drop on deep water floating rigs. THREE answers required. a.

Circulate up the riser and record SRC pressure. Close the BOP and circulate at the same rate up the choke line. Record the difference between the two pressures as choke line friction.

b.

Circulate up the riser and record SRC pressure. Close the BOP and circulate at the same rate up the choke and kill lines. Record the difference between the two pressures as choke line friction.

c.

Circulate up the riser and record SRC pressure. Close the BOP and circulate at a reduced rate up the choke line. Record the difference between the two pressures as choke line friction.

d.

Pump down the choke line and up the riser.

e.

Pump down the kill line and up the choke line. Divide the recorded pressure by 2.

f.

Pump down the kill line and up the choke line. Divide the recorded pressure by 4. 4 marks

5:

There are several accumulator bottles on a frame on the sub sea B.O.P. stack. These bottles will be pre-charged with nitrogen while on surface. The precharge for these bottles will be: a.

The same as the surface bottles

b.

The same as the surface bottles plus seawater hydraulic pressure

c.

The same as the surface bottles minus seawater hydraulic pressure

d.

The same as the working pressure of the surface accumulator hydraulic pressure 3 marks

3

6:

Before a 10,000 psi BOP stack is initially accepted and brought into the field for work, it must have a body shell test of: a.

100 % of its rated capacity.

b.

125% of its rated capacity.

c.

150 % of its rated capacity.

d.

200 % of its rated capacity. 1 mark

7:

Select from the following list, which are API Recommendations for periodic field testing of BOPs. THREE answers required. a.

After setting casing

b.

After circulating out a kick

c.

Once a month

d.

After repairs to the stack.

e.

After every 1000 ft. drilled

f.

Prior to entering a known transition zone. 4 marks

8:

While performing a pressure test on a Surface Stack the test pressure should be limited: a.

To the rated pressure of the Wellhead and the BOP.

b.

To the rated casing burst pressure 1 mark

9:

The BOP's are sitting in the set back area prior to rippling up on a well. According to the API recommendations what should they be tested to before they are nippled-up? a.

75% of the rated pressure

b.

50 % of the rated pressure 4

c.

100% of the rated pressure

d.

125% of the rated pressure 1 mark

10:

Why is it important to vent a test plug at surface when testing the BOP's? a.

To help seat the test plug

b.

In order not to damage the casing and formation

c.

To assist the test plug to seal

d.

So the test string can be pulled dry when pulled out of the hole after testing. 3 marks

11:

If a pressure test were to be performed on a surface stack using a cup-type tester; would this have an effect on the hook-load? YES

NO 1 mark

12:

Referring to question 11 above would the hook load increase as pressure is increased, or would the hook-load decrease? INCREASE

DECREASE 3 marks

13:

When a BOP function is operated from the sub sea BOP control panel, which of the following is true? a.

SPM valves will operate in both pods.

b.

SPM valves will operate only in the active pod.

c.

The shuttle valve will operate first. 2 marks

14:

When a close BOP function is operated from the sub sea BOP control panel, which of the following is true? a.

The open SPM valve vents back to the tank. 5

b.

The open SPM valve will move to the block position.

c.

The open SPM valve vents to the seabed. 4 marks

15:

In order to verify the actual pressure supplied to an annular or ram preventer on a sub sea stack, a read-back signal is returned to the control panel at surface. Where is the signal sent? a.

Upstream of the regulator in the pod.

b.

The regulator itself.

c.

Downstream of the regulator in the pod. 4 marks

16:

From what direction should a valve on the choke and kill manifold be tested? a.

Always from the upstream side.

b.

From the direction fluid would be expected to come from in a well control situation.

c.

Always from the downstream side.

c.

It does not matter, as valve is made to test on both sides. 2 marks

17:

Below are three types of valves that would be found in a subsea BOP system, identify the type of valve that is located on the accumulator control unit. 4 marks a. MANIPULATOR VALVE. (manually or pneumatically operated).

b.

Fig. 1 SELECTOR VALVE. (manually operated). 6

c.

18:

Fig. 2 SPM VALVE. (sub-plate mounted). Fig. 3

Refer to the fig. 1 on the previous page; select the correct statements from the list below. THREE answers required. a.

The valve has 4 active connections.

b.

The valve can be put into 4 different positions.

c.

The valve is hydraulically operated.

d.

Cycle 1 and 2 are vented in the block position.

e.

The valve can be operated manually.

f.

The actuator is spring loaded. 4 marks 7

19:

From the statements regarding ring gaskets listed below identify the correct statements for those gaskets that may be used from flange to flange. TWO answers required. a.

Type RX and BX ring gaskets provide a pressure-energised seal.

b.

The same material specifications apply to ring gaskets as to ring grooves.

c.

Ring gaskets may be used several times.

d.

Type BX flanges that are designed for face-to-face make up use type BX ring gaskets only. 3 marks

20:

On a surface BOP stack, a small fluid volume is required to operate the hydraulic valves on the BOP side outlets. At the Driller’s remote panel, the Driller pushes MASTER and CHOKE OPEN simultaneously. He observes that the red light goes out and the green light comes on. Do the lights confirm that the choke line valve is in an open position? Yes

No 2 marks

21:

The figure below shows an LMRP (Lower Marine Riser Package) an integral part of a sub sea BOP. Match the items listed below to the numbers on the drawing.

8

1 mark for each correct answer.

22:

a.

Flexible choke/kill loop.

b.

Flexi joint.

c.

Control pod.

d.

Riser connector.

e.

sub sea accumulator bottles.

f.

Annular preventer.

g.

Shuttle valve.

h.

Hose bundle.

If a well kicks with the bit off bottom and is shut in. A decision is made to strip back into the hole. Prior to performing the stripping operation safely, how should the Full Opening 9

Safety Valve and the Inside Blow Out Preventer be made up in the string. a.

Only the Full Opening Safety Valve in closed position.

b.

Only the Inside Blow Out Preventer.

c.

Full Opening Safety Valve (open) with Inside Blow out Preventer installed on top.

d.

Inside Blow Out Preventer with Full Opening Safety Valve (closed) on top.

e.

Only the Full Opening Safety Valve (open) 3 marks

23:

From the list below select the correct statements regarding annular BOP’s. THREE answers required. a.

They are a means of secondary well control.

b.

They are designed to seal around any object in the well bore.

c.

They cannot seal on a square or hexagonal Kelly.

d.

They will not allow tool joints to pass through.

e.

They will allow reciprocating or rotating of the drill string while maintaining a seal against well bore pressure.

f.

They can require a variable hydraulic closing pressure according to the operation carried out. 4 marks

24:

Before the installation of any annular packing element, which of the items listed below have to be checked: TWO answers required. a.

Minimum pipe outside diameter.

b.

Temperature rating of the element. 10

c.

Type of mud to be used.

d.

Desired hydraulic closing pressure.

e.

Maximum pipe outside diameter. 3 marks

25:

Most front packer elements fitted on BOP rams are enclosed between steel plates. What are the reasons for this. TWO answers required. a.

To protect the ram rubber.

b.

To support the weight of the drill string during hang-off.

c.

To prevent damage to the rubber between the pipe and ram blocks when wellbore pressure is applied.

d.

To extrude elastomer into sealing contact with the pipe when the sealing face becomes worn.

e.

To prevent any swelling when in use during high temperature operations. 3 marks

26:

What is the purpose of the Hi/Lo bypass control on the Driller’s remote control panel on a surface BOP stack. a.

To increase the annular pressure to existing accumulator pressure.

b.

To increase the manifold pressure to existing accumulator pressure.

c.

To increase the manifold pressure to 2,000psi.

d.

To increase the accumulator pressure to 3000psi. 3 marks

27:

"Blow-Down" lines are found a.

Upstream of the choke.

b.

Downstream of the choke.

c.

On the standpipe manifold.

d.

At the shakers. 2 marks 11

28:

The liquid in a MGS is used to determine; a.

The maximum operating pressure within the MGS.

b.

The minimum pressure within the MGS. 3 marks

29:

What is the function of the Pod Select Valve? a.

To vent the redundant pod.

b.

To direct power fluid to the active pod.

c.

To direct pilot fluid to the active pod.

d.

To operate the BOP function. 3 marks

30:

What effect does the operation of the pod select valve have on the pilot system? a.

It has no effect on the pilot system.

b.

The pilot system is automatically vented.

c.

Full power fluid pressure is applied to the pilot system.

d.

The pilot system is blocked automatically. 3 marks

31:

An accumulator bottle at surface has a pre-charge pressure of 1,000 psi. The pressure gradient for seawater is 0.445 psi/ft. If used as a subsea bottle in 1,170 ft. of water what will be the correct pre-charge pressure? Answer

psi. 3 marks

32:

When a sub sea annular preventer is closed which of the following statements indicate that the function has taken place. FOUR answers required. a. Light change from Green to Red. 12

b. Accumulator pressure decreases then increases. c. Rig air pressure decreases then increases. d. Manifold readback pressure decreases then increases. e. Manifold Pilot pressure decreases then increases f. Annular readback pressure decreases then increases. g. Annular Pilot pressure decreases then increases. h. Flowmeter runs then stops after the required volume of fluid. 5 marks 33:

According to API-RP 53, the Diverter system is designed to open one or more vent lines prior to closing the Diverter. True

False 2 marks

13

34:

Figure Alert 086 below shows an API example of a Diverter with an Insert-Type Packer. Match the numbers to the items listed below.

Alert 086 1 mark for each correct answer. Diverter Lockdown Dogs.

Closing Port.

Insert Packer.

Insert Packer Lockdown Dogs.

IADC WellCAP Comb. Supv. Equip. Feb. 04

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Support Housing.

35:

Standard Packer.

From Figure Alert 017a below, when this preventer is used in a subsea operation, which of the statements below are correct. TWO answers required.

Alert 017a

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a. The lowest required closing pressure is when the closing chamber and balancing chamber are connected. b. The lowest required closing pressure is when the opening chamber and balancing chamber are connected. c. The balancing chamber allows balancing the opening force on the piston created by drilling fluid hydrostatic pressure in the marine riser. 3 marks 36:

From the list, below which statement explains the advantage of using the kill line, open to the wellhead to monitor changes in pressure during a well kill operation? a. Maintaining a constant pressure on the kill line gauge while starting or stopping the pumps compensate for the effect of choke line friction. b. Bottom hole pressure can be accurately monitored by maintaining a constant pressure on the kill line gauge while pumping kill fluid to the bit. c. The effect of choke line friction is reduced to a half when monitoring on the kill line gauge during the kill operation. d. The effect of choke line friction is reduced to a quarter when monitoring on the kill line gauge during the kill operation. 4 marks

37:

The following data is given for a surface installed ram type BOP. Nominal size: Maximum rated working pressure: Closing ratio: Hydraulic fluid volume required for ram:

135/8” 15,000psi. 11.2 : 1 99.8 gallons.

The accumulator bottle data: Accumulator bottle capacity (Nitrogen & Fluid): Accumulator bottle pre-charge pressure: Maximum operating pressure: Minimum operating pressure:

10 gallons (ignore bladder) 1,000psi 3,000psi 200 psi above pre-charge pressure.

Calculate the minimum number of bottles required in the accumulator bank to enable IADC WellCAP Comb. Supv. Equip. Feb. 04

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closing the ram BOP’s on the Full Rated Working pressure of the BOP. Answer

Bottles. 5 marks

38:

What mechanisms are used to close the choke and kill line valves on a sub sea BOP. TWO answers required. a.

Hydraulic motor.

b.

Pneumatic motor.

c.

Spring force.

d.

Hydraulic pressure.

e.

Well bore pressure. 3 marks

39:

Which of the following functions are operated by manifold pressure? a.

Shear rams only.

b.

Pipe rams only.

c.

Annular only.

d.

All BOP functions.

e.

Rams and HCR valves.

IADC WellCAP Comb. Supv. Equip. Feb. 04

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2 marks 40:

When testing a pipe ram at the weekly BOP test you are informed that the "weep hole" on the ram is leaking fluid. What action would you take? a.

The 'weep hole' only checks the closing chamber seals so leave it till next maintenance schedule.

b.

Energise emergency plastic packing ring. If leak stops then leave it till next maintenance schedule.

c.

Primary mud seal is leaking and you should repair immediately.

d.

Ram packing elements on ram body are worn and should be replaced immediately.

e.

A leak here is normal because metal sealing faces in the ram need some lubrication to minimise damage. 5 marks

41:

A BOP stack is made up from the wellhead as follows: Three ram BOP’s, Cameron type U, 135/8 “ 10,000psi rated working pressure. One annular BOP, Hydril type GK, 135/8 “, 5,000psi rated working pressure. After taking a kick the well is closed in on 3½” pipe using the annular BOP, the stabilised closed in pressures on the casing gauge reads 1,550 psi. To what hydraulic pressure should the annular closing pressure be adjusted to meet the manufacturer’s recommendations.

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Answer

psi. 4 marks

42:

The designation 135/8” on an item of BOP equipment designated as 15M - 135/8” refers to which of the following statements. a.

The bore, (nominal size/inside diameter) of the preventer.

b.

The external diameter of the flange of hub.

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c.

The cylinder diameter of the hydraulic actuator for a ram BOP.

d.

The external diameter of the BOP.

e.

The external diameter of the side outlets. 3 marks

43:

From the list below select the statements that are correct regarding fixed bore ram BOP’s. TWO answers required. Ram BOP’s are designed to contain and seal rated working pressure from above the closed rams as well as from below.

d e

b.

Ram BOP’s must be equipped with a mechanical locking system.

c.

Fixed bore ram BOP’s can close and seal on various pipe sizes.

d.

Fixed bore ram BOP’s can be used to hang off the drill string.

e. Ram BOP’s require a minimum operating pressure of 3000psi. 3 marks

44:

Identify the parts of the Cameron Blind/Shear ram in Figure Alert 040 shown below.

IADC WellCAP Comb. Supv. Equip. Feb. 04

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Alert 040

Lower Ram Assembly

Blade Packer

Top Seal

Upper Ram Assembly

Side Packers

Upper Ram Body

1 mark for each correct answer.

IADC WellCAP Comb. Supv. Equip. Feb. 04

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45:

Match the items listed to the number on Figure Alert 015 of a Cameron D annular preventer.

Alert 015 Opening hydraulic ports.

Vent.

Closing hydraulic ports.

Pusher plate.

IADC WellCAP Comb. Supv. Equip. Feb. 04

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Packing element.

Donut.

Operating piston.

Quick release top.

1 mark for each correct answer. 46: Based on the Figure Alert 024 below, with a mud weight of 12.6 ppg flowing through the MGS and liquid seal how much hydrostatic head (back pressure) would have to be overcome to allow gas to vent to the shale shakers if H4 was 14 ft.

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Alert 024 psi. 5 Marks IADC WellCAP Comb. Supv. Equip. Feb. 04

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