Bleed off pressure at the unit, not against the plugs.

12.4.4 Launching the bottom plug

Open the bottom valve of the cement head and pump any fluid ahead if necessary.

Stop pumping.

Turn the pin the required number of turns to release the plug.

Open the middle valve and close the bottom valve.

12.4.5 Launching the top plug

After pumping of the cement is

completed, ensure that the pumps on the unit are stopped.

Loosen the tattletail wire seal nut. Turn the pin the required number of turns to release the plug.

If necessary, wash up the lines. Open the top valve.

Close the middle or bottom valve. Slowly start pumping the displacement. Check the tattletale for plug departure. If in doubt of plug departure, review the contingency plan with the company representative, remove the cement head cap, and check for plug departure. After pumping about 5 bbl (800 L) of displacement, open all the valves on the cement head to wash out any cement. 1. 2. 3. 4. 1. 2. 3. 4. 5. 6. 7. 8. 9.

12.4.6 Launching two-stage plugs

Note that the first-stage plug is flexible and should therefore not be preloaded into the head.

Close all the valves on the head. If there is a bull plug on the head to relieve the suction on the cap, knock it off.

Remove the cap.

Place the flexible first-stage plug into the head and force it down as far as possible.

Close the cap (be sure that the O-ring is still in place) and bull plug.

Open the top valve and displace the first-stage cement.

Once the displacement is finished and the pressure is bled off, open the cap and drop the opening bomb.

If the client approves, load the second- stage closing plug according to the top plug loading instructions (see Section 5, Launching the top plug).

Close the cap and continue with the cement job.

12.4.7 Postjob

Either on location or upon returning to the district, prepare for the next job as follows:

If the plug did not bump, open the head to make sure that the plug is not there.

All valves should be left open and the pins retracted. If the head will be left on location, leave the pins inserted to avoid the risk of damage during movement by the rig crew. 1. 2. 3. 4. 5. 6. 7. 8. • •

96 | Appendix

The head should be cleaned inside and outside.

Use a hose to ensure that water flows through all the valves on the manifold. Grease the head.

Check that all O-rings and seal rings are in place and undamaged.

Green-tag the head if everything is in order. If there is still a problem, red-tag it.

12.4.8 Additional information/precautions

Cement heads should be painted Schlumberger blue, with the working pressure (clearly stating units) and size painted in white, and at least 1 in high. The valve indicators should also be painted white (to clearly show the direction of the valve).

It is recommended to chain a valve bar to the manifold to avoid the bar being dropped into the hole or annulus or on to the rig floor.

If there is a change in plug supplier, ensure that the new plugs completely pass through the head with a minimum amount of force and that they cannot pass by the extended pins.

As a minimum the cement head should be pressure tested to its working pressure once a year. The manifold and body should be thickness tested as specified in Standard 14, Section VI.

Review Maintenance Bulletin 1062A for the twin path slings.

Review Maintenance Bulletin 1100 for issues regarding the internal chamfer on some IRI heads.

Review Maintenance Bulletin 984 and 1056 for pull pin checks and maintenance.

• • • • • •

For additional information about products, you can contact the following:

FMC

FMC Stephenville, Texas Sonja Brown

E-mail: [email protected] IRI

Industrial Rubber, Inc. Bob Chaney

E-mail: [email protected] TOT

Texas Oil Tool Bryant Cardwell

E-mail: [email protected] Grant Oil Tools

Smith Services, Drillco Group E-mail: [email protected] Woods Machine

Woods Machine, Tulsa, OK E-mail: [email protected] UIE

UIE, Montpellier, France Fax # 467-83-51-79 Dayco

Fluid Specialties, Tulsa, OK E-mail: [email protected] Bishop Lifting Products, Inc. 1410 Harris Street, P.O. Box 15619 77220, Houston, Texas, USA Email: [email protected]

13.0 Check Your Understanding

1. Arrange the steps in a cement job in order:

___A. Prepare the casing.

___B. Drop the top plug.

___ C. Drop the bottom plug.

2. What are the functions of the plugs? A. to separate fluids and prevent

contamination

B. to clean the casing wall

C. to provide a surface indication at the end of displacement

D. all of the above

3. What are the two types of cement heads currently used in Schlumberger?

A. fabricated B. integral C. united

4. What is the pressure rating for a single plug fabricated 9-5/8-in cement head? A. 1,500 psi

B. 3,000 psi C. 5,000 psi

5. Match the appropriate name of each component with the number:

1 2 3 4 5 6 7 1. ___ A. cap 2. ___ B. manifold assembly 3. ___ C. bull plug 4. ___ D. plug release 5. ___ E. quick coupler 6. ___ F. bull plug 7. ___ G. 2x2 integral plug valve

98 | Check Your Understanding

6. What is the definition of the tattletale? A. The top-sealing device of the cement

head. In a double-plug cement head, both top and bottom plugs are loaded into the cement head before starting the job.

B. A type of release. It must be retracted a specific number of turns to enable the wiper plug to move downward.

C. A physical indicator. It shows the operator that the plug has left the cement head.

7. If the tattle-tail of the twin path slings does not extend past the black line, which of the following actions should be taken?

A. Fix the tattle tale.

B. Remove the sling from service. C. Red tag it.

8. What three factors must be taken into account when choosing the cement head and adapter for the job?

A. casing size B. size of the plug C. casing thread D. bail size

E. all of the above

9. What distinguishes a top plug from the bottom plug?

A. color

B. the top plug is solid; the bottom plug is hollow

C. size

D. material used

10. What is the state of the tattletale? Match the figure number with the appropriate sentence:

A. ___ B. ___

1. The tattletale lever prior to plug departure

11. When leaving the district, the plug valves should be in which position?

A. bottom valves shut; top valves in open position

B. top valves shut, bottom valves in open position

C. bottom valves open, middle valves closed, top valves in open position D. none of the above

12. How often are the cement head and the quick couplings tested for optimum performance?

A. every 12 months B. every 3 months C. after every job

13. What is the correct pin-puller installation? A.

B.

14. Match the thread to the name: A. ___ buttress

B. ___ round

15. The primary function of the _________ is to enable the casing to be tripped in with relative ease, preventing jamming in washed-out zones or deviated wells. A. guide shoe

B. float collars C. centralizers D. bull pin plug 1.

100 | Check Your Understanding