Question

a. If a pipe has failed a MIT, what measures can be done next .

b.What follow-up treatment could be required for the MIT failed pipe? Give two.

c. Christmas tree provides both surface pressure control and flow line control’ How this is possible?

d. On opening the gate valve, the flow path is enlarged in a highly nonlinear manner with respect to the opening. Why?

e. Give other shut off applications in oil industry, where ball valves can be used.

Answer 1

a. If a pipe failed in MIT measures can be taken as follows-

1.Appropriate monitoring facilities and safety sytem should be provided

2. Safety zones in both side of the pipeline

3.Increase pipe wall thickness

4.Protection from damage eg. burying the line

b. follow up treatement that can be done-

1.High quality internal pipe coating can be provide

2.CIPP lining can be done

c. Christmas tress has a set of valves including master valve and wing valve , a choke and connections and is installed on the top of the tubing head.It provides a means to control flow of production fluids from the well which serves as the primary purpose of the equipment.It diverts the fluid flow through the wing valve to the flow lines ensuring safety of the facilities.

d. Because the flow doesnot change evenly with stem level.Also a partially open gate disk tends to vibrate from the fluid flow.Most of the flow change occur near shutoff wwith relatively high fluid velocity causing disk and seat wear.

e. Ball have have wide range of shut aplications in all sizes,including HPI,Steam and condensate applications.follwing instruments have ball valves in oil industry which are used in Shut applications-

1.Hand wheel

2.Electric motor

3.Pneumatic aquator

4.Hydraulic aquator