FE 02-06 Well Control Components

Nội dung text: FE 02-06 Well Control Components

1. Well Control Equipment: Function • Close the well and control a kick before it becomes a blowout
2. Blowouts Are Dangerous • It endangers lives • Destroys the rig • May damage the environment
3. Blowouts
4. Kill A Well • To stop a well from flowing or having the ability to flow into the wellbore
5. BOP Stack
6. Major Changes in BOP Equipment for Subsea Use • The size of the BOPs is increased. • External hydrostatic pressure at the ocean floor must be considered. • Hydraulics have become more important in reaction times, because the longer flow lines increase the pressure drop, while the larger BOPs require more fluid to operate than their land counterparts.
7. Annular Preventer • Has a rubber sealing element that, when activated, closes tightly around the kelly, drill pipe or drill collars or the open hole (if there is no pipe in the hole) • Always at the top of the BOP stack
8. Pipe Rams • Pipe rams close on the drill pipe and are not able to effect a seal on an open hole.
9. Shear Rams • Shear rams are blind rams that have a cutting edge to cut the drill pipe completely, thus sealing the hole. They are used mainly in subsea systems.
10. Rotating BOP • Also called a rotating head or a stripper head • They are continuously closed around the drill stem by means of a heavy-duty stripper rubber that rotates with the drill string. Packing provides a seal between the rotating and stationary elements. • Useful in drilling with air, gas, foam or any other drilling fluid whose hydrostatic pressure is less than the formation pressure
11. Accumulator • Several bottle- or ball-shaped containers where hydraulic fluid, are stored under a pressure-regulated system • Capable of supplying sufficient high pressure fluid to close all the units in the BOP stack at least once and still have reserve • Located at least 100 feet from the BOP stack
12. Choke System • A series of valves, chokes, gauges and lines that is connected that controls the rate of flow from the well when the blowout preventers are closed • When the well is shut in, the kick is circulated out through the choke line and manifold • 2 types: – Adjustable chokes: opening controlled hydraulically – Fixed chokes: flow restriction of permanent size
13. Kill Line • A high-pressure conduit from an outlet in the BOP to the rig’s mud pumps and used to pump fluid into the annulus from the top of the well if the drillpipe is not accessible.
14. Diverter System • Used in conjunction with the annular preventer to divert the path of mud flow either overboard or through the mud gas separation facilities. • This system is generally only used when drilling at shallow depths where the formation has a weak fracture gradient. Flowline Control Valve
15. Nipple Up and Nipple Down • Nipple Up – to assemble the BOP’s after a nipple down operation • Nipple down – to disassemble the BOP’s
16. Snubbing • Similar to stripping except that the string is “pushed” (snubbed) back into the wellbore; whereas in stripping, the pipe “falls” into the hole by its own weight
17. Installing a Subsea BOP 3. The 30” casing is run and set. PGB and wellhead housing are also run. The subsea wellhead is attached to the top of the conductor casing. The wellhead assembly latches into the guide base structure. NOTE: Sometimes the 30” casing is jetted or driven in - instead of being drilled. NOTE: The guide posts on the permanent guide structure. These are for the BOP stack
18. Pods and Control Lines • The pods and control lines are used in subsea operations; the control lines run from the accumulator to the pods which are located on the subsea BOP stack. These two devices are responsible for transmitting the hydraulic pressure from the accumulator to actuate the various functions of the subsea BOP stack.
19. End of Topic