Drilling Definitions :
1. Gin Pole - An “A” frame structure located at the top of standard derricks used to list and lower the crown block into position.
2. Water Table -The water table is the walk-around at the top of standard derricks which supports the crown block.
3. Crown Block - A series of sheaves affixed in the top of the derrick used to change the direction of pull from the drawworks to the traveling block.
4. Derrick - Vertical structure that allows vertical clearance and strength to raise and lower the drill string. This structure with-stands two types of loading: compressive loading and wind loading.
Types of Derricks:
Triple- has the capacity of pulling 90’ stands of pipe
Double- has the capacity of pulling 60’ stands of pipe
Single- has the capacity of pulling 30’stands of pipe (one 30-ft joint)
Standard Derricks - Four sided structures that must be assembled and disassembled when transporting.
Portable Derricks - Telescoping and jackknife types. The telescoping derrick is raised and lowered in an extending and collapsing fashion and lowered in one piece, but may be disassembled to some degree after being lowered
5. Stand - A stand generally consists of two to four joints of made-up drill pipe. The stand is generally used when running or pulling the drill string in and out of the hole.
6. Monkey board - (Stabbing board) The platform on which the derrick man works when tripping pipe.
7. Racking Fingers - Fingers or members where the stands are racked and secured while tripping pipe.
8. “A” Frame - The “A” frame structure on a jackknife used to raise and lower the mast. It also supports the derrick in the raised position.
9. Bull line and Sheaves - The large line and sheaves located on the “A” frame of a jackknife used to raise and lower the derrick.
10. Traveling Block - The block and tackle which is rigged with the crown block by multiples of drilling line strung between the crown block and the traveling block. The efficiency, En, can be computed as
En = 0.98n
where
En is the overall hoisting efficiency
n is the number of lines strung between the crown block and travelling block, and (in this case)
0.98 is the efficiency of each sheave
11. Swivel - That part of the drill sting which connects the rotary hose to the drill string and allows circulation and rotation at the same time.
12. Kelly - The square or hexagonal member at the upper most part of the drill string (immediately below the swivel) that passes through a properly fitting bushing known as the kelly bushing or drivebushing. The drive bushing transmits rotary motion to the kelly which results in the turning of the drill string.
13. Kelly Bushing/Drive Bushing - That bushing which fits inside the rotary bushing and transmits rotary torque to the kelly.
14. Rotary Bushing - The bushing that fits inside of the rotary table opening. This is where the drill pipe and collar slips seat when the drill string is suspended from the rotary table for connections or tripping pipe.
15. Rotary - Transmits the rotary motion or torque from the power source to the drive bushing.
16. Kelly Cock - Safety valves located above and/or below the kelly. These valves are of a ball type and must be manually operated. Their primary purpose is to prevent flow up the drill string in case of emergencies. A third kelly cock is generally kept on the drill floor to be used in the drill string in the event flow up the drill string occurs while making a connection or tripping pipe.
Kelly Cock - Safety valves located above and/or below the kelly. These valves are of a ball type and must be manually operated. Their primary purpose is to prevent flow up the drill string in case of emergencies. A third kelly cock is generally kept on the drill floor to be used in the drill string in the event flow up the drill string occurs while making a connection or tripping pipe.
17. Inside POB Valve - This valve is also used to prevent flow up the drill string when the well kicks and a connection or tripping operations are under way. This valve operates like a check valve and is always kept in open position on the rig floor. This valve is required to be on the rig floor in the open position for Federal leases.
18. Kelly Saver Sub - A sub located blow the lower kelly cock valve. The function of this sub is to prevent wear on the kelly’s threads and to centralize the kelly by means of a rubber protector, thus preventing wear on the kelly’s hexagonal or square shape.
19. Elevators - The elevators are used for latching on to the tool joint or lift sub of the drill pipe or drill collars. This enables the lifting and lowering of the drill string while making a trip. The elevators are connected to the hoisting system (traveling block) by means of bails.
20. Bails - The bails connect the traveling block and elevators. They are solid steel bars with eyes at both ends.
21. Hook - The hook is located beneath the traveling block. This device is used to pick up and secure the swivel and kelly.
22. Slips - Latch around the drill pipe and seat in the rotary bushing in the rotary table. The slips support and transmit the weight of the drill string to the rotary table while making a connection or tripping pipe.
22. Slips, cont. -
A. Drill Pipe
B. Drill Collar
C. Casing
23. Drawworks - The principal parts of the drawworks are the drum, the drum brakes, transmission, and cathead.
- The principal function is to convert the power source into a hoisting operation and provide braking capacity to stop and sustain the weights imposed when lowering or raising the drill string.
A. the drum is housed in the drawworks and transmits the torque required for hoisting and braking. It also stores the drilling line required to move the traveling block the length of the derrick.
C. The drawworks contains all of the controls to divert the rig power to needed operations.
24. V-Door Ramp - The ramp which connects the “V” door to the cat walk.
25. Sandline - The sandline is a small drawworks system. The line is generally used for running surveys or fishing for lost surveys. These units are usually integral parts of the drawworks.
26. Kelly Spinner - A pneumatic operated spinner located above the kelly. It is used to spin the kelly to make up tool joints when making connections. The kelly spinner can generally spin clockwise to speed up connections.
27. Tongs - Large wrench-like devices that are used to tighten up and break out tool joints or connections. The tongs are connected to the break out and make up catheads. Hydraulic tongs are generally used to make up casing and tubing, deriving power from a hydraulic unit.
28. Auxilliary Brakes - The drawworks generally have two braking systems; the band-type brakes on the drawworks drum, and the auxiliary brakes. The auxiliary brakes are used only when going in the hole on a trip. These are used to prevent burning the band-type brakes. The auxiliary brakes are of two types: hydro-dynamic or electromagnetic.
A. The hydro-dynamic type braking is provided by water being impelled in a direction opposite to the rotation of the drum. The brake is mounted on a shaft that can be engaged to the drawworks.
B. The electromagnetic type braking is provided by two opposing magnetic fields. The magnitude of the magnetic fields is dependent on the speed of rotation and the amount of external excitation current supplied. In both types of auxiliary braking systems, the heat development must be dissipated using a liquid cooling system.
29. Deadline Reel and Clamp - The drilling line strung through the traveling block and to the drawworks is secured by the deadline, which is wrapped around the deadline reel and clamped. This prevents the line from slipping and the traveling block from falling.
30. Mud Pumps - Mud pumps are used for circulating the drilling fluid down the drill pipe and out of the annulus. These are high-pressure and high-volume pumps. They can be double-acting duplex pumps or single-acting triplex pumps.
A. The double-acting duplex pump has four pumping actions per pump cycle.
B. The single-acting triplex pump has three pumping actions per pump cycle.
31. Shale Shaker - The shale shaker is a contaminant removing device. It is used to remove the coarser drill cuttings from the mud. This is generally the first solids-removing device and is located at the end of the flow line. The shale shaker is composed of one or more vibrating screens though which mud returns pass.
32. Desander - Desilter- The desander and desilters are for contaminant or solids removal purposes. These devices separate sand-size particles from the drilling mud. Both devices operate like a hydrocyclone. The mud is pumped in at the top of the cyclone. This causes the mud stream to hit the vortex finder which forces the mud down the cyclone in a whirling fashion towards the apex of the cyclone.
The heavier particles are forced outward faster than the smaller particles. The heavier particles on the outside of the whirling fluid are deposited out of the apex while the much smaller particles follow the path of the liquid and reverse their path in the center and flow out of the cyclone through the vortex finder.
If used as a desander or desilter, the waste product is deposited at the bottom and the fluid moving trough the vortex finder is returned to the active system. If used as a clay ejector, the under-flow contains barite particles which are returned to the mud system, while the fluid moving out of the vortex is deposited as waste.
The difference between the various operations of the desander, desilter, and clay ejector relate to the size of the cyclone.
Cyclone Size
Desander 6” or larger
Desilter 4” or larger
Clay Ejector 2” or larger
33. Decanting Centrifuge - A solids-control device which consists of a rotating cone- shaped drum which has a screw conveyer attached to its outer surface. Rotation of the cone creates a centrifugal force that throws the heavier particles to its outer housing.The screw conveyer moves the separated particles to the discharge.
This device has to be monitored closely in a water-based mud because it allows discharge of bentonite (gel). The bentonite controls viscosity and fluid loss. If allowed to operate for long periods of time without adding bentonite to the mud system, filtration control will be lost.
34. Degasser - This vessel is used for gas contamination removal. It consists of a vessel which has inclined flat surfaces in thin layers and a vacuum pump. The mud is allowed to flow over the inclined thin layers which helps break out entrained gas in the mud. The vacuum pump reduces the pressure in the vessel to about 5 psia which extracts the gas from the mud. This device is about 99% efficient.
35. Mud Gas Separator - This is generally the first device available to extract gas from the mud. It consists of a tower with baffle plates, which are flat plates that force the fluid through a certain path. The mud is allowed to flow in the tower over the baffle plates which separates some of the entrained gas. This device generally can extract 50% to 60% of the gas.
36. Accumulator - The accumulator is a hydraulic system that maintains and stores enough high-pressured fluid to operate every function of the blow-out preventors (BOP’s) at least once and still have a reasonable reserve, as defined by the governing agency rules. The system has a pump which pumps the hydraulic fluid into storage bottles.
The storage bottles have floats which separate the hydraulic fluid from the gas (nitrogen) in the upper part of the chamber. As fluid is pumped into the chamber bottles, the gas is compressed, resulting in the pressure needed to move the hydraulic fluid to operate the BOP’s.
37. Bag-Type Preventers (Annular Preventers)
This preventer is used the most because the rubber sealing element can conform to any shape or size conduit in the hole. The annular preventer can further collapse completely and seal the annulus with no conduit to the hole. (This is not recommended.)
The annular preventers consist of a rubber-covered, metal-ribbed sealing element. This element is caused to collapse and seal by allowing the pressurized hydraulic fluid from the accumulator to move a tapered, form-fitted cylinder against the rubber which causes collapse.
A. Real rubber sealing elements which wear much longer but should not be used with oil-base muds or known oil fields because of the adverse effect of the oil on the rubber.
B. Synthetic rubber sealing elements which do not last as long as the real rubber, but can be used with oil-base muds or in known oil fields.
38. Ram Preventers - This type BOP is used mainly as a backup to the bag-type preventer or for high-pressure situations.
A. The pipe rams have two rams on opposite sides that close by moving towards one another. The rams themselves have semicircular openings which match the diameter of pipe being used. Each different size pipe requires correctly sized rams.
B. If a tapered string is being used to drill a well, such as a 5” drill pipe and a 3-1/2” drill pipe, then two ram-type preventers must generally be used. This type preventer cannot allow the pipe to be worked through it.
C. The blind rams do have the semicircular opening of the pipe rams. Instead, the front surface of the blind rams is flat, and they can only be used to seal the annulus when there is no pipe in the hole.
D. The shear blind rams are designed to cut through the drill pipe and seal the hole. this type of preventer should only be used as a last resort.
39. Diverter System - The diverter system is 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.
This system generally consists of a drilling spool with two 4” outlets. Attached to the outlets is a valve or valves which connect to a line leading away from the rig.
40. Choke Manifold- This is a system of valves and lines which are attached to the choke line, and in some cases, kill line. The manifold is used to help control a well that has kicked by diverting the flow to various functions such as an adjustable choke. It is designed for versatility in diverting the mud flow after experiencing a kick.
41. Adjustable Choke - The adjustable choke is usually hydraulically controlled from a remote panel located on the rig floor. The purpose of the adjustable choke is to hold the correct back pressure on a well when controlling a kick so as not to allow any more formation fluid into the hole and/or prevent breaking the formation down while controlling the well.
42. HCR Valve - the HCR valve is a hydraulically operated gate valve. This valve is used on diverter systems and choke lines leading from the blow out preventers. The advantage of the valve is that it can be operated remotely.
43. Float - The float is a check valve run in a special sub in the bottomhole assembly. It prevents any back-flow up the drill pipe. This should be run in shallow drilling operations to help control “shallow” kicks.
44. Underreamer - The underreamer is to increase the diameter of the hole without running a full gauge tool into the hole. It is hydraulically operated. As the pump pressure increases, a piston inside is driven down, thus forcing three arms with cones to extend. With arms extended, the hole can be opened to the designated size.
45. Hole Opener - The hole opener serves the same purpose as the underreamer, which is to enlarge the previously drilled hole. Unlike the underreamer, the hole opener is full-gauged.
46. Rat Hole - The steel casing extending below the rig floor where the kelly and swivel are stored while tripping.
47. Mouse Hole - A section of steel casing that extends below the rig floor where drill pipe is placed to be made up in the drill string or to the kelly. It is further used in laying down drill pipe. The joint of drill pipe is broken off in the mouse hole, picked up with the sir hoist or catline, and moved out the V-door down to the catwalk.
48. Drill Collars - The drill collars are thick-walled heavy steel tubulars used to apply weight to the bit. The drill collars should take all of the compressive loading, leaving the drill pipe in tension.
49. Drill Pipe - The major part of the drill string is composed of drill pipe. Drill pipe is hot-rolled, pierced, seamless tubing. Drill pipe is specified by its outside diameter, weight per foot, steel grade, and range (length). The drill pipe transmits rotation, vertical movement and drilling fluid to the bit.
50. Heavyweight Drill Pipe - Thick-walled heavy drill pipe is used in lieu of drill collars. It is generally used in high-angled well where too many drill collars hamper drilling operations.
51. Standpipe - The standpipe is that pipe which carries mud from the rig floor into the derrick to the kelly hose. It must be pressure-tested to the working pressure of the BOP’s.
52. Kelly Hose - The kelly hose is a section of high-pressured hose connecting the standpipe and the swivel. The kelly hose allows for the vertical movement of the drill string as well as circulation of fluid down the drill string.
53. Substructure - the substructure provides the support for the derrick and derrick loading. It also provides the necessary clearance beneath the rig floor for he preventor stack.
54. Keyway - The keyway is the opening on an inland barge or offshore jackup in which the drilling operations are performed.
56. Moonpool - The hole through a floater or semi-submersible structure is which the drilling operations are performed.
57. Motion Compensator - A pneumatic, hydraulic surface unit that compensates for the heave of a drillship or semi-submersible. This allows the drill string and bit to remain stationary with respect to the earth.
58. Bumper Subs - The bumper sub is a downhole motion compensator. It operates as a slip joint. Most bumper subs have a 3-5 feet stroke and can be run in tandem for motion exceeding 3-5 feet. The bumper sub is used on floating operations to reduce the heaving motion of drillships or semi-submersibles on the bits.
A disadvantage of the bumper sub is maintenance costs both for the tool itself and lost time due to tripping pipe when one fails. Furthermore, the position of the bumper sub is not ever really known while drilling operations are being carried out, so its effectiveness can be limited.
59. 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.
60. Cat Walk - The cat walk is where the pipe is laid down from the drill floor. Any elevated walkway may be referred to as a catwalk.
