What is kelly bushing elevation?

Kelly Bushing Height (KB): The height of the drilling floor above the ground level. Many wellbore depth measurements are taken from the Kelly Bushing. The Kelly bushing elevation is calculated by adding the ground level to the Kelly bushing height. Rotary Table (RT): e.g. MDBRT or TVDBRT.

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Hereof, what is the kelly bushing?

Kelly Bushing, also known as Drive Bushing, is a drilling device that is used to connect a Kelly with a rotary table. This tool is used to fit inside the head where the Kelly fits.

Furthermore, what is datum depth? Datum depth is the depth measured from surface where the wellbore flowing pressure is measured or calculated at for a multi-layered reservoir.

Beside this, what is the difference between Kelly and kelly bushing?

When drilling, the drill bit is attached at the end of the drill string and thus the kelly drive provides the means to turn the bit (assuming that a downhole motor is not being used). The kelly is the polygonal tubing and the kelly bushing is the mechanical device that turns the kelly when rotated by the rotary table.

What does Tvdss mean?

True Vertical Depth SS

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How does a top drive work?

Top drive. A top drive is a mechanical device on a drilling rig that provides clockwise torque to the drill string to drill a borehole. It is an alternative to the rotary table and kelly drive. The top drive allows the drilling rig to drill the longer section of a stand of drill pipe in one operation.

What is a monkey board?

monkey board n. a small or narrow elevated platform on which a person stands (to operate a vehicle or machinery, or to perform other work).

What is a drilling Kelly?

Drilling] A long square or hexagonal steel bar with a hole drilled through the middle for a fluid path. The kelly is used to transmit rotary motion from the rotary table or kelly bushing to the drillstring, while allowing the drillstring to be lowered or raised during rotation.

What is a saver sub?

Definition of 'saver sub'

A saver sub is a short piece of connecting pipe with threads on both ends, which is part of a drill string. A saver sub is a short piece of connecting pipe with threads on both ends, which is part of a drill string.

What is the rat hole on a drilling rig?

A rathole is a hole in the rig floor, 30 to 35 feet deep, lined with casing that projects above the floor, into which the kelly is placed when hoisting operations are in progress. This is either done by the portable rig that drills the conductor hole or can be done by the primary rig after rigging-up.

What is TVD in oil and gas?

In the petroleum industry, true vertical depth, abbreviated as TVD, is the measurement from the surface to the bottom of the borehole (or anywhere along its length) in a straight perpendicular line represented by line (a) in the image.

What is KB in oil and gas?

1. n. [ Drilling] An adapter that serves to connect the rotary table to the kelly. The kelly bushing has an inside diameter profile that matches that of the kelly, usually square or hexagonal.

What is the difference between MD and TVD?

Difference between True Vertical Depth (TVD) and Measured Depth (MD) True Vertical Depth (TVD) is measured vertically from the surface down to a certain target down hole. Measured Depth (MD) is the total length of the wellbore measured along the actual well path.

What is a Kelly?

A kelly is part of the drill string, and is a six-sided or four-sided piece of pipe that fits tightly into the bushing which is fitted in the rotary table, and rotates the drill bit.

How does a rotary table work on a drilling rig?

A rotary table is a mechanical device on a drilling rig that provides clockwise (as viewed from above) rotational force to the drill string to facilitate the process of drilling a borehole. Rotary speed is the number of times the rotary table makes one full revolution in one minute (rpm).

What is Swivel in drilling?

A Swivel is a mechanical device used on a drilling rig that hangs directly under the traveling block and directly above the kelly drive, that provides the ability for the kelly (and subsequently the drill string) to rotate while allowing the traveling block to remain in a stationary rotational position (yet allow

What is true vertical depth in drilling?

True Vertical Depth (TVD) This is the vertical distance from the wellhead to a point in the wellpath. This quantity is calculated from the directional survey data. Note that a measured depth, due to the wellbore curvature, is always greater than the corresponding true vertical depth. It is commonly referred as TVD.

What does TVD mean in drilling?

true vertical depth

How is depth measured?

The length of a side from bottom to top is height. The length of a side from left to right is breadth, or width. The length from front to back is depth, but depth can also be the length from top to bottom. The length from one corner to the opposite corner is just the length of the diagonal, no special words for that.

How is TVD calculated?

The formula are:

North = SUM ((MD2 - MD1) * Sin WD2 * Cos HAZ2)
East = SUM ((MD2 - MD1) * Sin WD2 * Sin HAZ2)
TVD = SUM ((MD2 - MD1) * Cos WD2)

What is datum pressure?

Well Testing] The depth to which pressures are corrected to adjust for differences in elevations at which pressure measurements are made in different wells or at different times. See: datum.