A traveling block is the freely moving section of a block and tackle that contains a set of pulleys or sheaves through which the drill line is threaded or reeved and is opposite the crown block.
A crown block is the stationary section of a block and tackle that contains a set of pulleys or sheaves through which the drill line is threaded or reeved and is opposite and above the traveling block.
A drill string on a drilling rig is a column, or string, of drill pipe that transmits drilling fluid and torque to the drill bit. The term is loosely applied to the assembled collection of the drill pipe, drill collars, tools and drill bit. The drill string is hollow so that drilling fluid can be pumped down through it and circulated back up the annulus.
On larger diameter lines, traveling block loads of over a million pounds are possible.
To make a connection is to add another segment of drill pipe onto the top the drill string. A segment is added by pulling the kelly above the rotary table, stopping the mud pump, hanging off the drill string in the rotary table, unscrewing the kelly from the drill pipe below, swinging the kelly over to permit connecting it to the top of the new segment (which had been placed in the mousehole), and then screwing this assembly into the top of the existing drill string. Mud circulation is resumed, and the drill string is lowered into the hole until the bit takes weight at the bottom of the hole. Drilling then resumes.
Drill pipe, is hollow, thin-walled, steel or aluminium alloy piping that is used on drilling rigs. It is hollow to allow drilling fluid to be pumped down the hole through the bit and back up the annulus. It comes in a variety of sizes, strengths, and wall thicknesses, but is typically 27 to 32 feet in length. Longer lengths, up to 45 feet, exist.
A kelly drive refers to a type of well drilling device on an oil or gas drilling rig that employs a section of pipe with a polygonal or splined outer surface, which passes through the matching polygonal or splined kelly (mating) bushing and rotary table. This bushing is rotated via the rotary table and thus the pipe and the attached drill string turn while the polygonal pipe is free to slide vertically in the bushing as the bit digs the well deeper. 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.
The mousehole is the storage area on a drilling rig where the next joint of drilling pipe is held until needed. This hole is in the floor of the rig, bored into the earth for a short way, and usually lined with a metal casing known as a scabbard.
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Directional drilling is the practice of drilling non-vertical wells. It can be broken down into four main groups: oilfield directional drilling, utility installation directional drilling, directional boring, and surface in seam (SIS), which horizontally intersects a vertical well target to extract coal bed methane.
A drilling rig is a machine that creates holes in the earth's subsurface. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person and such are called augers. Drilling rigs can sample subsurface mineral deposits, test rock, soil and groundwater physical properties, and also can be used to install sub-surface fabrications, such as underground utilities, instrumentation, tunnels or wells. Drilling rigs can be mobile equipment mounted on trucks, tracks or trailers, or more permanent land or marine-based structures. The term "rig" therefore generally refers to the complex equipment that is used to penetrate the surface of the Earth's crust.
In geotechnical engineering, drilling fluid, also called drilling mud, is used to aid the drilling of boreholes into the earth. Often used while drilling oil and natural gas wells and on exploration drilling rigs, drilling fluids are also used for much simpler boreholes, such as water wells.
In drilling technology, casing string is a long section of connected oilfield pipe that is lowered into a wellbore and cemented. The purpose of the casing pipe is as follows:
Directional Boring, often undifferentiated from Horizontal Directional Drilling (HDD), is a minimal impact trenchless method of installing underground pipe, conduit, or cables in a relatively shallow arc or radius along a prescribed underground bore path by using a surface-launched drilling rig. With respect to the pipeline/utility industry, the term "Directional Boring" or "Bore" is generally reserved for mini/small sized drilling rigs, small diameter bores, and crossing lengths in terms of hundreds of feet. Generally, the term Horizontal Directional Drilling (HDD) is intended to describe large/maxi sized drilling rigs, large diameter bores, and crossing lengths in terms of thousand of feet. Although directional boring and HDD are similar in some respects to directional drilling associated with the oil industry, an equal comparison cannot be drawn between the procedures as they serve two entirely different functions. Directional Boring/HDD offers significant advantages over traditional cut and cover pipeline/utility installations and are routinely used when trenching or excavating is not practical. Directional Boring/HDD can be utilized with various pipe materials such as PVC, polyethylene, polypropylene, ductile iron, and steel as long as the pipe is sized appropriately to withstand installation stresses imparted during pullback.
Underbalanced drilling, or UBD, is a procedure used to drill oil and gas wells where the pressure in the wellbore is kept lower than the static pressure then the formation being drilled. As the well is being drilled, formation fluid flows into the wellbore and up to the surface. This is the opposite of the usual situation, where the wellbore is kept at a pressure above the formation to prevent formation fluid entering the well. In such a conventional "overbalanced" well, the invasion of fluid is considered a kick, and if the well is not shut-in it can lead to a blowout, a dangerous situation. In underbalanced drilling, however, there is a "rotating head" at the surface - essentially a seal that diverts produced fluids to a separator while allowing the drill string to continue rotating.
The original depth recorded while drilling an oil or gas well is known as the driller's depth.
In the oil and gas industries, coiled tubing refers to a very long metal pipe, normally 1 to 3.25 in in diameter which is supplied spooled on a large reel. It is used for interventions in oil and gas wells and sometimes as production tubing in depleted gas wells. Coiled tubing is often used to carry out operations similar to wirelining. The main benefits over wireline are the ability to pump chemicals through the coil and the ability to push it into the hole rather than relying on gravity. Pumping can be fairly self-contained, almost a closed system, since the tube is continuous instead of jointed pipe. For offshore operations, the 'footprint' for a coiled tubing operation is generally larger than a wireline spread, which can limit the number of installations where coiled tubing can be performed and make the operation more costly. A coiled tubing operation is normally performed through the drilling derrick on the oil platform, which is used to support the surface equipment, although on platforms with no drilling facilities a self-supporting tower can be used instead. For coiled tubing operations on sub-sea wells a mobile offshore drilling unit (MODU) e.g. semi-submersible, drillship etc. has to be utilized to support all the surface equipment and personnel, whereas wireline can be carried out from a smaller and cheaper intervention vessel. Onshore, they can be run using smaller service rigs, and for light operations a mobile self-contained coiled tubing rig can be used.
See snubber for a device used to suppress ("snub") voltage transients in electrical systems
A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The well water is drawn by a pump, or using containers, such as buckets, that are raised mechanically or by hand. Wells were first constructed at least eight thousand years ago and historically vary in construction from a simple scoop in the sediment of a dry watercourse to the qanats of Iran, and the stepwells and sakiehs of India. Placing a lining in the well shaft helps create stability, and linings of wood or wickerwork date back at least as far as the Iron Age.
Oilfield terminology refers to the jargon used by those working in fields within and related to the upstream segment of the petroleum industry. It includes words and phrases describing professions, equipment, and procedures specific to the industry. It may also include slang terms used by oilfield workers to describe the same.
A rotary table is a mechanical device on a drilling rig that provides clockwise 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).
Tripping pipe is the physical act of pulling the drill string out of the wellbore and then running it back in. This is done by physically breaking out or disconnecting every other 2 or 3 joints of drill pipe at a time and racking them vertically in the derrick. When feasible the driller will start each successive trip on a different "break" so that after several trips fresh pipe dope will have been applied to every segment of the drill string.
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. It is located at the swivel's place below the traveling block and moves vertically up and down the derrick.
A draw-works is the primary hoisting machinery component of a rotary drilling rig. Its main function is to provide a means of raising and lowering the traveling block. The wire-rope drill line winds on the drawworks drum and over the crown block to the traveling block, allowing the drill string to be moved up and down as the drum turns. The segment of drill line from the drawworks to the crown block is called the "fast line". The drill line then enters the first sheave of the crown block and makes typically 6 to 12 passes between the crown block and traveling block pulleys for mechanical advantage. The line then exits the last sheave on the crown block and is fastened to a derrick leg on the other side of the rig floor. This section of drill line is called the "dead line."
Pipe recovery is a specific wireline operation used in the oil and gas industry, when the drill string becomes stuck downhole. Stuck pipe prevents the drill rig from continuing operations. This results in costly downtime, ranging anywhere from $10,000-1,000,000 per day of downtime, therefore it is critical to resolve the problem as quickly as possible. Pipe recovery is the process by which the location of the stuck pipe is identified, and the free pipe is separated from the stuck pipe. This allows fishing tools to subsequently be run down hole to latch onto and remove the stuck pipe.
