Drill line
Encyclopedia
In a drilling rig
Drilling rig (petroleum)
This article lists the main components of a petroleum onshore drilling rig.Offshore drilling rigs have similar elements, but are configured with a number of different drilling systems to suit drilling in the marine environment....
, the drill line is a multi-thread, twisted wire rope that is threaded or reeved through the traveling block
Traveling block
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 and is opposite the crown block ....
and crown block
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 and is opposite and above the traveling block....
to facilitate the lowering and lifting of the drill string
Drill string
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 as the assembled collection of the drill pipe, drill collars, tools and drill bit...
into and out of the wellbore
Wellbore
A wellbore is any hole drilled for the purpose of exploration or extraction of natural resources such as water, gas or oil where a well may be produced and a resource is extracted for a protracted period of time....
.
On larger diameter lines, tension strengths over a million pounds are possible.
To make a connection is to add another segment of drill pipe
Drill pipe
Drill pipe, is hollow, thick-walled, steel piping that is used on drilling rigs to facilitate the drilling of a wellbore and comes in a variety of sizes, strengths, and weights but are typically 30 to 33 feet in length...
onto the top the drill string
Drill string
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 as the assembled collection of the drill pipe, drill collars, tools and drill bit...
. A segment is added by pulling the kelly
Kelly drive
A kelly drive refers to a type of well drilling device on an oil drilling rig that employs a section of pipe with a polygonal or splined outer surface, which passes through the matching polygonal or splined kelly bushing and rotary table...
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
Mousehole (drilling)
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 ways, and usually lined with a metal casing known as a scabbard....
), 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.