To sharpen, repair, or add accessories to items of equipment (such as drilling bits and tool joints).

A reservoir formation in which fluid or plastic masses of rock material originated at unknown depths and pierced or lifted the overlying sedimentary strata.

A well through which water (usually salt water) is returned to subsurface formations.

Natural gas which is in solution with crude oil in the reservoir.

A geologic structure resembling an inverted bowl; a short anticline that plunges on all sides.

A cutout section in a cone enabling positive slip movement without the aid of conventional slip return springs

Pertaining to the wellbore.

1.

The weight of a fluid (such as water) displaced by a freely floating or submerged body (such as an offshore drilling rig).

If the body floats, the displacement equals the weigh of the body.

2.

Teplacement of one fluid by another in the pore space of a reservoir.

For example, oil may be displaced by water.

3. the act of removing one fluid (usually liquid) from a wellbore and replacing it with another.

This is accomplished by pumping a spacer fluid that is benign to both the first and second fluid, followed by the new fluid, down the drillstring and out the bottom of the drillstring or bit. while the spacer and second fluid are pumped into the top of the wellbore, the first fluid is forced out of the annulus between the drillstring and the wellbore or casing.

In some cases, this general procedure may be reversed by pumping in the top of the annulus and taking fluid back from the drillstring.

Since this is the reverse of the normal circulation path, this is referred to as “reversing out” or “reverse circulation.”

A ring of wedges that supports a string of pipe or a threaded, tapered ring used for the same purpose.

The vertical distance between the bottom of a vessel floating in water and the waterline.

A particularly crooked place in a wellbore where the trajectory of the wellbore in three-dimensional space changes rapidly.

While a dogleg is sometimes created intentionally by directional drillers, the term also refers to a section of the hole that changes direction faster than anticipated or desired, usually with harmful side effects.

In surveying wellbore trajectories, a standard calculation of dogleg severity is made, usually expressed in two-dimensional degrees per 100 feet [degrees per 30 m] of wellbore length.

Generally, intentional doglegs are limited to 3-3.5 degrees/ 30m.

Higher doglegs may create problems , such as key seating or damage to the drillstring.

A well-servicing unit whose mast consists of two steel tubes.

Double-pole masts provide racking platforms for handling rods and tubing in stands and extend from 65 to 67 feet (20 meters) so that rods can be suspended as 50-foot (15 meter) doubles and tubing set back as 30-foot (9-meter) singles.

See pole mast.

A slip-type collar that is used to join plain-end pipe.

A mechanism used in packers to lock components together.

Material used on threads of pipe or tubing to lubricate and prevent leakage.