Line cleaning instrument. A small plug which is run through a line.

A hole from 30 to 35 feet deep, with casing that projects above the derrick floor, into which the kelly is placed when hoisting operations are in progress.

An operation whereby a completion in one zone is abandoned in order to attempt a completion in a different zone within the existing wellbore. (See WORKOVER).

Process of balancing records. An example is when an individual balances a checking account record with the monthly bank statement. Once the records accurately agree, the checking account has been reconciled.

The gas produced at the tail gate of a gas processing plant after all natural gas liquids and natural gas liquid products have been removed.

A portion of an economic interest that will be returned to its former owner after a predetermined amount of production or income has been produced.

The interest kept by the grantor when selling or assigning interest to another.

The land owner's (lessor's) share of oil or gas production (typically 1/8, 1/6, or 1/4) free of cost, but subject to severance taxes unless the lessor is a government.

Royalty Cutback is for Financial Reporting purposes only. If there is no Royalty Owners on the deck then there will be no Royalty Cutback.

A record of the quantity of oil removed out of a stock tank into a pipeline or tank truck. A run ticket will generally have opening and closing volumes, observed gravity and temperature, BS&W, and date and time of delivery. It is usually made in triplicate and filled out by the gauger employed by the purchaser and sometimes witnessed by the pumper or employee of the company operating the well.

Now refers to water flooding. Used to refer to any process of injecting water, gas, etc., into a formation to build up pressure in order to produce additional oil otherwise unobtainable by primary recovery.

Reserves recoverable by secondary recovery.

An exploration method of sending energy waves or sound waves into the earth and recording the wave reflections to indicate the type, size, shape, and depth of subsurface rock formations. 2D seismic gives two dimensional information. 3D seismic provides three dimensional pictures. 4D seismic provides 3D pictures over time, used to indicate fluid movement in producing reservoirs.

A device for detecting vibrations in the earth. It is used in prospecting for probable oil-bearing structures.

A cylindrical or spherical device located at the well site to separate commingled oil and gas through gravity and centrifugal force. The oil will drop out and the gas will rise and escape through separate outlets.

Shooting seismic. Exploding nitroglycerin or other high explosives in a hole to shatter the rock and increase the flow of oil.

A well which is capable of producing oil or gas but which is not on production.

A small diameter well, generally drilled to achieve less expensive exploration or limited development. A slim hole development well cannot generally be re-completed and cannot be as easily repaired as a normal diameter well. Should a producing slim hole well have behind-pipe reserves, a second well normally must be drilled to produce such reserves

Disclosure called the standardized measure of discounted future net cash flows relating to proved oil and gas reserves.

Oil or gas with a high sulfur content.

The regulation of the number of wells which can be drilled on a given area of land. Depending on the depth of the reservoir, this may be one well on 5 to 640 acres. Typical spacing is 40 acres for oil wells and 640 acres for gas wells. However, spacing for tight sands gas production may be 20 acres.

One gas well being connected to more than one pipeline. This is caused by two or more working interest owners selling to different pipelines.

To commence actual drilling operations.

A well drilled outside well locations offsetting a producing well but within the possible or probable extent of the reservoir. (See OUTPOST WELL).

A mechanical process (such as fracing) or a chemical process (such as acidizing) to change the characteristics of the reservoir portion near a well to increase well production. (See ACIDIZE, FRACTURING, and WORKOVER).

A well drilled to obtain information about geologic conditions.

To pull both the rods and tubing from a well simultaneously.

Oil or gas containing a relatively small amount of sulfur.

Abbreviation for total depth, the bottom of the well.

One which has not been drilled or equipped for production.

A method of computing depreciation or depletion provisions based on quantities produced in relation to reserves.

An agreement under which two or more persons owning operating mineral properties agree to have the properties operated on a unified basis and further agree to share in production from all the unitized properties on a stipulated percentage or fractional basis regardless of which property the oil or gas is produced from . All owners of economic interests in the properties should be involved in the agreement.

A device used to control the rate of flow in a line, to open or shut off a line completely, or to serve as an automatic or semiautomatic safety device.

The secondary recovery method in which water is forced down injection wells laid out in various patterns around the producing wells. The water injected displaces the oil and forces it to the producing wells.

The equipment used to maintain surface control of a well.

Gas that contains a large quantity of liquid.

A stratigraphic interval containing one or more reservoirs.