- J -

Jack or Unit - An oil-pumping unit. The pumping jack's walking beam provides the up-and-down motion to the well's pump rods.

Jack-up rig - A floating platform with legs on each corner that can be lowered to the sea bottom to raise or jack up the platform above the water.

Jet fuel - See Kerosene.

Jetting - Injecting gas into a subsurface formation for the purpose of maintaining reservoir pressure.

Joint - A single section of drill pipe, casing, or tubing, usually about 30 feet long.

Joint Operating Agreement - A detailed written agreement between the working interest owners of a property which specifies the terms according to which that property will be developed.

Joint venture - A large-scale project in which two or more parties (usually oil companies) cooperate. One supplies funds and the other actually carries out the project. Each participant retains control over his share, including liability and the right to sell.

Junk basket - A magnet used to retrieve small tools lost in the well. A fishing instrument.

- K -

Kelly bushing - Part of the drilling rig, the Kelly is a long hollow steel bar that connects to the upper end of the drill string.

Kerogen - The hydrocarbon in oil shale. Scientists believe that kerogen was the precursor of petroleum and that petroleum development in shale was somehow prematurely arrested.

Kerosene - The petroleum fraction containing hydrocarbons that are slightly heavier than those found in gasoline and naphtha. Kerosene (also spelled kerosene) was the most important petroleum product because of its use for home and commercial lighting; in recent years demand has risen again as a result of kerosene's use in gas turbines and jet engines.

Keyseating - A condition in which the drill collar of another part of the drill string becomes wedged in a section of crooked hole.

Kick Occurs - when the pressure encountered in a formation exceeds the pressure exerted by the column of drilling mud circulating through the hole. If uncontrolled, a kick leads to a blowout.

Kill a well - To overcome downhole pressure by adding weighting elements to the drilling mud.

- L -

Lag time - The time it takes for cuttings to be carried (circulate) from the bottom of the borehole up to the surface by the mud system.

Landman - A self-employed individual or company employee who secures oil and gas leases, checks legal titles, and attempts to cure title defects so that drilling can begin.

Landowner royalty - The share of the gross production of the oil and gas on a property without deducting any of the cost of producing the oil or gas. The usual landowner's royalty is one-eighth of gross production.

Law of capture - A legal concept on which oil and gas law in some states is based: since petroleum is liquid, and hence mobile, it is not owned until it is produced.

Lead lines - The lines through which production from individual wells is run to tanks.

Lease (Oil and Gas) - A contract by which the owner of the mineral rights to a property conveys to another party, the exclusive right to explore for and develop minerals on the property, during a specified period of time.

Lease acquisition costs - Bonus payments.

Lease broker - An individual engaged in obtaining leases for speculation or resale.

Lease hound - Someone who goes out and aggressively acquires oil and gas leases from the landowner, and then turns around and sells or trades them to an oil company planning to drill a well in the area.

Lease offering (lease sale) - An area of land offered for lease - usually by the U.S. Department of Interior - for the exploration for and production of specific natural resources such as oil and gas. Such a lease conveys no title or occupancy rights apart from the right to search for and produce petroleum or other natural resources subject to the conditions stated in the lease.

Lease or Sublease - Any transaction in which the owner of operating rights in a property assigns all or a portion of these rights to any other party.

Lifting costs - The costs of producing oil from a well or lease; the operating expenses.

Lignite - A solid fuel of a grade higher than peat but lower than bituminous coal.

Limestone - Sedimentary rock largely consisting of calcite. On a world-wide scale, limestone reservoirs probably contain more oil and gas reserves than all other types of reservoir rock combined.

Limited partner - In a limited partnership, a partner whose liability is limited to the amount of his investment in the partnership (plus any assessments and his share of undistributed partnership earnings).

Limited partnership - A partnership in which the general partner manages the partnership's activities and is solely liable for them. The limited partners are liable only to the extent of their contributions.

LNG (liquefied natural gas) - Natural gas that has been converted to a liquid through cooling to -260 degrees Fahrenheit at atmospheric pressure.

Logs - Records made from data-gathering devices lowered into the wellbore. The devices transmit signals to the surface which are then recorded on film and used to make the record describing the formation's porosity, fluid saturation, and lithology. The filing of a log is required by the federal government if the drill site is on federal land.

Lost circulation - A serious condition that occurs when drilling mud pumped into the well does not return to the surface, but goes into the porous formation, crevices, or caverns instead.

LPG (liquefied petroleum gases) - Hydrocarbon fractions lighter than gasoline, such as ethane, propane and butane, kept in a liquid state through compression and/or refrigeration, commonly referred to as "bottled gas."