Process Engineering Term - A

ABANDONED WELL - A dry hole in which no producible oil or gas was present, or a well that has stopped producing. Abandoned wells must be plugged to prevent seepage of oil, gas, or water from one formation to another.

ABANDONED WELL - A well no longer in use; a dry hole that, in most states, must be properly plugged.

ACIDIZING A WELL- A technique for increasing the flow of oil from a well. Hydrochloric acid is pumped into the well under high pressure to reopen and enlarge the pores in the oil-bearing limestone formations.


ACID TREATMENT - A refining process in which unfinished petroleum products such as gasoline, kerosene, diesel fuels, and lubricating stocks are treated with sulfuric acid to improve color, odor, and other properties.

ACOUSTIC LOG - A generic term for a well log that displays any of several measurements of acoustic waves in rocks exposed in a borehole, e.g., compressional-wave transmit time over an interval (sonic log) or relative amplitude (cement bond log).

ACTIVE WELL - A well in mechanical condition for production or service use (i.e., in active production or service use).

AMINE - Organic base used in refining operations to absorb acidic gases (H2S, COS, CO2) occurring in process streams. Two common amines are monoethanolamine (MEA) and diethanolamine (DEA).

AMINE UNIT - A natural gas treatment unit for removing contaminants (H2S, COS, CO2) by the use of amines. Amine units are often skid-mounted so they can be moved to the site of new gas production. Gas containing H2S and other impurities must be cleaned up before it is acceptable to gas transmission pipelines.

ANTICLINE - An upfold or arch of stratified rock in which the beds or layers bend downward in opposite directions form the crest or axis of the fold.

API - The American Petroleum Institute is the oil industry's trade organization. API's research and engineering work provides a basis for establishing operating and safety standard issues; specifications for the manufacturing of oil field equipment; and furnishes statistical and other information to related agencies.

APPRAISAL DRILLING - Wells drilled in the vicinity of a discovery or wildcat well in order to evaluate the extent and the importance of the find.

AREA OF INTEREST - The area immediately surrounding a successful well in which the investors (in the good well) have an implied right to participate in any future wells drilled by the same operator.

ARTIFICIAL LIFT - Pumping an oil well with a rod, tubing, or bottom-hole centrifugal pump may be termed artificially lifting crude oil to the surface or doing so by mechanical means.

ASSIGNMENT - In oil and gas usage, assignment is a transfer of a property or an interest in an oil or gas property; most commonly, the transfer of an oil or gas lease. The assignor does the transferring and the assignee receives the interest of property.

ASSOCIATED GAS - Gas that occurs with oil, either as free gas or in solution. Gas occurring alone in a reservoir is unassociated gas. Gas combined with oil. Known also as gas cap gas and solution gas, it provides the drive mechanism needed to force oil to the surface of a well. Associated gas is normally present in an oil reservoir in the early stages of production.

ATTIC OIL - An unscientific, but descriptive term for the oil above the borehole in horizontal wells; oil in the top few feet of a productive interval which will gravitate or be pressured into the horizontal drain hole.

AUSTRALIAN OFFSET - A humorous reference to a well drilled miles away from proven production.