A vessel, tank or tower in which a specific chemical reaction takes place.

Recoverable Reserves

That proportion of the oil and/or gas in a reservoir that can be removed using currently available techniques.


The process undertaken to regain material for human use. To reuse; to make ready for reuse.


A plant used to separate the various components present in crude oil and convert them into usable fuel products or feedstock for other processes.

Refining Margins

The difference in value between the products produced by a refinery and the value of the crude oil used to produce them. Refining margins will thus vary from refinery to refinery and depend on the price and characteristics of the crude used.

Reformulated Gasoline

Reformulated gasoline is a cleaner-burning gasoline that reduces smog and other air pollution. Federal law mandates the sale of reformulated gasoline in nine metropolitan areas with the worst ozone smog: Baltimore, Chicago, Hartford, Houston, Los Angeles, Milwaukee, New York, Philadelphia, and San Diego. Some other cities voluntarily require reformulated gasoline. About 20 to 25 percent of the gasoline sold in the United States is reformulated. It has the same effect on the environment as taking seven million cars off the road, according to EPA.


An economically recoverable quantity of crude oil and gas that has not yet been produced from reservoirs.


A porous, permeable sedimentary rock formation containing oil and/or natural gas enclosed or surrounded by layers of less permeable or impervious rock.

Reservoir Characterization

The continuing process of integrating and interpreting geological, geophysical, petrophysical, fluid and performance data to form a unified, consistent description of a reservoir.

Residual Fuel Oil

Very heavy fuel oils produced from the residue from the fractional distillation process rather than from the distilled fractions.

Residue Gas

The gas that remains after natural gas is processed and the liquids removed.


A solid or semi-solid mixture of organic substances of complex composition having no definite melting point, as in plastic resins made from hydrocarbon feedstocks.


Reduced Volatility Alkylation Process. An environmental innovation that cuts by 60 to 90 percent the airborne hydrogen fluoride (HF) emissions in the event of an accidental release. Phillips and Mobil jointly developed the process in 1994.

Reworking a Well

Restoring a well’s productivity by cleaning out accumulations of sand, silt or other substances that clog the production tubing.


A structure that contains all the necessary equipment for drilling.


The strip of land, usually 50 feet wide, that is the route of a pipeline and for which the company pays for the legal right of passage.


A share of the revenue from the sale of oil, gas or other natural resources paid to a landowner of grantor of a lease or license.

Royalty Oil

The landowner’s share of net oil production, taken in the form of crude oil rather than in cash.


Phillips' brand name for high-performance resins used in applications requiring resistance to heat or abrasive chemicals, such as automotive components.