Petroleum Abstracts uses a controlled vocabulary of index terms to index entries in the TULSA database. These terms are compiled in a set of two thesauri and their supplemental lists. New terms are added to the thesauri as needed. Together, the thesauri contain more than 78,000 terms with 200,000 relationships.
The PA indexing thesauri, developed over the course of decades and constantly evolving, have become an industry-standard taxonomy for oil and gas exploration and production (E&P).
PA's Exploration & Production Thesaurus is a collection of words and phrases descriptive of the concepts and equipment pertaining to petroleum exploration, development and production, exclusive of geographic areas and named geologic terms, which are included in PA's Geographic Thesaurus and its supplement.
The E&P Thesaurus comprises a controlled vocabulary for this subject area, in which the various concepts have been linked by means of generic or hierarchical relationships. These relationships may be truly generic or may be associations by use or even convenience.
All terms of like meaning are directed to one term for use as the index term for that particular concept. This selection usually follows popular usage and the patterns set by existing terms in the E&P Thesaurus. The chosen term is called a "valid" index term; other, like terms are called "invalid" and are not used for indexing.
E&P Thesaurus terms are interrelated on the concept-oriented (faceted) principle, and all descriptors are narrower terms of one of ten facet headings. These ten facets, which appear alphabetically, are as follows:
The supplement to PA's E&P Thesaurus consists of two parts:
The Geographic Thesaurus contains a listing of sedimentary basins, geographic features and geographic area terms and their relationships. Its format is patterned after the E&P Thesaurus in a hierarchical fashion.
The Geographic Thesaurus: Supplemental Terms contains the names of formations, groups, series, oil fields, anticlines, faults, counties, and similar terms that are not included in the Geographic Thesaurus proper. The E&P Thesaurus contains a set of terms for "Earth and Space Concepts" (e.g., DEPOSITIONAL ENVIRONMENT, FACIES, and BASIN) that are closely related to the terms in this Thesaurus.
All Geographic Thesaurus descriptors are part of a hierarchy that provides a compact listing of the terms in their structured form. WORLD is the top level of hierarchy for the Geographic Thesaurus. The terms at the next level down, which appear alphabetically, are as follows:
The Geographic Thesaurus contains names of countries; states and provinces; divisions of states (WEST TEXAS); geographic areas (LA PAZ AREA); geographic regions (ARAL REGION); continents; divisions of continents; oceans and seas; national parks; named geographic features; bays, gulfs and straits; coasts and beaches; ridges and mountains; valleys, canyons and plains; lakes and lagoons; peninsulas and islands; deserts; sedimentary basins, troughs and embayments; coal fields and basins; submarine fans and canyons; platforms, shelves, pendants, scarps, and escarpments. Also included are broad, basically structural features: uplifts, belts, arches, fault systems, fault belts, fracture zones, folded belts, and geosynclines, other broad features, and other similar terms.
The Geographic Thesaurus Supplement contains the names of formations, groups and series; US counties and parishes; oil and gas fields; named geologic features: anticlines and synclines, faults and folds, grabens and horsts, and other similar terms. PA's E&P Thesaurus contains the technical vocabulary used for geologic structures, rock types, earth age, and depositional and tectonic concepts.
GAS CHROMATOGRAPHY IN SITU COMBUSTION THRUST FAULT
ELECTRICAL USE ELECTRICITY
ELECTROMOTIVE FORCE USE ELECTRIC POTENTIAL EAST TEXAS AREA USE EAST TEXAS BASIN
GENERATOR (ELECTRICAL) USE ELECTRIC GENERATOR WELL DRILLING USE DRILLING (WELL)
MEXICO GULF FLORIDA STRAITS
The ultimate authority for the location of geographic terms is the published material from which they are derived. In general, geographic locations that are used in professional refereed publications are accepted as terms for this Thesaurus. The following reference publications are used for verification and definition of geographic names:
One or more of the following entries may be found in the thesaurus entry for a valid index term:
A maximum of 26 characters (letters and spaces) is allowed for each term. A few terms require more characters than 26, therefore some abbreviations are necessary. The single asterisk entry designates the entire spelling of such descriptors.
Scope Note entries (double asterisk) are used to restrict the scope of a term or to define its meaning, to instruct the indexer to use additional terms also, to tell when the term was first available for indexing, to show what terms were used previously to describe this area, and to indicate changes in hierarchical relationships. Numbers in parentheses show applicable year ranges, e.g., (1965-2001).
USE entries indicate the valid term used for indexing instead of the entry term
PLS (Plus) indicates the second term of a two-term synonym; used with the USE statement.
UF (Used For) indicates an invalid term that is directed to the preferred term under which it is listed.
WTH (With) indicates the second term of a two-term synonym; used with the UF statement.
NT (Narrow Term) designates a term which is a more specific subdivision of the term.
BT (Broad Term) designates one or more hierarchically related terms, of which the concept is a logical subdivision.
SA (See Also) usually designates terms that are related but have not been directly connected in a vertical hierarchical relationship. In some cases, the SAs give information about the location of the feature or the features encompassed by the feature.
