Glossary#

API Well Number#

An API (American Petroleum Institute) well number is a “unique, permanent, numeric identifier” assigned to each well drilled for oil and gas in the United States. An API well number can have up to 14 digits divided by dashes as follows: 42-501-20130-03-00.

The “42” means that this well is located in “State Code” 42 which is Texas. The “501” means that this well is located in “County Code” 501 which is Yoakum County. The “20130” is a “Unique Well Identifier” within the county. The “03” is the “Directional Sidetrack Code” for wells that have been sidetracked. The “00” is the “Event Sequence Code” to indicate how many operations have taken place.

Base Line#

In the United States Public Land Survey System, a baseline is the principal east-west line (i.e., a parallel) upon which all rectangular surveys in a defined area are based. A baseline is the line that divides a survey township between north and south.

BBL#

The abbreviation BBL refers to a barrel of crude oil. In the oil industry, an oil barrel is 42 US gallons.

Drilling Method#

Oil and gas exploration makes use of several types of drilling methods and platforms based on the type of formations, geographic location, soil type and the like.

The five most common drilling methods used in extracting oil and gas from beneath the earth are:

  • Percussion or Cable Drilling

  • Rotary Drilling

  • Dual-Wall Reverse-Circulation Drilling

  • Electro-Drilling

  • Directional Drilling

Horizontal Well#

Horizontal wells are wells drilled at an angle (usually with an inclination greater than 85°). Horizontal wells enhance reservoir performance by allowing a longer wellbore section within the reservoir.

Forecasting#

Forecasting is a valuable tool used to predict fluctuations in gas production. These fluctuations can lead to ‘imbalances’ which may hurt shareholder interests which rely on receiving accurate information pertaining to gas prices. In such a scenario, forecasting becomes an essential source of information giving the user greater leverage over the market.

Forecasting is often done by using models that take into account the geology of the gas field, the location of the well, historical data, and other factors.

The Hyperion API production forecasts use:

  • All available field data or suitable analogues of input parameters

  • An understanding of limitations of the production system

  • Data on system availability and activity scheduling

  • A consistent set of assumptions and variables accounting for uncertainty

  • Records of actual performance against past forecasts and future changes that may occur

Formation#

A formation is a homogenous body of rock that differentiates it from neighboring sedimentary rocks and that can be mapped in geological maps.

GOR#

Gas-to-oil ratio (GOR) is a measurement used in the oil and gas industry that expresses the volume of gas produced per volume of oil in an oil well or reservoir. It represents the relationship between the amount of gas and the amount of oil that is produced.

If the GOR is equal to or less than 6,000 cf/b, it is as an oil well. If the GOR is greater than 6,000 cf/b, it is classified as a natural gas well. GOR tends to increase over the lifetime of an oil field as reservoir pressure declines.

In summary, gas-to-oil ratio is a key parameter used to evaluate oil and gas wells and fields. It measures the relative amounts of gas and oil produced, with higher ratios indicating more gas relative to oil. GOR provides insight into reservoir characteristics and changes over time.

To learn more about gas-to-oil ratio, please visit the EIA website.

Measured Depth#

Measured depth is the total length of the wellbore measured along the actual well path.

Principal Meridian#

In the United States Public Land Survey System, a principal meridian is the principal north-south line used for survey control in a large region, and which divides townships between east and west.

Range#

A range measures east or west from the principal meridian which is a designated meridian. Ranges are usually six miles in size.

Section#

Sections ae subdivisions of townships. Each township usually measures six miles by six miles, therefore each township contains 36 square miles, each one forming a section.

Spudding#

Spudding is the process of beginning to drill a well in the oil and gas industry. A larger drill bit is initially used to clear a surface hole, which is then lined with casing and cement to protect groundwater. After the surface hole is completed, the main drill bit (which performs the task of drilling to the total depth) is inserted. This process can also be referred to as “spudding in.”

Total Vertical Depth#

Total (or true) vertical depth (TVD) is measured as a straight perpendicular line from the surface down to a certain target (usually the bottom of the borehole).

Township#

A township measures the distance north or south from the base line which is a designated parallel. A township usually measures six miles in size.

Well Pad#

The well pad refers to the location where a drill rig is built, and from which the drill hole originates.

Well Bore#

A well bore is a hole with a narrow shaft that forms the actual oil or gas well. It may be encased by materials such as steel and cement, or it may be uncased. It also includes the open hole and uncased portions of the well.

WGS 84/EPSG:4326 Coordinate System#

WGS 84 (World Geodetic System 1984) is a widely accepted standard for representing geographic coordinates on Earth. It is used in GPS systems, GIS applications, and various geospatial data formats. This API uses the WGS 84/EPSG:4326 coordinate system for all latitudinal and longitudinal data.

The WGS 84/EPSG:4326 coordinate system uses the following properties: - Angular unit: degrees - Datum: WGS 84 - Prime meridian: Greenwich - Axis order: latitude, longitude