Oil and Gas Terms Beginning with “D” — Page 7

The variation in the values of a one-dimensional data set. There are a number of readily recognized, possible distributions known to statistics, each with mathematical definitions. Statisticians may endeavor to find… Read more →

The daily variation in properties of the Earth, such as the temperature or the local geomagnetic field, or the daily change in sunlight. Such variations depend in part on latitude, proximity to the ocean, the effects of… Read more →

In Cartesian coordinates, divergence is the sum of the partial derivatives of each component of the vector field with respect to the corresponding spatial coordinate: Read more →

A technique used in injection treatments, such as matrixstimulation, to ensure a uniform distribution of treatment fluid across the treatment interval. Injected fluids tend to follow the path of least resistance,… Read more →

A device for measuring in-situ the velocity of fluid flow in a production or injection well in which the total fluid flow is diverted to pass over an impeller, or spinner. Various techniques have been used to achieve… Read more →

An agreement between the operator and net revenue interest (NRI) owner in which the parties specify the fractional type of interest attributed to the NRI owner by the operator after an examination of title. Read more →

A safety device used when running and retrieving tools or drill collars with a flush external surface that may easily pass through the rotary table slips. The dog collar is temporarily attached to the assembly between… Read more →

The steel-sided room adjacent to the rig floor, usually having an access door close to the driller's controls. This general-purpose shelter is a combination tool shed, office, communications center, coffee room,… Read more →

An abrupt turn, bend or change of direction in a survey line, a wellbore, or a piece of equipment. Dog-legs can be described in terms of their length and severity and quantified in degrees or degrees per unit of… Read more →

The steel-sided room adjacent to the rig floor, usually having an access door close to the driller's controls. This general-purpose shelter is a combination tool shed, office, communications center, coffee room,… Read more →

An abrupt turn, bend or change of direction in a survey line, a wellbore, or a piece of equipment. Dog-legs can be described in terms of their length and severity and quantified in degrees or degrees per unit of… Read more →

The name given to dolomitized limestone. Read more →

The geochemical process in supratidal sabkha areas where magnesium [Mg] ions from the evaporation of seawater replace calcium [Ca] ions in calcite, forming the mineraldolomite. The volume of dolomite is less than that… Read more →

A rock composed chiefly (> 90%) of dolomite. The rock is sometimes called dolomite, but dolostone is preferable to avoid ambiguity between the mineral and rock names. Replacement dolomite that forms soon after… Read more →

The set of values assigned to the independent variables of a function. Read more →

A structure made up of a number of superposed domains, usually of different size or wavelength. These are used in geostatistical work to describe statistical behaviors on small scales (such as porosity in thin sections)… Read more →

(noun) A geological feature in which a rock mass is divided into distinct structural domains, each with its own characteristic deformation style, fabric orientation, or strain pattern. In structural geology, domainal… Read more →

A type of anticline that is circular or elliptical rather than elongate. The upward migration of salt diapirs can form domes, called salt domes. Read more →

Slang term to describe a seismologist performing seismic field work. Read more →

To place lubricant on drillpipe, also known as "doping" the pipe. Read more →

A low-volume fluid pump with controllable discharge rate used to inject chemical additives to the mixing or pumping system. Dosing pumps frequently are used to inject fluids that may be difficult to mix efficiently in… Read more →

Located down the slope of a dipping plane or surface. In a dipping (not flat-lying) hydrocarbonreservoir that contains gas, oil and water, the gas is updip, the gas-oil contact is downdip from the gas, and the oil-water… Read more →

A pressure gauge, typically run on slickline, used to measure and record downhole pressure. Downhole gauges are commonly used in assessing the downhole pressure under various flowing conditions, the basis of pressure… Read more →

A receiver located in a wellbore, as opposed to a location on the Earth's surface. Read more →

A downhole device that isolates wellbore pressure and fluids in the event of an emergency or catastrophic failure of surface equipment. The control systems associated with safety valves are generally set in a fail-safe… Read more →

Mechanical or electronic devices for measuring various properties in the well such as pressure, fluid flow rate from each branch of a multilateral well, temperature, vibration, composition, fluid flow regime, and fluid… Read more →

A seismic source located in a wellbore rather than at the Earth's surface. Read more →

The termination of more steeply dipping overlying strata against a surface or underlying strata that have lower apparent dips; a term used to describe a particular geometry of reflections in seismic data in… Read more →

Pertaining to equipment, facilities or systems that are located in the production train after the surface choke, typically attached or close to the Christmas tree. Read more →

A pipeline that receives natural gas or oil from another pipeline at some specific connection point Read more →