Oil and Gas Terms Beginning with “C” — Page 13

The weight loss of a corrosioncoupon after exposure to a corrosive environment, expressed as mils (thousandths of an inch) per year penetration. Corrosion rate is calculated assuming uniform corrosion over the entire… Read more →

A specially formulated material used for completion components in wells likely to present corrosion problems. Corrosion-resistant alloys can be formulated for a wide range of aggressive wellbore conditions. However,… Read more →

A chemical used in small quantities to improve the effectiveness of a primary solvent in a chemical process. Read more →

A portion of produced oil that the operator applies on an annual basis to recover defined costs specified by a production sharing contract. Read more →

A chemical added to a process to enhance the effectiveness of a surfactant. In the oil industry, cosurfactants are often used to increase the oil-solubilizing capacity of microemulsion surfactant systems. An example of… Read more →

Part of rod pumping unit. The counterbalance weight is installed on the end of the walking beam, opposite to the end over the well, and counterbalances the weight of the sucker rods and the fluid being pumped. Read more →

The lifting device on a snubbing unit used to pick up and lay down the tool string and running-string tubulars. Read more →

An electrical or mechanical device that joins parts of systems and can affect the interaction of, or energy transfer between, parts of systems. Electrical couplings promote the passage of certain signals but prevent the… Read more →

(noun) A small metal sample of known weight, dimensions, and metallurgy that is exposed to a corrosive environment within a pipeline, vessel, or wellbore for a specified period to measure the rate of corrosion by… Read more →

The process of splitting a large heavy hydrocarbon molecule into smaller, lighter components. The process involves very high temperature and pressure and can involve a chemical catalyst to improve the process efficiency. Read more →

A stable area of continental crust that has not undergone much plate tectonic or orogenic activity for a long period. A craton includes a crystalline basement of commonly Precambrian rock called a shield, and a platform… Read more →

The separation of phases of an emulsion with the lighter phase on top and denser phase on bottom. When oil muds are stagnant, the less dense oil phase rises and the denser aqueous phase settles. This behavior is not… Read more →

The highest point of a wave, mountain or geologic structure. Read more →

The change in oil-water or gas-oil contact profiles as a result of drawdown pressures during production. Cresting occurs in horizontal or highly deviated wells and is affected by the characteristics of the fluids… Read more →

The angle of incidence according to Snell's law at which a refracted wave travels along the interface between two media. It can be quantified mathematically as follows: Read more →

The minimum damping that will prevent or stop oscillation in the shortest amount of time, typically associated with oscillatory systems like geophones. Read more →

In sand control operations, the maximum production rate below which the production of solids along with the produced fluid is uniform. When the flow rate exceeds this threshold, the production of sand and fines… Read more →

The gas flow rate equivalent to the speed of sound in that fluid. Exceeding this limit during gas production accelerates corrosion in the pipelines. Read more →

A near-wellbore area where injected fluids such as acids can restore original permeability. Most of the reservoir pressure drop during production occurs in this near-wellbore part of the reservoir. Read more →

The time of maximum depth of burial of a hydrocarbon source rock. The critical moment is the time of highest probability of entrapment and preservation of hydrocarbons in a petroleum system-after traps form and… Read more →

The minimum rate required to achieve turbulent flow. Read more →

A reflection, typically at a large angle, that occurs when the angle of incidence and the angle of reflection of a wave are equal to the critical angle. Read more →

Antiquated term for a deviated wellbore, usually used to describe a well deviated accidentally during the drilling process. Read more →

Describing a waveform or a log that has been recorded by a set of dipole receivers oriented orthogonally (or 900 out of line) with a dipole transmitter. In soniclogging, cross-dipole flexural modes are used to determine… Read more →

Constant of proportionality relating the fraction of incident particles that undergo an interaction to the thickness and number of target atoms within a material, and the incident flux. It is a measure of the… Read more →

The comparison of different waveforms in digital form to quantify their similarity. A normalized crosscorrelation, or a correlation coefficient, equal to unity indicates a perfect match, whereas a poor match will yield… Read more →

A device for measuring fluid velocity in a production well. The device measures the transit time of a disturbance between two sensors separated by a fixed distance. The technology applies to multiphase flow, in which… Read more →

A condition that exists when two production zones with dissimilar pressure characteristics are allowed to communicate during production. Reservoir fluid from the high-pressure zone will flow preferentially to the… Read more →

A seismic line within a 3D survey perpendicular to the direction in which the data were acquired. Read more →

A compound, typically a metallic salt, mixed with a base-gel fluid, such as a guar-gel system, to create a viscous gel used in some stimulation or pipeline cleaning treatments. The crosslinker reacts with the… Read more →