Oil and Gas Terms Beginning with “C” — Page 12

What Is a Control Line? Control line (also called a control umbilical or downhole control conduit) is a small-diameter hydraulic, electric, or fiber-optic line run from the surface wellhead or subsea control module down… Read more →

(noun) A directional survey method in which measurements of wellbore inclination and azimuth are taken at predetermined time intervals or depth stations during drilling operations to monitor the trajectory of the… Read more →

What Is Convection? Convection (also called convective heat transfer) is the transfer of thermal energy by the bulk movement of a fluid — gas, oil, water, or drilling mud — from a region of higher temperature to a… Read more →

What Is Conventional Mud? Conventional mud (also called conventional drilling fluid or water-based mud) is a drilling fluid formulated with water as the continuous phase, bentonite clay as the primary viscosifier and… Read more →

What Is a Conventional Reservoir? Conventional reservoir (also called a discrete accumulation or classic reservoir) is a petroleum accumulation in which buoyancy forces drive oil or gas upward through permeable carrier… Read more →

Convergence in petroleum geoscience refers to the systematic thinning and eventual termination of a sedimentary stratum between two reflection horizons on a seismic section, where the reflectors representing the top and… Read more →

What Is a Converted Wave? Converted wave (also called a PS wave or mode-converted wave) is a seismic wave that travels downward from the source as a compressional P-wave but converts to a shear S-wave upon reflection or… Read more →

What Is Conveyance? Conveyance (also called tool conveyance or downhole conveyance) is the method used to transport logging instruments, perforation guns, wellbore intervention tools, and completion equipment to a… Read more →

What Is Convolution? Convolution (also called the convolutional model of the seismic trace) is the mathematical operation that describes how a recorded seismic trace is produced as the convolution of the earth's… Read more →

A copolymer in petroleum chemistry is a polymer molecule formed by the polymerization of two or more chemically distinct monomer units arranged in a defined sequence along the polymer chain, distinguished from a… Read more →

What Is Copper Carbonate in Drilling? Copper carbonate (also called basic copper carbonate or malachite, chemical formula Cu 2 (OH) 2 CO 3 ) is a hydrogen sulfide (H 2 S) scavenger used in water-based drilling muds to… Read more →

A core is a cylindrical sample of subsurface rock extracted from a wellbore by replacing the drill bit with a coring assembly that cuts a continuous cylinder of rock rather than grinding it to cuttings — providing the… Read more →

What Is Core Analysis? Core analysis (also called core testing or petrophysical core evaluation) is the systematic laboratory measurement of physical, chemical, and petrophysical properties of rock samples extracted… Read more →

What Is a Core Gamma Log? Core gamma log (also called a core gamma ray scan or core GR scan) is a continuous gamma ray measurement made on a retrieved conventional core in the laboratory by passing the core through a… Read more →

What Is a Core Image? Core image (also called core photography or digital core documentation) is the acquisition of high-resolution digital photographs, X-ray computed tomography (CT) scans, and hyperspectral or SEM… Read more →

What Is a Core Plug? Core plug (also called a plug sample or core sample plug) is a small cylindrical specimen drilled from a conventional full-diameter core for quantitative reservoir characterization measurements.… Read more →

What Is Core Testing? Core testing (also called core analysis or core lab analysis) is the systematic laboratory measurement of physical, mechanical, and chemical properties of rock samples retrieved from a wellbore,… Read more →

What Is Coreflooding? Coreflooding is a laboratory test in which fluids are injected through a core plug or core composite at controlled temperature, pressure, and flow rate to measure reservoir rock properties under… Read more →

What Is a Coring Fluid? Coring fluid (also called coring mud or core-cut fluid) is a specially formulated drilling fluid used exclusively during the coring interval of a well to minimize contamination of the core sample… Read more →

What Is a Corkscrew Hole? Corkscrew hole (also called a spiraling wellbore or helical borehole) is a wellbore deviation anomaly in which the drill bit follows a helical or spiral path instead of a smooth planned… Read more →

What Is a Corrected Gamma Ray? Corrected gamma ray (also called the environmentally corrected gamma ray or borehole-corrected GR) is the gamma ray log reading after applying systematic adjustments for borehole diameter,… Read more →

What Is Correcting Pressure to a Datum? Correcting pressure to a datum (also called datum pressure correction or pressure normalization) is the reservoir engineering process of adjusting measured bottomhole pressures… Read more →

What Is Correlation? Correlation (also called well log correlation or stratigraphic correlation) is the process of identifying and matching equivalent rock units, formation tops, and stratigraphic markers between two or… Read more →

What Is a Correlation Log? Correlation log (also called a formation correlation log or stratigraphic correlation log) is any wireline log used specifically to identify and match equivalent stratigraphic markers,… Read more →

What Is a Correlogram? Correlogram (also called an experimental semivariogram or variogram cloud) is a graph that displays the spatial correlation structure of a reservoir property — such as porosity, permeability, or… Read more →

What Is Corrosion? Corrosion (also called metal deterioration or material degradation) is the chemical or electrochemical degradation of metal equipment — including tubing, casing, pipelines, pressure vessels, and… Read more →

What Is Corrosion Control? Corrosion control (also called corrosion management or corrosion mitigation) is the systematic program of chemical treatment, mechanical intervention, electrochemical protection, and material… Read more →

What Is a Corrosion Coupon? Corrosion coupon (also called a weight-loss coupon or mass-loss coupon) is a precisely weighed metal specimen — typically mild steel or the alloy of interest, approximately 1-3 inches long by… Read more →

What Is Corrosion Fatigue? Corrosion fatigue (also called fatigue corrosion or environmental fatigue) is the accelerated fatigue failure of metal components under cyclic mechanical loading in a corrosive environment,… Read more →

What Is a Corrosion Inhibitor in Oil and Gas? A corrosion inhibitor is a chemical compound injected into oil and gas production systems to reduce the rate of metal deterioration caused by corrosive fluids — primarily… Read more →