Oil and Gas Terms Beginning with “C”

C pump (centrifugal pump) in WCSB oil and gas surface operations is a kinetic-energy fluid transfer machine that uses a rotating impeller to impart velocity to the fluid, converting that kinetic energy into pressure… Read more →

Common depth point (CDP), also called common midpoint (CMP) in modern reflection seismic acquisition terminology, is the geometric point on the subsurface reflector that is equidistant from multiple source-receiver… Read more →

CEC is the standard abbreviation for cation exchange capacity, the quantitative measure of the total population of exchangeable positively charged ions held on clay mineral surfaces and organic matter in a rock sample… Read more →

CERCLA, the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (commonly known as Superfund), establishes the United States federal legal framework under which the Environmental Protection… Read more →

Cold Heavy Oil Production with Sand (CHOPS) is a primary recovery technique for extra-heavy oil in unconsolidated Cretaceous Mannville Group sands in the Western Canada Sedimentary Basin, in which sand grains are… Read more →

CI in oilfield operations is a widely used abbreviation with two primary meanings depending on context: corrosion inhibitor (CI), the chemical additive injected into production flowlines, wellbores, and gathering… Read more →

Carboxymethylcellulose (CMC) is an anionic water-soluble cellulose derivative manufactured by reacting natural cellulose with monochloroacetic acid and sodium hydroxide to form the sodium salt of carboxymethylcellulose,… Read more →

Carboxymethylhydroxyethylcellulose (CMHEC) is a mixed-substituent cellulose ether polymer manufactured by reacting natural cellulose with both chloroacetic acid (to attach anionic carboxymethyl groups, OCH2COO-, at… Read more →

Common midpoint (CMP) is the fundamental acquisition geometry principle underlying modern multichannel reflection seismic surveys, in which the midpoint on the surface between a seismic source and a receiver is shared… Read more →

Cement microstructure scanning (CMS) in oilfield cementing engineering is a family of laboratory and downhole analytical techniques applied to hardened Portland cement and specialty cement systems to characterize pore… Read more →

CO2 injection in the oil and gas industry is the deliberate subsurface delivery of carbon dioxide, either as a compressed gas, a dense-phase liquid, or a supercritical fluid (above the critical point of 31.1 degrees… Read more →

Chemical oxygen demand (COD) is a laboratory measurement that quantifies how much oxygen would be needed to chemically oxidize all the organic and inorganic oxidizable material in a water sample. It is expressed in… Read more →

COFCAW (combination of forward combustion and waterflooding) is a thermal enhanced oil recovery method for heavy oil and tar sand reservoirs in which an in-situ combustion front (created by injecting air or enriched air… Read more →

What Is CPMG? CPMG (Carr-Purcell-Meiboom-Gill) designates the radio-frequency pulse sequence used in nuclear magnetic resonance (NMR) logging and core analysis to measure hydrogen relaxation times in pore fluids,… Read more →

Cyclic steam stimulation (CSS), also called cyclic steam injection or the huff-and-puff process, is a thermal enhanced oil recovery method applied to heavy oil and bitumen reservoirs in which steam is injected into a… Read more →

CT (coiled tubing) in petroleum operations refers to a continuous, flexible steel or composite tube wound on a large reel (typically 1.5 to 3 meters in diameter) that is unspooled and injected into the wellbore through… Read more →

The Clean Water Act (CWA) is the principal United States federal statute governing the discharge of pollutants into navigable waters, and it sits at the center of nearly every produced-water, drilling-fluid, and… Read more →

Cable clamp in WCSB wireline and intervention operations is a mechanical or hydraulically actuated device that grips the wireline cable (slickline or electric line) at the surface to support the weight of the cable and… Read more →

Cantilever mast (also called a self-supporting mast or box mast in WCSB drilling rig engineering, and distinguished from a guyed mast by the absence of wire guy lines for lateral load resistance) is a drilling rig… Read more →

Catch samples (also called cuttings samples, drill cuttings samples, or wellsite geological samples) are the fragments of formation rock produced by the drill bit during rotary drilling operations that are carried to… Read more →

A chain tong is a manual pipe-gripping tool used throughout Western Canada Sedimentary Basin workover, completion, and well service operations to apply or resist torque on drill pipe, tubing, and casing connections… Read more →

The Chenevert method is a quantitative approach to shale wellbore stability analysis developed by Martin Chenevert and published in the Journal of Petroleum Technology in 1970, which treats shale instability in drilling… Read more →

A Christmas tree in petroleum production engineering is the assembly of valves, spools, fittings, and chokes installed at the top of the wellhead casing head to control the flow of oil, gas, or injection fluids into or… Read more →

What Is Compton Scattering? Compton scattering (also called incoherent scattering or Compton effect) is a gamma ray interaction mechanism in which an incident gamma photon collides with a loosely bound outer-shell… Read more →

Generally the first string of casing in a well, preventing surface formation collapse. Read more →

A sub that allows different sizes and types of drill string components to be joined together. Read more →

A device mounted near the drawworks drum to keep the driller from inadvertently raising the travelling block into the crown block. Read more →

A cut point (also called a cut temperature or distillation cut point) is the temperature at which the boiling fraction of a crude oil or refinery stream is divided between two products during atmospheric or vacuum… Read more →

Cable in WCSB wireline and well intervention operations is the metallic conductor wire or cable assembly that serves as the mechanical suspension medium and (for electric line cables) the electrical transmission path… Read more →

Cable head (also called rope socket for slickline operations, or top connector for electric line tool strings) in WCSB wireline and well intervention is the uppermost component of the downhole tool string, serving as… Read more →