Oil and Gas Terms Beginning with “C” — Page 5

What Is Caustic Potash? Caustic potash (also called potassium hydroxide or KOH ) is a strong inorganic alkali used in oil and gas drilling fluids to raise and control pH, neutralize acid gases, precipitate calcium and… Read more →

What Is Caustic Soda? Caustic soda is sodium hydroxide (NaOH), a strong alkali used in water-based drilling fluids to raise and maintain pH, control clay hydration, neutralize acid gases such as hydrogen sulfide and… Read more →

What Is the Cave Effect? Cave effect (also called borehole enlargement effect or washout effect) is the systematic degradation of petrophysical log measurements caused by borehole diameter enlargement beyond the nominal… Read more →

Pieces of rock that came from the wellbore but that were not removed directly by the action of the drill bit. Cavings can be splinters, shards, chunks and various shapes of rock, usually spalling from shale sections… Read more →

What Is Cavitation? Cavitation is a hydraulic phenomenon in which vapour bubbles form in a liquid when the local pressure drops below the liquid's vapour pressure — and then collapse violently when those bubbles are… Read more →

A dug-out area, possibly lined with wood, cement or very large diameter (6 ft [1.8 m]) thin-wall pipe, located below the rig. The cellar serves as a cavity in which the casing spool and casinghead reside. The depth of… Read more →

What Is Oil Well Cement? Oil well cement is a specialized Portland-based hydraulic cement pumped into the annular space between steel casing and the surrounding formation to provide zonal isolation, deliver mechanical… Read more →

What Is a Cement Accelerator? A cement accelerator is a chemical additive blended into oilfield cement slurry to shorten the thickening time (the time before the slurry becomes too thick to pump) and reduce the… Read more →

What Is a Cement Additive? A cement additive is any chemical or material blended into an oilfield cement slurry to modify its properties — including setting time, density, fluid loss, rheology, compressive strength… Read more →

What Is a Cement Bond Log? A cement bond log (CBL) is a wireline acoustic logging tool that evaluates the quality of the cement bond between the casing and the formation — measuring whether the cement in the annular… Read more →

What Is a Cement Dispersant? A cement dispersant (also called a cement thinner or cement plasticiser) is a chemical additive blended into Portland cement slurries to reduce viscosity and yield point by adsorbing onto… Read more →

What Is a Cement Extender? A cement extender is any additive blended with API Class G or Class H Portland cement that increases slurry yield—the volume of slurry produced per sack of cement—by replacing a portion of… Read more →

What Is a Cement Head? A cement head (also called a plug container or plug launching head) is a specialized surface cementing tool that threads or flanges onto the top joint of the casing string to serve as the… Read more →

What Is a Cement Plug? A cement plug is a column of hardened cement placed at a specific depth inside a wellbore to permanently or temporarily seal the well, isolate a zone, or provide a mechanical barrier during… Read more →

What Is a Cement Retainer? A cement retainer is a downhole packer-type tool run on drill pipe or tubing and set at a specified depth in the casing to create a pressure-tight mechanical seal that allows cement slurry to… Read more →

What Is a Cement Retarder? A cement retarder is a chemical additive blended into oil well cement slurries to extend the thickening time — the period during which the slurry remains pumpable — so that cementing… Read more →

What Is a Cement Squeeze? A cement squeeze is a remedial cementing operation in which cement slurry is pumped under pressure through perforations, holes, or slots in the casing into the annular space between the casing… Read more →

What Is Cementation? Cementation is the diagenetic process by which minerals precipitate from pore fluids and accumulate in the pore spaces and on grain surfaces of a sedimentary rock, progressively reducing porosity… Read more →

What Is the Cementation Exponent? The cementation exponent (symbol m ) is a dimensionless parameter in Archie's law that describes the geometry of the pore network in a reservoir rock — specifically how tortuously the… Read more →

The colloquial term for the crew member in charge of a specialized cementing crew and trucks. Read more →

What Is Cementing in Oil and Gas? Cementing is the well construction operation that pumps a precisely engineered cement slurry down the inside of a casing string and back up the annular space between the casing and the… Read more →

What Is a Cementing Plug? A cementing plug is a rubber wiper plug pumped through the inside of a casing string during a cement job to physically separate the cement slurry from the drilling fluid ahead of it and the… Read more →

A unit of measurement for viscosity equivalent to one-hundredth of a poise and symbolized by cp. Viscosity is the ratio of shear stress to shear rate, giving the traditional unit of dyne-sec/cm2 for Poise. In metric… Read more →

What Is a Centralizer? A centralizer is a mechanical device clamped or threaded onto the outside of casing or a liner string to hold the pipe approximately concentric within the wellbore , ensuring that cement slurry… Read more →

What Is a Centrifugal Pump? A centrifugal pump is a rotodynamic pump that uses a rotating impeller to impart kinetic energy to a fluid — converting mechanical energy from a motor into velocity energy in the fluid, then… Read more →

What Is a Centrifuge in Drilling? A centrifuge in drilling operations is a mechanical solids-control device that uses high rotational speed to generate centrifugal forces — typically 500 to 3,000 times the force of… Read more →

What Is Cesium Acetate? Cesium acetate (CsCH3COO, also written as CsOAc) is a solids-free clear brine completion and workover fluid based on the cesium salt of acetic acid. When dissolved in water at maximum… Read more →

What Is Cesium Formate? Cesium formate (also called CsCHO2 or cesium methanoate) is the highest-density solids-free clear brine used as a completion, packer, and drill-in fluid for high-pressure wells. Prepared by… Read more →

What Are Chain Tongs? Chain tongs (also called chain pipe wrenches ) are a manual pipe gripping tool consisting of a rigid steel handle fitted with a loop of articulated roller chain that wraps around the outside… Read more →

A porousmarinelimestone composed of fine-grained remains of microorganisms with calcite shells, coccolithophores, such as the White Cliffs of Dover (UK). The Austin Chalk of the US Gulf coast is a prolific, fractured… Read more →