Oil and Gas Terms Beginning with “C” — Page 4

What Is Casing Hardware? Casing hardware is the collective term for the functional downhole components — other than the casing joints and couplings themselves — that are assembled into the casing string before it is run… Read more →

What Is a Casing Joint? A casing joint is an individual length of steel tubular pipe that, when connected end-to-end with casing collars (couplings) or through integral connections, forms the continuous casing string… Read more →

What Is a Casing Patch? A casing patch is a downhole mechanical device — typically a steel sleeve or liner section with sealing elements — that is installed inside a damaged, corroded, or leaking section of production… Read more →

What Is a Casing Point? A casing point is the depth at which the drill string is pulled and a casing string is run, cemented, and pressure-tested before drilling is continued — the predetermined depth in the well design… Read more →

What Is Casing Pressure? Casing pressure is the fluid pressure measured at the surface in the annular space between the production tubing (or drill pipe) and the casing — the pressure in the annulus that reflects the… Read more →

What Is Casing Reciprocation? Casing reciprocation is the practice of moving the casing string up and down (reciprocating) while cement is being pumped into the annulus during primary cementing operations — a technique… Read more →

What Is a Casing Roller? A casing roller is a type of casing centralizer in which the standoff elements that hold the casing away from the borehole wall consist of rolling cylinders (rollers) mounted in a cage or frame… Read more →

What Is a Casing Scraper? A casing scraper is a downhole mechanical tool run on drill pipe, coiled tubing, or workover string to remove scale, cement, rust, paraffin, asphaltene, and other deposits from the interior… Read more →

What Is a Casing Shoe? A casing shoe (also called a guide shoe or float shoe) is the heavy, beveled steel fitting run on the bottom joint of a casing string that guides the casing through the wellbore during running… Read more →

What Is a Casing Shoe Test? A casing shoe test is a pressure integrity test performed immediately after drilling through the cement at the bottom of a newly set casing string (the casing shoe) and into the virgin… Read more →

What Is a Casing Spool? A casing spool is a flanged or threaded wellhead component installed on top of a casing head (or on top of a preceding casing spool in a stacked wellhead assembly) to provide a sealing housing… Read more →

What Is a Casing String? A casing string is an assembled series of steel pipe joints run into a wellbore and cemented in place to isolate formations, protect freshwater aquifers, provide structural support for wellhead… Read more →

What Is a Casing Swage? A casing swage is a solid or hollow tapered mandrel run on drill pipe or tubing to mechanically deform (swage) collapsed, buckled, or ovalized casing back toward its original circular… Read more →

What Is a Casing Test? A casing test is a pressure integrity test applied to a casing string — either immediately after cementing (formation integrity test or casing leak-off test) or as part of a well integrity… Read more →

What Is a Casing Thread? A casing thread is the helical groove machined into casing joint ends and couplings that enables the mechanical and pressure-sealing connection between adjacent casing tubulars — the male (pin)… Read more →

What Is a Casing Valve? Casing valve (also called an annular valve or casing spool valve ) is a manually or remotely actuated valve mounted on a side outlet of the casing spool or wellhead body to isolate, monitor,… Read more →

What Is a Casing Inspection Log? A casing inspection log is a wireline or production logging tool run inside the casing string to evaluate the mechanical integrity of the steel tubular — detecting corrosion, pitting,… Read more →

What Is a Casing Potential Profile? Casing potential profile (also called CPP or casing corrosion survey) is a wireline corrosion assessment technique that measures the electrochemical potential difference between the… Read more →

What Is a Casinghead? A casinghead (also written "casing head") is the lowermost structural component of a surface wellhead assembly — a heavy steel fitting welded or threaded directly to the top of the surface casing… Read more →

A relatively thin cable used with other equipment to move small rig and drillstring components and to provide tension on the tongs for tightening or loosening threaded connections. Read more →

Pertaining to a type of metamorphicrock with shearing and granulation of minerals caused by high mechanical stress during faulting or dynamic metamorphism, typically during episodes of plate tectonic activity. Read more →

Catagenesis is the stage of organic matter transformation in which buried kerogen undergoes thermally driven chemical breakdown to generate liquid hydrocarbons and natural gas. Occurring at temperatures between 50 and… Read more →

A clutched spool connected to the drawworks power system used to tension chains, cables and softline rope. Read more →

Cathodic protection (CP) is an electrochemical corrosion control technique in which the metal surface to be protected is made the cathode of an electrochemical cell, preventing oxidation reactions from dissolving the… Read more →

(noun) A positively charged ion formed when an atom loses one or more electrons. In drilling fluid chemistry, cations such as sodium (Na⁺), calcium (Ca²⁺), and potassium (K⁺) interact with clay minerals to influence… Read more →

Cation exchange capacity (CEC) is a measure of the total quantity of positively charged ions (cations) that a clay mineral or other charged solid can accommodate on its negatively charged surface, expressed in… Read more →

Quantity of positively charged ions (cations) that a claymineral (or similar material) can accommodate on its negative charged surface, expressed as milliequivalents per 100 grams. CEC of solids in drilling muds is… Read more →

A relatively thin cable used with other equipment to move small rig and drillstring components and to provide tension on the tongs for tightening or loosening threaded connections. Read more →

A long, rectangular platform about 3 ft [0.9 m] high, usually made of steel and located perpendicular to the vee-door at the bottom of the slide. This platform is used as a staging area for rig and drillstring tools,… Read more →

What Is a Caustic Extraction Test? Caustic extraction test (also called the lime content test or Pom determination) is a drilling fluid quality control procedure performed on oil-based and synthetic-based muds to… Read more →