Oil and Gas Terms Beginning with “C” — Page 9

A coiled tubing unit (CTU) is the complete surface equipment package used to deploy and operate a coiled tubing string in oil and gas well intervention, completion, stimulation, and drilling operations, consisting of… Read more →

Petroleum coke (petcoke) is the solid carbonaceous residue produced as a byproduct of petroleum refining and bitumen upgrading operations when residual vacuum tower bottoms and atmospheric residue are thermally cracked… Read more →

Cokriging is a multivariate geostatistical interpolation technique that estimates the value of a primary variable at unsampled locations by simultaneously exploiting the spatial auto-covariance of the primary variable… Read more →

Cold heavy oil production with sand (CHOPS) is a non-thermal primary recovery technique applied to shallow unconsolidated heavy oil reservoirs in which reservoir sand is intentionally co-produced alongside heavy crude… Read more →

Cold production is the collective term for nonthermal primary recovery methods applied to heavy oil reservoirs, encompassing any technique that recovers oil without injecting steam, solvent, or other heat-carrying… Read more →

Collapse pressure is the external differential pressure at which a tubular — casing string, production tubing, or coiled tubing — catastrophically deforms inward as the pipe wall buckles under net compressive hoop… Read more →

A collar in oilfield tubular goods is the externally threaded coupling that connects two adjacent joints of casing or tubing by engaging the pin end (male thread) of each joint into the box end (female thread) of the… Read more →

A collar locator (also abbreviated CCL for casing collar locator) is a downhole logging tool or sub that detects the electromagnetic anomaly produced by each casing or tubing collar — the coupling connecting adjacent… Read more →

A collar lock (also called a casing collar locator lock, CCL lock, or tubing stop) is a downhole mechanical anchoring device used in wireline and coiled tubing operations to secure a tool assembly at a specific casing… Read more →

A collar log (also called a CCL log or casing collar log) is the wireline log record produced by running a casing collar locator through a cased wellbore, displaying the electromagnetic voltage spike at each casing… Read more →

A collector (also called an electrical slip ring, reel collector, or rotary electrical coupling) is the electromechanical device mounted on the axle of a coiled tubing reel that maintains continuous electrical… Read more →

Collision is the tectonic process in which two lithospheric plates converge and physically impinge upon each other, transferring compressional stress that deforms, thickens, and elevates the crust to form mountain… Read more →

A colloid is a finely divided solid material — or in the case of drilling fluids, a dispersed phase that may be solid, liquid, or gaseous — with individual particle or droplet diameters typically below 2 microns (2,000… Read more →

What Are Colloidal Solids? Colloidal solids (also called colloidal particles or the colloidal fraction) are the ultrafine clay and polymer particles in a water-based drilling fluid that are small enough — typically less… Read more →

What Is a Combi BOP? Combi BOP (also called a combination blowout preventer or CT BOP stack) is a compact, integrated well-control stack designed specifically for coiled tubing and wireline well intervention operations.… Read more →

What Does Come Out of the Hole Mean? Come out of the hole (abbreviated COOH ) is the drilling operation of pulling the drill string, completion string, or other tubulars upward from total depth (TD) to surface —… Read more →

What Is a Commercial Rate? Commercial rate is the minimum production flow rate from a well or reservoir that is economically sufficient to justify the full lifecycle cost of drilling, completing, and producing the… Read more →

What Is a Commingled Completion? Commingled completion is a well completion design that produces from two or more separate reservoir intervals simultaneously through the same wellbore and tubing string — without… Read more →

What Is Commingled Flow? Commingled flow (also called commingled production) is the simultaneous production of reservoir fluids from two or more distinct geological intervals, formations, or zones through a single… Read more →

What Is a Common Depth Point? Common depth point (also called CDP, common midpoint, or CMP) is the subsurface reflection point shared by multiple seismic source-receiver pairs that have different offsets but the same… Read more →

What Is a Common Midpoint? Common midpoint (CMP), also called common depth point (CDP) in older literature, is the surface location exactly halfway between a seismic source and a receiver such that multiple… Read more →

What Is the Common Midpoint Method? Common midpoint method (also called the CMP method or CDP method) is the standard seismic data acquisition and processing technique introduced by W. Harry Mayne in 1962 in which… Read more →

What Is a Common Reflection Point? Common reflection point (also called CRP or true reflection point) is the location in the subsurface where a seismic wave traveling down from a surface source reflects off a geological… Read more →

What Is a Common-Offset Gather? Common-offset gather (also called a constant-offset section or common-offset section) is a collection of all seismic traces recorded at the same source-to-receiver distance — the offset —… Read more →

What Is a Common-Receiver Gather? Common-receiver gather (also called a receiver gather or common-geophone gather) is a collection of all seismic traces recorded by a single receiver station — a geophone group on land,… Read more →

What Is Communitization? Communitization (also called pooling in many jurisdictions) is a contractual or regulatory arrangement that combines two or more separately owned tracts of land or mineral rights into a single… Read more →

What Is Compaction? Compaction (also called formation compaction or reservoir compaction) is the reduction in pore volume of a reservoir rock caused by increasing effective stress, which occurs either as reservoir fluid… Read more →

What Is a Compaction Correction? Compaction correction (also called density correction or Delta-rho correction) is an adjustment applied to formation density log readings to account for the degraded contact between the… Read more →

What Is a Company Man? Company man (also called company representative, wellsite supervisor, or company rep) is the operating company's senior on-site representative at a drilling or workover rig, responsible for… Read more →

What Is a Reservoir Compartment? Reservoir compartment (also called a pressure compartment or hydraulic compartment) is a discrete volume of reservoir rock that is hydraulically isolated from adjacent reservoir volumes… Read more →