Oil and Gas Terms Beginning with “K”

The K coefficient is a fundamental temperature-dependent parameter in spontaneous potential (SP) log interpretation that relates the electrochemical potential developed across a permeable formation interface to the… Read more →

KB (Kelly Bushing) is the depth reference datum used in oil and gas drilling and well logging, defined as the elevation of the rotary kelly bushing — the square or hexagonal drive mechanism on the rig floor through… Read more →

The Kirchhoff equation is the mathematical representation of the fundamental wave physics principle that the wavefield at any given point in space and time can be expressed as the superposition of contributions from… Read more →

Kirchhoff migration is a seismic imaging algorithm that reconstructs a true reflectivity image from recorded seismic data by summing (integrating) amplitudes along computed diffraction hyperbola curves for each output… Read more →

The Koch curve is a strange mathematical shape that looks like a snowflake when you draw it. It is built by taking a straight line, replacing the middle third with two sides of a small triangle, and then repeating that… Read more →

K-means cluster analysis is an unsupervised machine learning algorithm that partitions a dataset into a predetermined number of clusters (k) by iteratively grouping data points around cluster centers (centroids) until… Read more →

Kaolinite is a two-layer (1:1) hydrous aluminum silicate clay mineral with the chemical formula Al2Si2O5(OH)4, composed of alternating sheets of silica tetrahedra and aluminum-oxygen-hydroxyl octahedra held together by… Read more →

Karst is a distinctive type of topography that develops where soluble bedrock, most commonly carbonate rocks such as limestone and dolomite but also evaporites like gypsum and halite, is progressively dissolved by… Read more →

What Is a Kelly? A kelly transmits rotational torque from the rotary table to the drill string by sliding vertically through a matching drive bushing in the master bushing while its flat-sided profile prevents it from… Read more →

What Is a Kelly Bushing? The kelly bushing fits inside the master bushing of the rotary table and grips the kelly to transmit rotation from the table to the drill string, while simultaneously serving as the universal… Read more →

Kelly down is a drilling operations condition that occurs when the kelly (the long, polygonal cross-section steel bar -- typically 40 to 54 feet long, square or hexagonal in cross-section -- that transmits rotary motion… Read more →

The kelly hose (also called the rotary hose, mud hose, or drilling hose) is the large-diameter high-pressure flexible hose that connects the standpipe (the rigid vertical pipe mounted to the derrick that carries… Read more →

A kelly spinner (also called a spinning wrench or rotary spinner) is a pneumatically or hydraulically powered device mounted on the drill floor that grips the kelly and rapidly rotates it to spin up or spin off (thread… Read more →

Kerogen is the insoluble, high-molecular-weight solid organic matter dispersed in fine-grained sedimentary rocks that serves as the precursor to oil and gas upon burial and thermal maturation, classified into four types… Read more →

A keyseat is a narrow groove or slot worn into the borehole wall at a dogleg or curved section of the wellbore by the repeated lateral cutting action of rotating drill pipe tool joints against the formation, creating an… Read more →

What Is kh? kh (permeability-height product, also called flow capacity) is the product of a formation's permeability (k, in millidarcies) and its net pay thickness (h, in feet or metres), representing the reservoir's… Read more →

What Is a Kick? A kick is the unplanned influx of formation fluids into the wellbore that occurs when formation pore pressure exceeds the hydrostatic pressure exerted by the fluid column in the wellbore . Kicks develop… Read more →

In well control, a kill is the process of restoring hydrostatic pressure control to a wellbore that has experienced a kick by circulating weighted kill mud through the well at a controlled rate, replacing formation… Read more →

What Is a Kill Line? A kill line is the high-pressure steel pipe that connects one or more dedicated outlets on the blowout preventer (BOP) stack directly to the rig's high-pressure mud pumps, providing an alternative… Read more →

A kill pump is a high-pressure positive-displacement pump dedicated to well-control operations, used to circulate kill-weight fluid into a well in order to regain hydrostatic control after an influx, or kick, of… Read more →

What Is Kill Weight Fluid? Kill weight fluid is a drilling or workover fluid formulated to a specific density sufficient to generate hydrostatic pressure that equals or slightly exceeds formation pore pressure at total… Read more →

Kill-weight fluid in well control is a drilling mud or specialized fluid formulated to a density sufficient to exert hydrostatic pressure at the bottom of the wellbore equal to or slightly above the formation pore… Read more →

The kilogram per cubic metre, written kg/m3, is the SI unit of density, expressing the mass in kilograms contained in one cubic metre of a substance. In the drilling and well-control side of the oil and gas business it… Read more →

The kilopascal, symbolized kPa, is the working pressure unit across the Western Canadian Sedimentary Basin because Canada reports oilfield data in SI metric units rather than imperial. One kilopascal equals 1,000… Read more →

In oil and gas engineering, kinetic effect refers to the influence of fluid flow velocity on pressure, phase behavior, and chemical reaction rates — appearing in several distinct technical contexts including wellbore… Read more →

Liquid condensed by a scrubber following a compression and cooling process. Read more →

Kriging is a geostatistical interpolation method that estimates the value of a spatially varying property (such as porosity, permeability, formation thickness, or reservoir top depth) at unsampled locations using a… Read more →

The weights assigned to control points in kriging operations to minimize the variance, thus eliminating systematic estimation errors. Read more →

Kurtosis in petroleum geoscience and engineering statistics is the fourth standardized moment of a probability distribution, measuring the "tailedness" or peakedness of the distribution relative to a normal (Gaussian)… Read more →