Oil and Gas Terms Beginning with “E” — Page 2

In rock mechanics and geophysics, elastic refers to the property of a material to deform reversibly under applied stress and return to its original shape and volume when the stress is removed — analogous to the behavior… Read more →

Elastic constants are the quantitative parameters that define the relationship between stress (applied force per unit area) and strain (resulting deformation) in an elastic material — describing how stiff, compressible,… Read more →

Elastic deformation is a temporary, fully recoverable change in the shape or volume of a rock or material caused by an applied stress, where the body returns exactly to its original geometry once the stress is removed.… Read more →

The elastic limit is the maximum stress a material can withstand and still return to its original shape once the load is removed. Below the elastic limit a material deforms elastically, meaning the strain is fully… Read more →

Elastic neutron scattering is a fundamental nuclear interaction in which a neutron collides with an atomic nucleus and the kinetic energy lost by the neutron in the collision is transferred to the nucleus as additional… Read more →

A seismic or acousticwave, such as a P-wave. Read more →

Electric gas-lift valves are a category of intelligent completion components that replace conventional pressure-operated or differential-pressure-operated gas-lift valves with electronically controlled actuators that… Read more →

An electric probe in production logging is a miniature sensor positioned at the tip of a production logging tool that measures the local electrical conductivity or resistivity of the fluid phase contacting the probe… Read more →

What Is an Electric Submersible Pump? Electric submersible pump (also called an ESP , submersible electric pump, or downhole electric pump) is a multistage centrifugal pump system installed inside the production tubing… Read more →

Electrical anisotropy is a difference in electrical resistivity measured in different directions within a formation — most commonly the difference between the horizontal resistivity (Rh, measured in the direction… Read more →

Electrical conductivity is the property of a material that quantifies its ability to support the flow of electrical current — providing the foundational electromagnetic property that underlies most electrical… Read more →

(noun) A corrosion monitoring device consisting of a metallic element exposed to the process environment, with electrical resistance measurements taken periodically to quantify metal loss due to corrosion. Unlike… Read more →

The electrical double layer (EDL) in petroleum engineering is the charge structure that forms at the interface between a charged solid surface (mineral grain, clay platelet, or wellbore wall) and an adjacent electrolyte… Read more →

(noun) A downhole or inline sensor that measures the electrical impedance of a multiphase fluid mixture to determine the fraction of each phase (oil, water, gas) present at a specific point. The probe exploits the… Read more →

An electrical log is a wireline log of formation resistivity produced by a simple, unfocused arrangement of current-emitting and potential-measuring electrodes that measures the electrical resistance of rock and pore… Read more →

The ability of a material to store a charge from an applied electrical field without conducting electricity. Read more →

An electrical resistance (ER) probe is a corrosion monitoring instrument that measures the rate of metal loss in a pipeline, pressure vessel, or process system by continuously tracking the electrical resistance of a… Read more →

Electrical resistivity is the intrinsic ability of a material to resist the flow of electric current, measured in ohm-metres and defined as the reciprocal of electrical conductivity. In petrophysics it is the single… Read more →

What Is an Electrical Stability Test? Electrical stability test (also called ES test or emulsion stability test) is a quality control measurement performed on oil-based muds (OBM) and synthetic-based muds (SBM) that… Read more →

An electrical survey (ES) is a historical formation evaluation technique — and in current usage, a generic term for wireline logging measurements that use electrical current or electromagnetic fields to characterize… Read more →

An electrode device in well logging is a resistivity logging tool based on an arrangement of one or more metallic electrodes that inject direct current or low-frequency alternating current (below approximately 500 Hz)… Read more →

An electrode resistivity log measures formation resistivity by passing direct (galvanic) current between metal electrodes on the logging tool and either the formation rock or a remote surface return electrode, with the… Read more →

An electrodynamic brake in drilling operations is a regenerative or dissipative braking system installed on a rotary drilling rig's draw works that converts the kinetic energy of the traveling block, drill string, and… Read more →

Electrokinetic potential (also called zeta potential) is the electric potential at the shear plane — the boundary between the mobile diffuse layer of ions surrounding a charged particle and the immobile layer of ions… Read more →

An electromagnetic caliper is a downhole logging tool that uses electromagnetic principles (eddy current induction or magnetic flux leakage) to measure the internal diameter and wall condition of steel casing without… Read more →

Electromagnetic heating for enhanced oil recovery applies radiofrequency (RF) or microwave electromagnetic energy to the reservoir via a downhole antenna or electrode array to heat viscous oil in situ through dielectric… Read more →

What Is the Electromagnetic Method? The electromagnetic (EM) method encompasses geophysical survey techniques that measure the Earth's electrical properties — resistivity, permittivity, and permeability — by recording… Read more →

Electromagnetic propagation in oilfield logging refers to logs that measure formation properties through the propagation characteristics of electromagnetic waves traveling through the formation — distinguished from… Read more →

What Is Electromagnetic Propagation Measurement? Electromagnetic propagation measurement (EPM, also called the dielectric log or microwave propagation log) is a borehole logging technique that measures the propagation… Read more →

Electromagnetic thickness is the remaining pipe wall thickness inferred from the response of eddy currents or pulsed electromagnetic fields induced in casing or tubing walls, where the magnitude and decay… Read more →