Discover the IHRDC Energy Glossary_beta

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J

J factor

The pseudogeometrical factor — the fraction of an induction or laterolog reading contributed by the invaded zone.

J slot

A J-shaped slot and pin arrangement that converts rotation and vertical movement of the string into setting or releasing a tool.

J-T valve

A valve which is designed to cause a pressure reduction when gas flows through it. The temperature drop which accompanies the pressure reduction is called the Joule-Thompson (J-T) effect.

jack

A portable lifting device used for raising heavy loads a short distance.

jack-up rig

An offshore rig with retractable steel legs that are placed on the ocean floor to raise the rig above the water line.

jacket

A component through which heating or cooling fluid can be circulated to control the temperature of materials inside a reactor.

jacketed tank

A tank that is covered with an insulating material.

jackhammer

A heavy-duty pneumatic tool used for large scale demolition work. Also called a paving hammer, a pavement breaker, or an air drill.

jacking

Raising or turning a heavy component with a jack, done on turbines to prevent shaft sag.

jacking bolt

A bolt used to push a component into position during alignment.

jacking frame

A support structure that carries the injector head and pressure control stack above the wellhead on a coiled tubing job.

jackup

A mobile offshore drilling unit that floats to location and then jacks its hull up above the sea on legs planted on the seabed.

jar

A downhole tool that stores energy and releases it suddenly, delivering a hammer blow to free stuck pipe.

jar test

A pilot test in which a mud sample is shaken with water in a jar to see whether its solids are water-wet.

jargon

Specialist vocabulary that excludes anyone outside the group using it.

jet

A tungsten carbide nozzle in a drill bit that accelerates drilling fluid into a high-velocity stream to clean the cutters and the hole bottom.

jet cutter

A shaped charge run on wireline to cut tubing or casing from the inside by explosive jet.

jet hopper

A funnel with a jet nozzle beneath it that draws dry additives into the circulating mud by the venturi effect.

jet mixer

A mixer that uses an eductor, or jet, instead of an impeller to mix low-viscosity liquids.

jet nozzle

The replaceable orifice in a bit face through which drilling fluid exits at high velocity.

jet perforating

Perforating with shaped explosive charges, whose focused jets cut through casing, cement and into the formation.

jet pump

A type of pump that has no moving parts, but uses energy conversions to cause flow in a fluid system.

jet velocity

The speed at which drilling fluid leaves the bit nozzles.

jet-type reactor

A reactor in which nozzles supply the velocity needed to thoroughly mix the reactants with the catalyst.

jetting

Using a high-velocity fluid stream to cut, clean or stir.

jetting action

The cleaning or cutting effect of a high-velocity fluid stream.

jetty

A barrier that reduces turbulence and diverts suspended solids from a facility's water intake area.

job analysis

Establishing systematically what a job actually involves and requires.

job and task analysis

A document that identifies and describes the knowledge and skills that a worker needs to do a job correctly.

job description

A written document that describe the duties, responsibilities, and outcomes needed from a position, along with required qualifications, reporting relationships and other relevant factors.

job design and redesign

Shaping the content and scope of a role, which affects both output and motivation.

job fit

The match between a person's capability and motivation and what a role requires.

A systematic study that involves observing a job; identifying ergonomic risk factors present in various steps of the job; and evaluating the duration, frequency and magnitude of ergonomic risk factors to determine if an MSD hazard is present.

job level requirement or job level required (JLR)

An indication of the expected level of performance of an employee in carrying out a specified task: Awareness (Level 1), Basic Application (Level 2), Skilled Application (Level 3) and Mastery (Level 4).

job offer

The formal proposal of employment, which on acceptance forms a contract.

job rotation

Teaches current employees how to do various jobs over time. They rotate around to different jobs within the organization, performing different tasks unrelated to their original job, exposing them to new knowledge, skills, and perspectives.

job search

The organized process of finding and securing a suitable role.

job sharing

Two part-time employees covering one full-time role between them.

joint

A joint is a break, or fracture, of natural origin in a layer or body of rock that lacks visible or measurable movement parallel to the surface, or plane, of the fracture.

joint interest petroleum agreement

Any agreement governing co-owners of a petroleum interest, of which the JOA is the standard form.

joint operating agreement (JOA)

An agreement governing the rights and obligations of co-owners (participating or working interest owners) in a field or undeveloped acreage, defining how costs and revenues are shared, who is the operator, the operator's responsibilities including marketing production and accounting for costs, and the options available to other parties to replace the operator.

joint set

A joint set is a family of parallel, approximately evenly spaced joints that can be identified through the mapping and analysis of their orientations, spacing, and physical properties.

joint system

A joint system consists of two, or more, intersecting joint sets.

joint venture agreement

The special purpose partnership agreement that is executed by two or more working interested owners in an exploration/development project.

joints

A joint is a break, or fracture, of natural origin in a layer or body of that lacks visible or measurable movement parallel to the surface, or plane, of the fracture. Although joints can occur singly, they most frequently appear as joint sets and systems.

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