Glossary

The second ring-shaped space between casing strings in a well, counting outwards from the tubing.

The approved budget document for a well or project.

The defined way one software system asks another for data.

The tools at the bottom of the drill string: bit, motor, stabilisers and measurement tools.

The fluid pressure measured at the bottom of the well.

A short-range radio standard used by battery-powered tags.

The list of parts that make up a piece of equipment.

The fraction of water and solids in produced liquid.

A log run inside casing to judge how well the cement behind it is bonded.

Training delivered through software rather than a classroom.

Site surveillance cameras on a private network.

The main component of natural gas and a potent greenhouse gas when released unburned.

The system that holds work orders, maintenance plans and equipment history.

How bad it would be if a specific piece of equipment failed.

An electrical method of preventing corrosion on buried or submerged metal.

A data structure that lets offline devices merge their changes without losing edits.

X-ray scanning that produces cross-sectional images, used here on rock core.

Fitting a curve to a well’s falling production to estimate what it will produce in total.

The computer system that runs a process plant’s automatic control.

The report a rig files every day describing what was done and what went wrong.

A network segment placed between two networks so neither connects to the other directly.

Whether data is complete, correct, timely and consistent enough to rely on.

How long sound takes to travel a fixed distance through rock, used to estimate rock strength.

The effective mud weight the formation feels while fluid is being pumped.

Injecting gas, chemicals or heat to recover oil that pressure support alone will not.

The mathematical model describing how a reservoir fluid behaves at different pressures and temperatures.

The summary report written after a well is finished.

The corporate system holding finance, procurement and materials.

A pump run on an electric motor set deep in the well to lift fluid to surface.

When a vehicle or delivery is expected to arrive.

The process of moving data from one system to another and reshaping it on the way.

The total volume a well or field is expected to produce over its life.

The plan for how a field will be drilled, produced and built out.

A calculation that breaks a vibration signal into the frequencies it contains.

A machine-learning method where two models compete to produce realistic synthetic data.

How much gas is present relative to liquid in a flowing stream.

The volume of gas produced with each volume of oil.

A log measuring natural radioactivity, used mainly to tell shale from sand.

The screen an operator uses to see and control a process.

The function responsible for keeping people and the environment safe.

The body whose bit-wear grading system the industry uses.

Software that watches network traffic for signs of attack.

Sending a tool through a pipeline to measure wall thickness and find defects.

A room where several departments monitor operations from the same information.

Any measure that raises recovery beyond what the current plan would achieve.

The curve describing how much a well flows at a given bottom-hole pressure.

Light beyond the visible range, used by thermal and gas imaging cameras.

A written assessment of the hazards in a task before it starts.

A number a team agrees to be judged by.

The standard unit of electrical energy consumption.

The programme of surveying a site for leaks and fixing them.

The lowest gas concentration in air that can ignite.

Recorded conclusions from past jobs, intended to stop a problem repeating.

A model trained on text that can read and write natural language.

The system that tracks training courses and competency records.

The procedure for physically isolating equipment before someone works on it.

Measuring formation properties with tools in the drill string while drilling.

The highest pressure a well’s annulus may safely be allowed to reach at surface.

Depth measured along the well path, which is longer than the vertical depth in a deviated well.

Keeping one agreed, authoritative version of core records like wells and equipment.

Corrosion driven by bacteria, often causing localised pits rather than even wall loss.

The pressure above which injected gas mixes fully with reservoir oil.

A standard unit of gas flow rate.

A control method that uses a process model to choose the next action.

Drilling with a closed circulating system so bottom-hole pressure can be controlled precisely.

A meter that measures oil, water and gas rates without separating them first.

How much energy the bit uses to remove a unit volume of rock — lower is more efficient.

The average running time between one failure and the next.

The density of the drilling fluid, which sets the pressure it exerts on the formation.

A log that estimates pore space by measuring how the rock scatters neutrons.

Rig time that produces no hole: waiting, fixing, or recovering from a problem.

The value of a project’s future cash flows expressed in today’s money.

Turning a picture of text into text a computer can search.

The pipe used in wells: casing, tubing and drill pipe.

A camera that makes escaping hydrocarbon gas visible.

The UN-backed framework for measuring and reporting methane emissions.

An industry-standard data model intended to make upstream data portable between vendors.

The control systems and networks that run physical processes, as distinct from office IT.

The engineering drawing showing every pipe, valve and instrument in a process.

The optimistic case: a 10% chance the true value is higher.

The middle case: equally likely to be above or below.

The conservative case: a 90% chance the true value is higher.

A drill bit type with fixed diamond cutters rather than rolling cones.

Maintaining equipment based on its measured condition rather than on a calendar.

How much a well produces for each unit of pressure drawdown.

How likely a piece of equipment is to fail in a given period.

Helmets, gloves, glasses and other gear worn to reduce injury risk.

The measured range of grain sizes in a formation sample, which sets sand-control design.

Interpreting how pressure changes after a rate change, to learn about the reservoir.

The formal authorisation required before hazardous work begins.

A measure of drilling fluid thickness caused by solids content.

Laboratory study of how a reservoir fluid behaves as pressure and temperature change.

A website that installs like an app and works offline.

Answering a question by first retrieving relevant documents, then writing an answer grounded in them.

Setting inspection priorities by how likely and how serious a failure would be.

Investigating why something failed rather than only what failed.

A log measuring rock density, used to estimate porosity.

How fast the bit drills, usually in metres per hour.

How fast the drill string or a machine shaft is turning.

A system that tracks where tagged people and equipment are on a site.

How much service time a component has left before it needs replacing.

A measure of how easily a liquid hydrocarbon evaporates, which sets storage and export limits.

The system that monitors and controls equipment spread across a wide area.

Pressure in a well annulus that rebuilds after being bled off, indicating a leak in a barrier.

Energy used per unit of output, such as kilowatt-hours per barrel.

The standard file format for storing seismic data.

A microscope that images rock structure far below the resolution of light.

Further training a model on labelled examples of the task you want it to do.

A number describing how much damage or improvement exists right around the wellbore.

The identifier for a distinct item held in inventory.

The pump pressure measured at surface on the drilling fluid line.

The beam-pump system that lifts oil using a rod string driven from surface.

The pressure at the top of the production tubing, at surface.

A database designed to store and query billions of timestamped sensor readings efficiently.

Straight-line depth below the surface reference, regardless of how the well path curves.

A drone used here for inspection at height.

How much load a rock sample carries before it crushes.

The single code that identifies a well unambiguously across systems.

A display of acoustic waveforms used alongside the bond log to evaluate cement.

Estimating flow rates from pressure and temperature instead of a physical meter.

A model that understands images and text together.

The curve describing the pressure needed to lift fluid up the tubing at a given rate.

How much fluid is injected compared with how much is produced, at reservoir conditions.

An electrical drive that lets a motor run at adjustable speed.

The temperature at which wax starts to come out of the oil and stick to the pipe wall.

The standard format for exchanging drilling data between systems.

How much of the drill string’s weight is pressing down on the bit.

A measure of a drilling fluid’s ability to carry cuttings up the hole.