Oil & Gas Operations Glossary
Wellheads, artificial lift, separators, tank batteries, gathering, and upstream/midstream field operations. 273 terms in this topic - each defined in plain English on its own page.
This is the field vocabulary of upstream and midstream oil and gas: wells and artificial lift, separation and tank batteries, gathering systems and pipelines, and the production accounting that turns measurements into statements. The automation angle runs through all of it - most of these terms name the thing a SCADA point ultimately watches. Terms specific to fiscal measurement live in Flow & Custody; terms specific to rotating equipment mechanics live in Process Equipment.
273 Terms
What is the 100 mV cathodic protection criterion?
How the 100 mV polarization and depolarization CP criterion proves protection where fixed thresholds fall short.
Read → GlossaryWhat Is Acid Fracturing?
Carbonate stimulation above fracture pressure where etched fracture faces, not proppant, provide conductivity.
Read → GlossaryWhat Is a Fluid Level Shot?
The acoustic gas-gun survey that measures annular fluid level to find pump submergence and guide pump-off optimization.
Read → GlossaryWhat Is Adjust-on-Arrival Plunger Lift Control?
The closed-loop strategy that tunes shut-in time from the last arrival velocity to hold the plunger in a target window.
Read → GlossaryWhat Is an Air-Assisted Flare?
A forced-draft blower supplies combustion air for smokeless burning, with VFD blower speed tied to vent-gas flow.
Read → GlossaryWhat is allocation by difference in oil and gas?
How an unmetered stream like fuel, flare, or shrinkage is derived as inlet minus outlet - and why it absorbs the error.
Read → GlossaryWhat Is an Allocation Factor?
The ratio of measured total to summed theoretical rates, why it drifts from 1.0, and what that drift signals.
Read → GlossaryWhat Is Allocation Metering?
How a commingled custody volume is apportioned back to individual wells or shippers using well tests.
Read → GlossaryWhat is analyzer sample lag time in gas quality measurement?
The transport delay from sample tap to detector; uncompensated it misaligns heating value against the volume it multiplies.
Read → GlossaryWhat is Annulus Pressure Monitoring on an Injection Well?
Continuous tubing-casing annulus pressure that flags packer or tubing leaks in real time between MITs.
Read → GlossaryWhat Are Arps Decline Curve Equations?
The b-exponent and Di parameters behind exponential, hyperbolic, and harmonic decline, and what b reveals about drive.
Read → GlossaryWhat Is Artificial Lift?
How wells are pumped or gas-lifted to surface once natural flow fades - ESP, rod pump, gas lift, PCP, and plunger lift compared.
Read → GlossaryWhat Is Back-Allocation?
How a measured sales total is distributed to wells using well-test theoretical rates and an allocation factor.
Read → GlossaryWhat Is a Downhole Pump Barrel and Plunger?
The cylinder-and-piston core of a rod pump, insert vs tubing, tying fit and clearance to efficiency.
Read → GlossaryHow do you baseline lift casing pressure?
Record the normal casing pattern and context on a stable well so later deviations flag loading, gas, or lift problems.
Read → GlossaryBiogas Gas-Quality Monitoring
The methane, hydrogen sulfide, and moisture signals that protect engines and gate biogas for use.
Read → GlossaryWhat Is a Blowout Preventer (BOP)?
The stack of ram and annular valves that seals a well in a kick - well control, the accumulator, and monitoring.
Read → GlossaryWhat Is a BOP Accumulator (Koomey Unit)?
Nitrogen-precharged bottles that store hydraulic energy to close the BOP even without rig power.
Read → GlossaryWhat Is Bottomhole Pressure?
Flowing vs static BHP, how it is measured, and why drawdown drives production and lift decisions.
Read → GlossaryWhat Is Brittle Fracture in Storage Tanks?
How a tank shell can rupture at low temperature under stress, and how MDMT and fill-rate limits guard against it.
Read → GlossaryWhy does cal-gas tubing need purging and short runs?
Dead volume and wall adsorption suppress and delay reactive gases, landing a rushed span calibration low.
Read → GlossaryWhat Is a Cashout Gas Imbalance Settlement?
How a pipeline settles a monthly imbalance in cash at penalty-tiered prices, and how real-time tracking avoids it.
Read → GlossaryWhat Is Well Casing?
The cemented steel strings that line and seal a wellbore - surface, intermediate, and production casing explained.
Read → GlossaryWhat Is a Casing Centralizer?
How bow-spring and rigid centralizers keep casing centered for a uniform, channel-free cement sheath.
Read → GlossaryWhat Is a Casing Head?
The base wellhead spool that suspends casing strings, seals casing annuli, and anchors the stack.
Read → GlossaryWhat Is Casing Head Pressure in Gas Lift?
How surface injection pressure reveals which gas-lift valve is passing and how deep a well is really lifting.
Read → GlossaryHow do you analyze a casing head pressure trend?
Read CHP over time to tell gas-lift swings from creeping leaks, set rate-of-change alarms, and correlate with tubing pressure.
Read → GlossaryWhat Is a Casing Shoe & Shoe Track?
The float shoe, float collar, and shoe track that trap contaminated cement, plus the shoe integrity test.
Read → GlossaryHow do you size fuel gas for a catalytic heater?
Match heater BTU output to a cabinet's winter heat loss, then convert to gas SCF/day or watts without freezing instruments.
Read → GlossaryWhat Is Cathodic Protection?
The electrochemical defense that stops external pipeline corrosion.
Read → GlossaryWhat is crusher choke feed control?
The feedback loop that keeps a crusher cavity full for product shape and liner life, tuned in SCADA.
Read → GlossaryWhat Is a Choke Valve?
The wellhead valve that sets each well's production rate and drawdown.
Read → GlossaryWhat Is a Christmas Tree?
The oil and gas production tree - master, wing, and swab valves that control flow from a well - explained, with surface vs subsea.
Read → GlossaryWhat Is a Class Location?
How gas operators count structures along a sliding mile to set Class 1-4 and the pressure a line may carry.
Read → GlossaryHow do you close out a well test to allocation?
Read totals against the stable start, correct volumes to reference conditions, compute rates, sanity-check against history, and record the result.
Read → GlossaryWhat Is a Coalescer?
The fine-polishing device that merges sub-micron droplets and aerosols to dry gas or separate oil and water.
Read → GlossaryWhat Is Coiled Tubing?
The continuous reeled steel tube that runs live-well cleanouts, milling, and stimulation in well services.
Read → GlossaryWhat Is a Coiled Tubing Unit?
The reel, injector head, and control cabin spread that runs continuous tubing for live-well interventions.
Read → GlossaryCompressor Station
A pipeline facility that re-boosts natural gas pressure to keep it flowing through gathering and transmission systems.
Read → GlossaryWhat Is Condensate?
The light volatile liquid that drops out of gas at the wellhead or separator - how it forms, and how it differs from crude and NGLs.
Read → GlossaryWhat Is Condensate RVP Control in Stabilization?
Driving a stabilizer to a target Reid vapor pressure via reboiler duty and bottoms temperature so product is safe to ship.
Read → GlossaryWhat is a corrosion access fitting?
The high-pressure hardware that lets crews insert and retrieve coupons and probes on a live line without shutdown.
Read → GlossaryWhat Is a Corrosion Allowance?
The sacrificial extra wall thickness in pipe and vessel design consumed by corrosion over service life.
Read → GlossaryWhat Is a Corrosion Coupon?
The pre-weighed metal strip whose weight loss gives an internal corrosion rate in mils per year.
Read → GlossaryWhat Is a Corrosion Inhibitor?
The film-forming chemical injected into wells and pipelines to slow internal corrosion.
Read → GlossaryWhat is corrosion rate in mils per year (MPY)?
The wall-loss speed in thousandths of an inch per year that drives remaining-life and inspection-interval decisions.
Read → GlossaryWhat Is Corrosion Under Insulation (CUI)?
The hidden external corrosion that attacks insulated piping where moisture is trapped under jacketing.
Read → GlossaryWhat is a CP groundbed (anode bed)?
The buried anode array that discharges impressed CP current, its materials, resistance, and replacement signals.
Read → GlossaryWhat Is Cryogenic Gas Processing?
The cryo route for deep NGL recovery, cold boxes, ethane recovery versus rejection, and cold-end monitoring.
Read → GlossaryWhat Is a Daily Production Report in Oil and Gas?
The end-of-gas-day artifact: per-well oil, gas, water, run tickets, downtime codes, and comments feeding accounting.
Read → GlossaryWhat is datum depth correction for bottomhole pressure?
Adjusting pressures from different gauge depths to a common reference so wells and depletion trends compare fairly.
Read → GlossaryWhat Is Decline Curve Analysis?
The Arps method for forecasting production and reserves, built on clean, continuous production history.
Read → GlossaryWhat Is a Demethanizer Column?
The cold distillation tower that splits methane to sales gas from heavier NGLs in a cryo plant.
Read → GlossaryWhat Is Destruction and Removal Efficiency?
The required percentage of VOC or methane a control device destroys - the 98/95% compliance targets.
Read → GlossaryWhat is dew point margin in gas quality control?
The buffer between measured dew point and the coldest downstream temperature, trended to catch a failing dehydration bed.
Read → GlossaryWhat Is Direct Assessment?
The four-step survey-and-dig method that proves integrity on unpiggable lines, including ECDA, ICDA, and SCCDA.
Read → GlossaryWhat Is a Downhole Gas Separator?
The tool that diverts free gas away from a pump intake to prevent gas lock - across rod-pump and ESP types.
Read → GlossaryWhat Is a Downhole Gauge?
Measuring true bottomhole pressure and temperature - permanent vs memory gauges and why it beats surface data.
Read → GlossaryWhat Is a Drag Reducing Agent?
The polymer that cuts pipeline friction to boost throughput.
Read → GlossaryWhat Is Drilling Mud Weight?
The fluid density that sets hydrostatic pressure and must stay inside the pore-pressure to fracture window.
Read → GlossaryWhat Is a Separator Dump Valve Cycle Count?
How counting dump cycles predicts seat wear and flags foaming, undersized valves, or level-controller mistuning.
Read → GlossaryWhat Is a Dynamometer Card?
The load-vs-position plot that diagnoses rod-pump faults - gas lock, fluid pound, and worn valves.
Read → GlossaryWhat is an electric line heater?
The flameless resistance-heated alternative to a fired line heater for sites with no fuel gas or where flames are banned.
Read → GlossaryWhat Is an ER Corrosion Probe?
The online electrical-resistance probe that streams live internal metal-loss data to SCADA.
Read → GlossaryWhat Is an ESP Downhole Sensor?
The gauge below the ESP motor that reports intake pressure, motor temperature, and vibration up the power cable to SCADA.
Read → GlossaryWhat Is ESP Gas Locking?
When free gas fills the pump stages and stops liquid flow, and the separators and signals that fight it.
Read → GlossaryWhat Is an ESP Seal Section?
The protector between an ESP motor and pump that equalizes pressure, blocks well fluid, and carries thrust.
Read → GlossaryWhat Is a Filter Separator?
The two-stage coalescing vessel that strips solids and fine aerosols to deliver dry gas to a meter.
Read → GlossaryWhat Is a Flare Assist Ratio?
The mass of steam or air added per mass of vent gas, tuned between smoking and over-assist off the flow signal.
Read → GlossaryWhat Is Flare Combustion Efficiency?
How completely a flare burns its gas, and the tip velocity, heating value, and assist that degrade it.
Read → GlossaryWhat Is a Flare Gas Flow Meter?
A wide-turndown ultrasonic or thermal meter that measures waste gas from purge to blowdown for emissions accounting.
Read → GlossaryWhat Is Flare Gas Recovery?
Capturing low-pressure vent gas ahead of the flare and returning it to fuel or sales, with proof flaring was avoided.
Read → GlossaryWhat Is a Flare Header?
The relief and blowdown collection piping to the flare, where shared back pressure limits valve capacity.
Read → GlossaryWhat is a flare minimization plan and what does it require operators to report?
A living plan to cut flaring with causal analysis after big events, proven by flare metering and root-cause event tagging.
Read → GlossaryWhat Is Flare Purge Gas and Purge Velocity?
Continuous purge keeps a minimum upward header velocity to stop air ingress and flashback; seals cut how much is needed.
Read → GlossaryWhat Is a Flare Seal Drum?
The liquid seal that blocks flame flashback into the header and lets purge gas be reduced, held by level control.
Read → GlossaryWhat Is a Flare Tip & Pilot?
The burner where relief gas ignites, the continuously lit pilot, and why flame-out is a critical alarm.
Read → GlossaryWhat Is a Flash Tank Separator?
The vessel that flashes vapor out of a liquid by pressure letdown, used as a separation and stabilization stage.
Read → GlossaryFlowback Water
The frac fluid that returns after a well is fractured, how its chemistry shifts, and how it is recovered and managed.
Read → GlossaryWhat is flowing bottomhole pressure (FBHP)?
The pressure at the reservoir face while a well produces, setting drawdown and locating the well on its inflow curve.
Read → GlossaryWhat Is Fluid Pound?
The damaging shock when a plunger slaps a partly filled fluid column, seen as a sharp load drop on the dynamometer card.
Read → GlossaryWhat Is a Frac Hit?
Fracture or pressure communication from a new child well into a nearby producing parent well, detected by offset monitoring.
Read → GlossaryWhat Is a Frac Pack?
A hybrid completion combining a short high-conductivity fracture with a gravel pack for sand control in high-perm sands.
Read → GlossaryWhat Is a Frac Plug?
The downhole tool that isolates a completed stage in plug-and-perf, composite versus dissolvable.
Read → GlossaryWhat Is a Frac Stage?
One isolated interval of a horizontal lateral, perforated and fractured as a unit - and the core dataset for post-frac analysis.
Read → GlossaryWhat Is a Frac Tree?
The high-pressure valve stack above the wellhead that safely delivers a frac, with the goat head and zipper manifold.
Read → GlossaryWhat is a fuel gas conditioning skid?
Packaged skid that scrubs, heats, and regulates fuel gas for a compressor driver, holding superheat above the dew point.
Read → GlossaryWhat Is a Fuel Gas System?
The skid that conditions and supplies clean, dry, regulated gas to engines, heaters, generators, and flare pilots.
Read → GlossaryWhat is full well stream allocation?
Dividing an unseparated multiphase stream back to individual wells using well tests.
Read → GlossaryWhat is a gas analysis report and how is it used in allocation?
The composition and heating value report that drives energy allocation, where sampling cadence quietly governs accuracy.
Read → GlossaryWhat Is a Gas Anchor?
The downhole separator that keeps free gas out of a rod pump to stop gas lock and restore fillage.
Read → GlossaryWhat Is a Gas Boot?
The vertical degasser that flashes residual gas out of oil before the stock tank to cut tank vapors and emissions.
Read → GlossaryWhat Is a Gas Filter Coalescer?
The two-stage vessel that filters solids and coalesces fine liquid aerosols to polish a gas stream.
Read → GlossaryWhat did the PHMSA gas gathering rule change?
How Part 192 expanded to more gathering lines, the reporting and safety obligations it created, and who is newly in scope.
Read → GlossaryWhat Is a Gas Imbalance Reconciliation Report?
The monthly workflow reconciling nominations against measured deliveries, with cashout, trading, and aging.
Read → GlossaryWhat Is a Gas Imbalance Statement?
The monthly scheduled-versus-actual record, tolerance bands, cash-out, and trending to zero with SCADA.
Read → GlossaryWhat Is Gas Interference?
How free gas in the pump barrel compresses instead of liquid, robbing displacement and gas-locking the pump.
Read → GlossaryWhat Is Gas Lift?
Lifting oil by injecting compressed gas to lighten the fluid column - valves, mandrels, and continuous vs intermittent - explained.
Read → GlossaryWhat Is Gas Lift Heading Instability?
The cyclic slugging where a gas-lift well swings between loading and unloading, and how to stabilize it.
Read → GlossaryHow Does Gas Lift Injection Rate Optimization Work?
How the gas-lift performance curve sets an optimum injection rate and how SCADA tunes it field-wide.
Read → GlossaryWhat Is a Gas Lift Kickoff?
The higher-than-normal pressure or auxiliary gas needed to break a loaded or dead well loose and start it lifting.
Read → GlossaryWhat Is a Gas Lift Mandrel?
The tubing-mounted pocket housing a gas-lift valve, in conventional and wireline-retrievable side-pocket forms.
Read → GlossaryWhat Is a Gas Lift Orifice Valve?
The operating valve at the deepest injection point, versus the unloading valves, and its stable operating point.
Read → GlossaryWhat Is the Point of Injection in Gas Lift?
Which mandrel actually passes gas, why the deepest single point is the target, and how to locate it.
Read → GlossaryWhat Is a Gas Lift Unloading Sequence?
How injection transfers deeper valve by valve to the operating point, read from casing pressure trends.
Read → GlossaryWhat Is a Gas Lift Valve?
The nitrogen-charged bellows valve that admits injection gas at set depths - unloading sequence and IPO vs PPO explained.
Read → GlossaryWhat Is Gas Lift Valve Spacing Design?
Calculating mandrel depths from injection pressure, fluid gradients, and temperature so each valve uncovers the next.
Read → GlossaryGas Processing Plant
The midstream facility that conditions raw gas into pipeline-quality methane and recovers natural gas liquids.
Read → GlossaryWhat Is a Gas Plant Allocation Statement?
The monthly statement a plant issues each producer: inlet in, products out, fuel and shrink deducted.
Read → GlossaryWhat is a gas quality bank in a commingled pipeline?
A financial ledger reconciling shippers who inject high- and low-BTU gas but all receive average-quality gas at delivery.
Read → GlossaryWhat are gas quality spec compliance limits in a tariff?
The tariff bands for BTU, H2S, sulfur, CO2, water, dew point, and oxygen, rolled into one spec-compliance status.
Read → GlossaryWhat is gas quality tracking across a pipeline?
Following energy content through a pipeline as streams commingle and travel with line-pack delay to assign the right BTU.
Read → GlossaryWhat Is a Gas-Oil Ratio (GOR)?
The standard cubic feet of gas produced per barrel of oil, tracked per well as a reservoir and production diagnostic.
Read → GlossaryWhat Is a Gathering Line Interconnect?
The tie-in where one pipeline connects to another, the custody-transfer meter it creates, and how it is coordinated.
Read → GlossaryGathering System
The network of small pipelines that collects production from individual wells and feeds it to central processing or trunk lines.
Read → GlossaryWhat is a downhole gauge carrier mandrel?
The completion sub that houses and protects a permanent gauge, offered tubing-conveyed or retrievable side-pocket, often dual.
Read → GlossaryGauge Hatch vs Thief Hatch
A plain access opening versus a weighted relief hatch, and when each is required on a tank.
Read → GlossaryHow do you cross-verify a custody GC against a lab sample?
Pulling a spot cylinder sample to a reference lab and reconciling it against the online GC to confirm accuracy.
Read → GlossaryWhat Is Gas-Oil Ratio Back Allocation?
How tested GORs split commingled casinghead gas back to wells by multiplying each well's oil by its GOR.
Read → GlossaryWhat Is a Gravel Pack?
A sand-control method placing sized gravel around a screen to filter formation sand, confirmed by a screen-out pressure rise.
Read → GlossaryWhat Is a High/Low Pilot Shutdown?
The pneumatic pressure pilots that trip a wellhead surface safety valve per API 14C by bleeding the control line.
Read → GlossaryWhat Is a Coating Holiday Detector?
The high-voltage jeep tester that finds pinholes in pipe coatings before burial, where one defect concentrates corrosion.
Read → GlossaryWhat Is Hydraulic Fracturing (Frac)?
Cracking tight rock with high-pressure fluid and holding it open with proppant - stages, plug-and-perf, pressure.
Read → GlossaryWhat is a hydrogen probe?
A device that measures atomic hydrogen flux through steel, giving early warning of sour corrosion and cracking risk.
Read → GlossaryWhat is an imbalance tolerance in gas measurement?
The contractual band a shipper's nominated versus delivered gas can differ before penalties or cashout apply.
Read → GlossaryWhat is in-line gasoline blending control?
Metering refinery components at a header in recipe ratios to make finished fuel on the fly, sequenced to a target volume.
Read → GlossaryWhat is inert content (nitrogen and CO2) in custody gas quality?
How nitrogen and CO2 dilute heating value and Wobbe, why tariffs cap them, and why a rising trend flags an upstream upset.
Read → GlossaryWhat Is an Inlet Separator?
The primary vessel that does the bulk gas-liquid split at a facility or plant inlet - internals, control, and its role.
Read → GlossaryWhat is instant-off potential in cathodic protection?
The IR-drop-free polarized pipe potential, read the instant CP current is interrupted, behind the -850 mV criterion.
Read → GlossaryWhat Is Integrity Management?
The program to keep a line safe: identify threats, assess, remediate, and reassess on risk-based intervals.
Read → GlossaryHow do you read a dyno card shape?
Recognize the full-pump parallelogram, then name fluid pound, gas interference, and a worn pump from the corner shapes.
Read → GlossaryWhat Is a Joule-Thomson (JT) Skid?
The pressure-driven cooling skid that drops out liquids to control hydrocarbon dew point and recover NGLs.
Read → GlossaryWhat Is a Keep-Whole Gas Processing Contract?
A deal where the processor keeps NGL value but must return energy-equivalent gas, driven by the frac spread.
Read → GlossaryWhat Is Kick Detection?
Catching formation fluid entering the wellbore before it becomes a blowout - pit gain, flow-back, and well control.
Read → GlossaryWhat Is Lease Fuel & Flare Accounting?
How gas burned as fuel, flared, or vented on-lease is quantified so produced minus disposed equals sold gas.
Read → GlossaryHow Does Lift Gas Allocation Work Across a Field?
Splitting limited injection gas among wells by marginal oil-per-gas response to maximize total field oil.
Read → GlossaryWhat Is Line Pack?
The compressible gas inventory that makes a pipeline its own buffer store.
Read → GlossaryHow do you line up a test separator for a well test?
Set the header, open the inlet, establish pressure and level control, stabilize, then zero timers and start the timed test.
Read → GlossaryWhat is separator liquid carryover and gas blowby?
The two opposite separator failures: liquid out the gas outlet at high level, and gas out the dump at low level.
Read → GlossaryWhat Is Liquid Loading in a Gas Well?
How falling gas velocity lets liquids pile up in the wellbore, the SCADA symptoms, and how to unload.
Read → GlossaryWhat Is Logging While Drilling (LWD)?
How LWD adds gamma, resistivity, and porosity sensors to the BHA to drive real-time geosteering.
Read → GlossaryWhat Is Lost Circulation in Drilling?
Mud escaping into the formation, its kick risk, LCM cures, and how flow monitoring detects it early.
Read → GlossaryWhat Is Makeup Gas and Imbalance Payback?
How over- and under-delivered owners balance in-kind over time, and the shared record that tracks who is owed.
Read → GlossaryWhat Is MAOP?
The code-established pressure ceiling that governs every pipeline segment.
Read → GlossaryWhat Is Measurement While Drilling (MWD)?
How an MWD tool measures inclination, azimuth, and toolface downhole and pulses the survey up to surface.
Read → GlossaryWhat Is a Mechanical Integrity Test (MIT)?
The annulus pressure test that proves an injection well has no leak between tubing, casing, and packer.
Read → GlossaryWhat is a methane number for fuel gas quality?
A knock-resistance rating for fuel gas, like octane for a gas engine, computed from composition to protect engines.
Read → GlossaryWhat Is Methanol Injection for Hydrate Control?
How methanol suppresses gas hydrates in wet cold lines, and how SCADA flags plugging and injection-pump faults.
Read → GlossaryWhat Is Microbiologically Influenced Corrosion (MIC)?
Corrosion driven by bacteria under deposits on pipe and tank walls, causing hidden pitting that biocides control.
Read → GlossaryWhat is Mineral Scale in Water Injection Systems?
Why dissolved minerals precipitate as hard scale that plugs filters, pumps, and injection wells.
Read → GlossaryWhat Is a Molecular Seal on a Flare?
A density trap below the flare tip that holds a light-gas pocket to block air ingress and flashback into the stack.
Read → GlossaryWhat Are Natural Gas Liquids (NGL)?
Ethane, propane, butane, and pentanes-plus recovered from gas - how they're recovered, fractionated, and why they're valuable.
Read → GlossaryWhat Is NGL Fractionation?
The deethanizer-depropanizer-debutanizer train that splits y-grade NGL into purity products.
Read → GlossaryWhat Is NGL Theoretical Yield Allocation?
Estimating each producer's liquids from GPM times volume, then scaling to the plant's actual recovered barrels.
Read → GlossaryWhat Is Nodal Analysis?
Finding a well's operating point where inflow meets outflow to drive tubing, choke, and lift decisions.
Read → GlossaryWhat Is Nodal Analysis?
Intersecting inflow and outflow curves to find a well's operating point and size its lift method.
Read → GlossaryWhat Are Oil and Grease Limits?
Daily-max and monthly-average caps on produced-water hydrocarbon, and how analyzers and sampling prove compliance.
Read → GlossaryOil-Based vs Water-Based Drilling Mud
Comparing water, oil, and synthetic mud systems on shale inhibition, lubricity, temperature, and disposal cost.
Read → GlossaryWhat Is Opening and Closing Gauge on a Run Ticket?
How a tank haul is documented from opening to closing gauge, gross to net barrels, and the ATG and LACT equivalent.
Read → GlossaryWhat Is a Packer?
The downhole seal that plugs the tubing-casing annulus - zonal isolation, permanent vs retrievable, and leak signs.
Read → GlossaryWhat Is Perforation?
Punching flow paths through casing and cement with shaped charges - shot density, phasing, and plug-and-perf.
Read → GlossaryWhat Is a Perforation Cluster?
A short group of perforations within a stage, the entry point where fractures initiate - and a focus of limited-entry design.
Read → GlossaryWhat is a permanent downhole gauge (PDG)?
An always-on sensor left in the completion that streams bottomhole pressure and temperature to SCADA for the well's life.
Read → GlossaryPhase Imbalance
Unequal three-phase voltages or currents - why a small voltage unbalance overheats motors, and how it is measured and protected against.
Read → GlossaryPig / Pigging
Running a device through a pipeline to clean it, separate products, or inspect the wall for corrosion and defects.
Read → GlossaryWhat Is Pipeline Imbalance and Swing?
The gap between nominated and delivered gas, the intraday swing that creates it, and real-time gas control.
Read → GlossaryWhat Is Pitting Corrosion?
The localized attack that drills deep pits through steel while sparing most of the surface.
Read → GlossaryHow Does Plunger Arrival Detection Work?
The magnetic or acoustic sensor at the lubricator that tells the controller the plunger reached surface and how fast.
Read → GlossaryWhat Is Plunger Lift?
Deliquifying gas wells with a free-traveling plunger and the well's own gas - the cycle, liquid loading, and control - explained.
Read → GlossaryWhat Is a Plunger Lift Cycle?
The shut-in, flow, and afterflow phases that deload a gas well, timed by a controller and tuned via SCADA.
Read → GlossaryWhat Is a Polished Rod?
The topmost smooth rod through the stuffing box, and the load measurement behind dynamometer cards.
Read → GlossaryWhat Is a Pony Rod?
The short sucker rods that space out a rod pump so the plunger strokes correctly within the barrel.
Read → GlossaryWhat is a bottomhole pressure gradient survey?
Stepping a gauge down the well to read pressure at intervals, mapping fluid contacts, levels, and densities.
Read → GlossaryWhat Is Primary vs Check Metering for Allocation?
The allocation-of-record meter versus the meter that verifies it, which governs on disagreement, and live comparison.
Read → GlossaryProduced Water
The brine that comes up with oil and gas, its chemistry, volumes, and how it is separated, recycled, or disposed of.
Read → GlossaryWhat Is Produced Water Accounting?
Tracking per-well water via water cut and tests, reconciling it against disposal meters, and reporting it.
Read → GlossaryWhat is a produced water disposition report?
The accounting of where every barrel of produced water went, closed by tank levels, meters, and digitized hauling tickets.
Read → GlossaryWhat Is Production Allocation?
Why commingled streams metered only at a sales point are split back to wells through the allocation network.
Read → GlossaryWhat Is Production Tubing?
The removable pipe that carries oil and gas to surface inside the casing - tubing vs casing and tubing pressure.
Read → GlossaryWhat Is Pump Fillage?
The percent of the pump barrel filled with liquid each stroke, computed from the downhole card to drive pump-off control.
Read → GlossaryWhat Is PVT Analysis?
The lab study of reservoir fluid behavior that underpins every production forecast, allocation calc, and net-oil setting.
Read → GlossaryWhat is quartz gauge drift in a downhole pressure sensor?
The slow zero and span drift of downhole gauges over years, detected and corrected against shut-in references via historian trends.
Read → GlossaryWhat is a questionable gas quality flag in custody measurement?
The status marker that flags a suspect composition or energy interval after a GC fault and drives measurement editing under API 21.1.
Read → GlossaryHow do you read casing-tubing for lift?
Use the two wellhead pressures and their difference to judge fluid level, loading up, and declining lift performance.
Read → GlossaryHow do you read a gas-lift casing trend?
Tell steady injection from heading, spot valve shifts and lost supply, and read the casing trend with tubing pressure.
Read → GlossaryWhat Is a Real-Time Transient Model?
A live hydraulic model that flags leaks when measured pressures and flows diverge from prediction.
Read → GlossaryWhat is separator residence time control?
Managing level and throughput so oil, water, and gas get enough settling time to separate without carryover.
Read → GlossaryWhat Is a Rod Pump?
Sucker rod (beam) pumping and the pumpjack - how reciprocating rods lift oil, plus dynamometer cards and pump-off control - explained.
Read → GlossaryWhat Is a Run Ticket?
The custody-transfer record of a crude oil sale - what it contains, tank vs LACT tickets, and why it is the basis of payment.
Read → GlossaryHow do you reconcile run tickets to purchaser invoices?
Match each ticket and LACT proving to the settlement statement, anchored in continuous tank and meter data, to catch underpayments.
Read → GlossaryWhat Is Rupture Detection?
The fast recognition of a major pipeline failure for rapid shutdown.
Read → GlossaryWhat Is Sales Gas?
Pipeline-quality gas that meets water, H2S, CO2, dew point, and heating-value specs - and how raw gas gets there.
Read → GlossaryWhat is sales gas dew point control?
Meeting pipeline water and hydrocarbon dew point limits with dehydration and chilling, controlled without over-treating.
Read → GlossaryWhat Is a Separator?
The vessel that splits well fluid into gas, oil, and water - 2-phase vs 3-phase, internals, and level and pressure control - explained.
Read → GlossaryWhat Is a Separator Weir and Weir Height Adjustment?
An overflow baffle that sets the oil-water split by overflow height, trimming the interface and residence time.
Read → GlossaryWhat Is a Separator Well Test?
Measuring one well's oil, gas, and water rates through a test separator, including carryover and stabilization concerns.
Read → GlossaryHow do you set a plunger non-arrival alarm?
Choose an arrival timeout from the well's history, decide the missed-arrival count, and configure a safe well response.
Read → GlossaryWhat is an oil and gas severance tax report?
A state production-tax return on severed oil, gas, and NGL whose volumes should match royalty and production filings.
Read → GlossaryWhat Is a Shrinkage Factor?
The multiplier for oil volume lost as dissolved gas escapes between the wellhead and the stock tank, and how it is applied.
Read → GlossaryWhat Is a Skim Tank?
The first gravity vessel in a water plant, floating residual oil off produced water before disposal.
Read → GlossaryWhat Is Slickline?
The single non-electric wire that runs mechanical downhole jobs - plugs, valves, and memory gauges.
Read → GlossaryWhat Is Slickwater Frac Fluid?
The low-viscosity, friction-reduced water system that dominates shale fracs, pumped at high rate to place proppant.
Read → GlossaryWhat Is a Slug Catcher?
The large inlet buffer - vessel or finger type - that absorbs pipeline liquid slugs to protect a gas plant from surges.
Read → GlossarySour Gas
Natural gas containing hydrogen sulfide, how it differs from sweet gas, the hazards it poses, and how it is sweetened.
Read → GlossaryHow does a speed-of-sound gas quality analyzer work?
Infers heating value and Wobbe index from acoustic velocity, CO2 and pressure for near real-time energy data.
Read → GlossarySpill Containment
The barriers that catch leaks and spills at oil and gas sites, how secondary containment is sized, and the SPCC rules behind it.
Read → GlossaryHow do you spot a tubing leak?
Read the casing-tubing communication signature of a tubing leak and tell it from loading or a pump problem.
Read → GlossaryHow do you spot fluid pound on a card?
Find the load held high then dropping sharply late on the downstroke, and separate it from a rounded gas card.
Read → GlossaryHow do you spot gas on a card?
Find the rounded, gradual downstroke release, tell it from a sharp fluid pound, and confirm against casing pressure.
Read → GlossaryHow do you reconcile a spot sample lab result against the online GC?
Comparing a certified lab sample against the online custody GC quantifies analyzer bias and builds an ongoing, logged proof of accuracy.
Read → GlossaryWhat Is Condensate Stabilizer Reflux Control?
Returning cooled overhead liquid to set the column top temperature and the cut between product and stripped light ends.
Read → GlossaryWhat Is a Standing Valve?
The fixed intake check valve of a rod pump - how it admits and holds fluid through the pump cycle.
Read → GlossaryWhat is static bottomhole pressure (SBHP)?
The stabilized shut-in reservoir pressure that tracks depletion over field life and differs from flowing pressure.
Read → GlossaryWhat Is a Steam-Assisted Flare?
How steam at the flare tip drives smokeless burning, and why over-steaming quenches the flame - a live ratio to trim.
Read → GlossaryWhat Is a Step-Rate Test on an Injection Well?
The field procedure that finds a formation's fracture pressure and sets the injection limit.
Read → GlossaryWhat is stray current corrosion?
How foreign DC and dynamic current discharge off pipelines to cause localized corrosion, and how bonds mitigate it.
Read → GlossaryWhat Is Strokes Per Minute (SPM)?
Pumping speed that, with stroke length, sets a rod pump's displacement, tuned by a VSD to match well inflow.
Read → GlossaryWhat Is a Sucker Rod String?
The column of steel rods that links a pumpjack to the downhole pump - design, grades, and failure.
Read → GlossaryWhat is the difference between surface readout and memory mode downhole gauges?
Surface readout streams data live for SCADA alarming and optimization; memory gauges record internally and are read after retrieval.
Read → GlossarySurface vs Downhole Dynamometer Card
The measured polished-rod card versus the wave-equation pump card used to read fillage, leaks, and gas.
Read → GlossaryWhat is sustained casing pressure (SCP)?
Annular pressure that rebuilds after being bled off, signaling a barrier or cement failure and demanding integrity attention.
Read → GlossarySaltwater Disposal (SWD) Well
A permitted injection well that disposes of produced water underground, monitored for injection pressure, rate, and cumulative volume.
Read → GlossaryWhat Is a Tank Battery?
The lease facility where well production is separated, treated, stored in stock tanks, and measured out - equipment and custody - explained.
Read → GlossaryWhat Is Central Tank Battery Allocation?
How one LACT sales total is split back to commingled wells using each well's tested rate and runtime.
Read → GlossaryWhat Is a Tank Bottom Corrosion Survey?
The MFL floor-scan inspection that maps storage-tank floor corrosion during out-of-service API 653 intervals.
Read → GlossaryWhat Is a Test Separator?
The vessel that isolates one well to measure its individual gas, oil, and water rates for testing and allocation.
Read → GlossaryWhat Is Theoretical vs Actual Allocation?
Why estimated well volumes never match the metered total, and how the factor scales parts to the whole.
Read → GlossaryWhat Is a Thief Hatch?
The hinged tank-top hatch for gauging and sampling that doubles as pressure-vacuum relief - and a top emissions source - explained.
Read → GlossaryWhat is top-of-line corrosion (TLC)?
Internal attack on the upper wall of wet-gas lines where vapor condenses beyond the reach of bottom inhibitor.
Read → GlossaryWhat Is a Traveling Valve?
The moving check valve in a rod pump plunger that lifts the fluid column on every upstroke.
Read → GlossaryWhat Is a Tubing Anchor Catcher?
The downhole slip device that anchors tubing to casing to stop tubing breathing and wear in rod-pumped wells.
Read → GlossaryWhat is instrument tubing bend radius and why does it matter?
The tightest curve a tube can take without kinking, flattening, or restricting the sensing flow inside.
Read → GlossaryWhat Is a Tubing Head?
The wellhead spool that suspends the tubing, seals the tubing annulus, and taps it for monitoring.
Read → GlossaryWhat is tubing head temperature monitoring?
Trending the surface flowing temperature at the wellhead to flag rate changes, hydrate and wax risk, and choke cooling.
Read → GlossaryWhat Is a Tubing Performance Curve (VLP)?
The outflow side of nodal analysis: the bottomhole pressure a well needs to lift each rate up the tubing.
Read → GlossaryWhat Is a Turboexpander (Gas Plant)?
How it expands gas to cryogenic cold to condense NGLs while driving a booster compressor.
Read → GlossaryWhat Is a Two-Phase Separator?
The simplest separator - gas-liquid split, vertical vs horizontal selection, and a single liquid dump - explained.
Read → GlossaryWhat is under-deposit corrosion (UDC)?
Hidden pitting beneath settled solids and scale that coupons and inhibitors miss, and how to control it.
Read → GlossaryVapor Recovery
Capturing hydrocarbon vapors from tanks instead of venting or flaring them, the equipment involved, and the emissions and value benefits.
Read → GlossaryHow do you verify a level bridle installation?
Confirm the taps bracket the span on the right nozzles, prove the chamber tracks the vessel, and understand the density offset before trimming.
Read → GlossaryHow do you verify a water-cut meter reading?
Confirm a representative sample, cross-check against a manual water cut, and rule out the range and emulsion traps that fool the meter.
Read → GlossaryHow do you verify a well-test allocation factor?
Trace the factor to its test, confirm the battery factors sum to measured sales, and reconcile theoretical against actual over time.
Read → GlossaryHow do you verify a well-test separator lineup?
Trace the well through the test header to the separator, confirm block and bypass positions, and prove the path by flow response.
Read → GlossaryHow do you verify a dyno sensor install?
Confirm the load cell is square in the load path, prove position at both stroke ends, and sanity-check the card shape.
Read → GlossaryHow do you verify an ESP gauge readout?
Confirm the panel has a live decode, the values are scaled right, and the SCADA faithfully mirrors the local panel.
Read → GlossaryHow do you verify gas-lift pressure sensors?
Check each against a test gauge, confirm the tags are not swapped, and prove each responds to a real well change.
Read → GlossaryHow do you verify an injection rate signal?
Confirm the rate is scaled and compensated, responds to the choke, and stays consistent with casing pressure.
Read → GlossaryHow do you verify a plunger arrival sensor?
Confirm it detects every real arrival, does not false-trigger between arrivals, and reports reliably to the controller.
Read → GlossaryHow do you verify separator level control during a well test?
Confirm the interface holds, dumps cycle cleanly through their meters, and no carryover or gas blowby is corrupting the phase split.
Read → GlossaryHow do you verify an SPM reading?
Time the unit by hand, confirm one clean count per stroke, and cross-check against card rate and drive speed.
Read → GlossaryWhat Is Volumetric vs Energy Allocation for Gas?
Allocating gas by raw volume versus by energy, and why energy is fairer for rich vs lean streams.
Read → GlossaryWhat Is a VRU?
Vapor recovery units - capturing tank flash gas instead of venting or flaring - explained, from compressor and scrubber to controls.
Read → GlossaryWhat Is VRU Recycle and Standby Sequencing?
How a VRU rides low or intermittent vapor with spillback and idle logic instead of short-cycling the compressor.
Read → GlossaryWhat Is VRU Suction Pressure Control?
The loop that holds tank suction at setpoint via recycle or speed so a VRU captures vapor without vacuum or short cycling.
Read → GlossaryWhat Is a VSD for ESP?
The surface drive that varies ESP frequency to match inflow - soft start, down-thrust, and gas handling explained.
Read → GlossaryWhat Is Water Cut?
The water fraction of a well's liquid stream - how it is measured, why it climbs over field life, and its SCADA role.
Read → GlossaryWhat is a Water Cut Meter?
The inline capacitance, microwave, or density-based instrument that measures the percent water in a stream.
Read → GlossaryWhat Is a Produced Water Degasser?
The vessel that strips gas out of produced water so it will not lock the injection pumps.
Read → GlossaryWhat Is a Water Dump Valve?
The level-controlled valve that discharges separated water from a vessel, in snap-acting or throttling form.
Read → GlossaryWater Recycling
Treating and reusing produced and flowback water for fracturing, the drivers, treatment steps, and the limits of oilfield reuse.
Read → GlossaryWhat Is a Well Annulus?
The A, B, and C spaces between well strings, and why annular pressure is a core integrity signal.
Read → GlossaryWhat Is a Well Swab Run?
A wireline swab run pulls fluid up the tubing to unload a dead or loaded well and kick it back into flow.
Read → GlossaryWhat Is a Well Test Procedure?
The routine to test one well: route it to the test separator, let it stabilize, and record oil, gas, and water rates.
Read → GlossaryWhat Is a Well-Test Allocation Factor?
How a periodic test separator sets each well's oil, gas, and water split until the next test.
Read → GlossaryWhat Is a Wellbore?
The drilled hole a well is built around - open vs cased hole, vertical vs horizontal, and how it produces.
Read → GlossaryWhat is wellbore storage in a pressure transient test?
The early-time effect where wellbore fluid, not the reservoir, dominates the pressure response and masks early data.
Read → GlossaryWhat Is a Wellhead?
The pressure-sealing surface assembly of an oil or gas well - components, function, and how it supports the Christmas tree - explained.
Read → GlossaryWhat Is a Wellhead ESD Pilot?
The high/low pressure pilot that trips the safety valve with no electronics when flow-line pressure strays.
Read → GlossaryWhat Is Wellhead Pressure?
The surface pressure that summarizes a well - flowing tubing vs casing vs shut-in pressure, and what trends reveal.
Read → GlossaryHow Do You Size RTU I/O for a Wellhead?
The practical I/O budget for a wellsite RTU - the analog and discrete points, plus 20 percent spare.
Read → GlossaryWhat Is a Wellhead SCADA Panel?
The field enclosure packaging RTU, radio, solar controller, battery, and I/O into one rated unit.
Read → GlossaryWhat Is Wireline?
Running tools down a live well on a cable - slickline vs electric line, logging, perforating, and intervention.
Read → GlossaryWhat Is a Workover?
Major well intervention to fix or improve a producer - pulling tubing, killing the well, and the workover rig.
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The system these terms describe.
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