R

R F Flange
SEE: Raised Face Flange.

Rabbit
Used to test the size of tubular goods.

Rack
A framework on or in which items such as pipe may be placed for containment.

Rack Pipe
To stand tubular goods in the derrick when coming out of the wellbore or to stack tubular goods on a pipe rack.

Racking Platform
A platform located at a distance above the working floor for laterally supporting the upper end of racked pipe.

Radar Unit
A device utilizing a method of detecting distant objects and determining their position, velocity, or other characteristics by analysis of very high frequency radio waves reflected from their surface.

Radial Pressure
Uniform external pressure acting only on the sides of a member.

Radiation Source
(1) The origin of radiation.(2) An X-ray tube or a radioisotope.

Radical
Two or more atoms behaving as a single chemical unit; i.e., as an atom; e.g., sulfate; phosphate; nitrate.

Radioactive Half Life
The time that it takes one-half of the parent atoms to decay radioactively.

Radioactive Tracer Log
A production log which measures radioactive tracer movements and, therefore, fluid movements in the immediate vicinity of the borehole.

Radioactivity
The spontaneous decay of certain atoms. An atom can decay by giving off: (1) An alpha particle (two neutrons and two protons).(2) A beta particle (one electron).(3) Gamma rays (energy).

Radioisotope
An unstable isotope of an element that disintegrates spontaneously, emitting radiation.

Radius Grind
Grinding performed to remove sharp edges and/or abrupt changes in the wall thickness around exploratory grinds or imperfections.

Radius Of Curvature Method
A borehole survey calculation method. The sets of angles are measured at the top and bottom of the course length to generate a space curve (representing the wellbore path) that has the shape of a spherical are passing through the measured angles at both the upper and lower ends of the measured course.

Rafted Ice
An ice sheet consisting of two or more layered ice sheets as a result of overriding.

Raised Face Flange
A type of flange having the gasket contact surface raised.

Ram
The closing and sealing component on a blowout preventer. Rams are of three types: blind, pipe, and shear. Pipe rams, when closed, have a configuration such that they seal around the pipe; shear rams cut through drill pipe and then form a seal. Blind rams seal on each other with no pipe in the wellbore.

Random Sampling
A prescribed number of units selected from a lot for inspection in such a manner that no unit is more likely to be selected than any other unit.

Range
(1) A single division, series or column of townships, each usually 6 miles square, extending parallel to and numbered east and west from a standard survey base meridian line.(2) The maximum value minus the minimum value.(3) The maximum ultrasonic path length that can be displayed.

Range Direction
Identifies the range direction (E or W) of a survey.

Range Number
The number of full or partial range divisions (approx. 6 miles wide) east or west of the reference principal meridian.

Ranking Scale
An absolute temperature scale that is used to determine standard gas volumes using a constant, such as degrees Fahrenheit plus 459.67.

Rapid Sand Filter
A relatively small filtering unit containing sand. The liquid movement through the sand bed is fairly rapid. The filter bed usually has to be cleaned often, by backwashing.

Rat Hole
A slanting hole located inside and near a corner of the derrick. It is cased with a large size length of casing and is about 25 feet deep. It forms a depository for the kelly so that the swivel, which connects to the upper end of the kelly can be conveniently adjusted and lubricated. It also provides an out of the way place for the kelly, swivel and kindred parts when drill pipe or casing is being run into the wellbore.

Rate Of Flow Calculations Remark
The calculations for determining well flow rates.

Rate Of Gas Flow Volume
The calculated volume of gas flow per specified time, typically 24 hours. Used as an intermediate value in further calculations to determine potentials or deliverabilities.

Rated Capacity
The rated load at specified radii as established by the manufacturer and are the maximum loads at those radii covered by the manufacturer's warranty.

Rated Setback Load
The maximum weight of tubular goods which can be supported by the substructure in the setback area.

Rated Static Rotary Load
The maximum weight being supported by the rotary table support beams.

Rated Working Pressure
The maximum internal pressure equipment is designed to contain and/or control.

Raw Gas
Gas as produced from a well before the extraction of liquefiable hydrocarbons.

Raw Make
Natural gas liquid stream that has not been separated into its component parts; e.g., ethane; propane; butane; gasoline.

Raypath Parameter
The quantity p = dt/dx = (1/V)sin i, where dt/dx is the reciprocal of apparent velocity, V is instantaneous velocity, and i is the angle a raypath makes with the vertical. For horizontal velocity layering, i = angle of incidence on a horizontal reflector, and p constant specifying a raypath.

Reactive Torque
Based on the physical property that action equals reaction, the torque reacting on the drillstem is that torque being generated at the point in question, such as at the bit.

Reactor
A vessel wherein two or more components react chemically under controlled conditions, often in the presence of a catalyst, to form one or more new components. Broadly speaking, may include catalytic crackers, regenerators and fractionators.

Readout
A device that visually indicates a condition or voltage or current. Typical devices used in inspection requirements are galvanometers and cathode ray tube (CRT).

Reamer
A downhole tool used to smooth the wall of a borehole, enlarge the borehhole, stabilize the drill bit, and straighten the borehole axis where kinks or doglegs are encountered.

Reaming
The operation of enlarging an existing borehole. Used to enlarge an undersized core hole so that the regular drilling bit can be run to bottom and drilling continued.

Rear End Radius
SEE: Tail Swing.

Reassignment Clause Flag
An indicator of whether or not a reassignment restriction is placed on a lease.

Reboiler
A refinery heater that reheats or reboils a part of a process stream drawn off a distilling column and then reintroduced to the column as a vapor.

Receiver Group
The set of geophones which collectively feed a single recording channel. Previously referred to as Detector Group.

Receiver Orientation
The orientation of a seismic receiver. The orientation is given as two angles. The first angle is the horizontal angle measured from a given reference direction (such as True North or the Inline Direction), measured positive in the counter clockwise direction. The second angle is the deviation from the horizontal, with vertically up being equivalent to 90 degrees and vertically down being equivalent to -90 degrees. Previously referred to as Detector Orientation.

Receiver Spacing
Distance between elements in a seismic spread. Previously referred to as Detector Spacing.

Receiving Waters
Rivers, lakes, oceans, or other bodies that receive treated or untreated waste waters.

Recess
(1) The counter bored section at the end of line pipe and oil country tubular goods couplings to facilitate stabbing the thread.(2) An enlargement in conduit bore, generally concentric with the bore.

Reciprocating
The propelling of fluids by the use of a piston moving in a to-and-fro motion through a cylinder.

Reclaimed
Processed for reuse.

Reclaimer
A vessel in which undersirable heavy ends or impurities are removed from a stream by vaporizing material within a desired boiling range.

Recompletion Date
The date that recompletion operations ended and production resumed.

Recompletion Project
Operations involving any of the following: (1) Deepening from one zone to another zone.(2) Completing well in an additional zone.(3) Plugging back from one zone to another zone.(4) Sidetracking to purposely change the location of the bottom of the well, but not including sidetracking for the sole purpose of bypassing obstructions in the borehole.(5) Conversion of a service well to an oil or gas well in a different zone.(6) Conversion of an oil or gas well to a service well in a different zon

Reconcentrator
A low pressure heated vessel designed to boil impurities out of a liquid, thereby reconcentrating the liquid.

Record
SEE: Seismic Acquisition Record.

Record Type Code
An indicator of whether a tape transmitted report record is a district (D) record or a report (R) record.

Recording Book
The recording book identifies the book where the lease is recorded in the county or recording district records.

Recording District Code
Indicates the recording location is a district rather than a county. The recording is made in a state/province authorized recording district; e.g., Bolivar cty-dist-Rosedale; Bolivar cty-dist 2-Cleveland; Carroll cty-dist 1-Carrollton.

Recording File Number
Shows the file number assigned by the recording county or district to a legal instrument.

Recording Gauge
A device that provides a chronological record of gauge readings.

Recording Instrument
A device used to capture signals from seismic receivers during a seismic event.

Recording Location
Shows the state and county or recording district in which a legal instrument is recorded.

Recording Location County
The county or parish where a lease instrument is recorded.

Recording Location Date
The date that a mineral lease, amendment, or correction was recorded in the Recording Book.

Recording Location State
The state in which a legal instrument is recorded, in combination with the county or recording district, shows where the instrument is recorded.

Recording Memo
Any recording information which does not fit into the commonly used book page format; e.g., the Louisiana register number.

Recording Page
Shows the page or microfilm reel number on which a legal instrument is recorded. Also referred to as: Reel Number.

Recording Type
Specifies the type of recording; e.g., amendments; corrections; original; releases.

Recoverable Usage
The injection of oil into a formation to stimulate production. This oil may be recovered in later production.

Recovered Gas Flow Rate During Test
The estimated average flow rate of gas recovered during the entire test; e.g., drillstem test; formation; reservoir limits.

Recovered Gas Lift Gas
Gas lift gas which has returned to the wellbore origin and is re-produced. Also referred to as: Spent gas lift gas.

Recovered Water Flow Rate During Test
The estimated average flow rate of water recovered during the entire test; e.g., drillstem test; formation; reservoir limits.

Recovery Factor
Percentage of the total hydrocarbon in a reservoir that ultimately can be withdrawn by primary or enhanced techniques.

Recovery Overpayment Federal Tax Amount
The portion of a lease Federal tax associated with an overpayment that goes with the current month's recovery.

Recovery Overpayment Gross Amount
The portion of a lease gross value associated with an overpayment that goes with the current month's recovery.

Recovery Overpayment State Tax Amount
The portion of a lease state tax associated with an overpayment that goes with the current month's recovery.

Recovery Overpayment Volume
The portion of a lease volume associated with an overpayment that goes with the current month's recovery.

Recovery Project Identifier
An indicator of a grouping of wells in an enhanced recovery project.

Recovery Project Name
The name of an enhanced recovery project.

Recovery Start Date
The year, month and day that the recovery of an overpayment is to begin.

Recovery Volume
The total volume of hydrocarbons that has been or is anticipated to be produced from a well or field, or the fluids obtained from a drillstem test.

Rectifier
A device for converting alternating current into direct current. Used to reduce corrosive action caused by reversing electric current.

Recycle
The return of part of a stream to a location for additional processing in order to increase recovery of the desired components.

Recycling
The process by which materials pass through a cycle and undergo change or treatment, thus permitting their reclamation in some form to further use.

Redelivery
The delivery of natural gas by a pipeline to a shipper or for a shipper's account.

Redress
Replacement of items as defined in the Manufacturer's Operating Manual. Redress may be performed on or away from well site. Each replacement item should be a qualified part.

Reduced Opening Valve
A valve which has a reduced opening through its closure mechanism.

Reducer
That which narrows down, lowers, or drops;e.g., reducing tubular size, speed of an engine or motor, gear, etc.

Reel System
A circular drum and assorted mechanical equipment used to spool wireline.

Reeving
A rope system where the rope travels around drums and sheaves.

Reference Block
A block or series of blocks of material containing artificial or actual discontinuities of one or more reflecting areas at one or more distances from the test surface, which are used for reference in calibrating instruments and in defining the size and distance of defective areas in materials.

Reference Document Line Number
The line number of the original reference document.

Reference Document Number
The number of the original document to which the invoice refers.

Reference Document Receipt Date
The date the original reference document is received.

Reference Document Type
The original document type to which the invoice refers.

Reference Electrode
A standard cell of known voltage used for making voltage measurements of a corrosion cell. Calomel and copper sulfate are common reference electrodes.

Reference Magnet
Magnets inset in the wall of the nonmagnetic drill collar. Used to indicate a position of the deflecting tool with respect to magnetic north. A picture of a magnetic needle compass at the magnets is imposed on the picture of the magnetic north compass.

Reference Set
A collection of information referred to by another attribute. Example is a collection of map projection information and affine transformation parameters to define the local map and absolute location for a point.

Reference Standard
A pipe containing machined notches or natural defects used as a base for comparison or for inspection equipment standardization.

Refiner Name
The name of the entity who processes crude oil and condensate.

Refitting Cost
Costs incurred from time to time to move a drilling unit to a suitable port, carry out repairs, maintenance, and modifications on the drilling unit including inspection costs and obtaining the necessary certifications by the relevant government authorities.

Reflection
The process in which a portion of the wave energy does not transmit across a surface, but is returned from the surface.

Reflection Angle
The angle defined by the direction of the reflected wave and the normal to the interface at the point of incidence. The angle of reflection is equal to the angle of incidence.

Reflector
Any material variation returning wave energy.

Reflux
The liquid condensed from overhead vapors that is returned to the top tray of a fractionator.

Reformer
A vessel that causes oil or gas cracking (a process in which relatively heavy hydrocarbons are broken up by heat into lighter products).

Refraction
The bending of transmitted rays in wave propagation caused by a change in the properties of the transmitting medium. The bending may occur at an abrupt change of properties (a discontinuity) or gradually if the properties change gradually.

Refraction Angle
The angle between the refracted rays and the normal to the refracting surface.

Refraction Statics
SEE: Static Correction.

Refractive Index
The ratio of the velocity of a wave in one medium to the velocity of the wave in a second medium is the refractive index of the second medium with respect to the first. It is a measure of the amount a wave will be refracted when it enters the second medium after leaving the first

Refrozen Lead
Lead in which ice has grown, but remains relatively smooth. Thickness can vary from a few inches to several feet.

Refund Provision Flag
An indicator of whether the gas purchaser must currently disburse questionable amounts.

Regenerator
A vessel in which a diluted, spent, or contaminated catalyst or stream is brought toward its original condition.

Regenerator Unit
A unit to strip the gas components which are absorbed in the absorber/contactor from the absorbent liquid, molecular sieve, or other absorbants.

Regular Minimum Payable Amount
The minimum amount of money allowed to be paid by a check prepared by the regular check writing process. This amount is controlled by pay code.

Regular Opening Valve
A valve which may have a reduced opening, either round or oblong, through the closure member. The area of this opening is usually from 50 to 100 % of the pipe cross sectional flow area.

Regulation
A rule or policy defined by a regulatory agency which obligates a business associate to specific procedures and reporting.

Regulator
(1) A piece of equipment used to control a phase of a process or operation. (2) A device that automatically controls the flow, pressure, or temperature of a liquid or gas through a line.

Regulatory

Regulatory Agency
A geopolitical entity that is empowered to create, administer, and/or enforce regulations within a specific jurisdiction.

Regulatory Agency Name
The name of the state or Federal regulatory agency which receives reports or statements.

Regulatory Agency Representative Name
The name of an official or authorizing person representing a state or federal regulatory agency.

Regulatory Area
An area of interest defined by a regulatory agency for the purposes of implementing a regulation or rule.

Regulatory District Name
The name assigned to a state or Federal regulated district.

Regulatory District Number
The number assigned to a state or Federal regulated district by the appropriate regulatory agency.

Regulatory Field
A field that has been defined by a regulatory agency.

Regulatory Field Code
An indicator of a surface area containing a subsurface accumulation of a natural resource. These indicatorss are unique within the state and are assigned by the regulatory agency. In the states of Illinois, New Mexico and Oklahoma, it is synonymous with pool number.

Regulatory Field Name
The name assigned by the regulatory agency or state to the field; an assigned name that describes a producing oil & gas field.

Regulatory Guideline Identifier
The identifier for the regulation or order issued by a regulatory agency.

Regulatory Lease
A boundary, surface or subsurface, established by a regulatory agency for the right to explore for and produce hydrocarbons. Parameters involved in defining a lease: product, spacing orders, ownership, etc.

Regulatory Lease Name
A name assigned to a lease by the responsible regulatory agency.

Regulatory Lease Number
A lease number assigned by a regulatory agency to a legal document for the right to explore for and produce hydrocarbons.

Regulatory Lease Well Name
The name assigned to a well by a regulatory agency.

Regulatory Property Number
A number assigned by the regulatory agency to a property.

Regulatory Purchaser Name
The standard name for a particular purchaser assigned by a specific regulatory agency.

Regulatory Renewal Type
Identifies contracts as: Original; Replacement renewed prior to 11-08-78; Rollover; Renewed on or after 11-08-78.

Regulatory Report Id Code
An agency identifier for a regulatory report.

Regulatory Report Identifier
The agency identifier for a regulatory report.

Regulatory Reservoir
A reservoir defined by a regulatory agency.

Regulatory Tax And Fee Due Amount
The amount of regulatory tax and fee due.

Reheater
A device used to reheat a stream.

Reinjection Volume
The volume of gas reinjected to the reservoir.

Reject
A control for minimizing or eliminating low amplitude signals (electrical or material noise) so that larger signals are emphasized. Also referred to as: Suppression.

Reject Level
The value that is established as a baseline test signal, and is used to determine whether specimens that are above or below the baseline may be rejectable, or otherwise distinguished from the remaining specimens.

Reject Opening
SEE: Underflow Opening.

Related Contract Number
Identifies a specific contract that is associated to the host contract.

Related Contract Type
This indicator shows the relationship between two contracts; i.e., superceded contract; related over/short contract for sales contract with split delivery.

Relative Age
The geologic age of a fossil organism, rock, geologic feature, or event, defined relative to other organisms, rocks, features, or events rather than in terms of years.

Relative Bearing
The clockwise azimuthal angle from the upper side of the survey tool to the reference electrode, measured looking down the wellbore.

Relative Density
The ratio of the mass of a given volume of a substance to the mass of a like volume of a standard substance; e.g., water; air.

Relative Permeability
A measure of the ability of two or more fluids to flow through a rock sample when the sample is saturated with more than one fluid; e.g., water; gas; oil.

Relay
An electromagnetic device for remote or automatic control actuated by variation in conditions of an electric circuit and operating in turn other such devices (such as switches) in the same or different circuit.

Release Gas
Gas previously contracted and dedicated between producers/brokers and a transporter company which, through mutual agreement between the parties, was thereafter released from contract and ultimately made available for purchase by third parties.

Relevant Indication
An indication resulting from a discontinuity in the pipe.

Relief Valve
A valve that opens when the pressure reaches a predetermined value.

Relief Well
A wellbore segment drilled to intersect an existing wellbore that is out of control.

Remaining Producing Wells Count
The number of wells remaining on the property or facility that are producing or capable of producing.

Remaining Royalty Producing Wells Count
The number of wells remaining on the royalty account that are producing or capable of producing.

Remanent Magnetization
The component of the earth's magnetization that has a fixed direction relative to the rock and is independent of moderate applied magnetic fields; i.e., the earth's magnetic field.

Remanufacture
Any activity involving disassembly, reassembly and testing of equipment or any item thereof, with or without the replacement of qualified parts where machining, welding, heat treating or other manufacturing operation is employed.

Remark Type Code
An indicator of the type of remark associated with a specific entry.

Remedial Sidetrack
The basic bypassing of obstructions in the borehole, such as stuck pipe, while drilling a well and returning to the original objective.

Remnant Permafrost
Permafrost existing in a soil prior to construction and installation activities.

Remote Control Panel
A panel containing a series of controls that will operate the valves on the control manifold from a remote point.

Remote Control Station
A centrally located station containing equipment to control and regulate operations in one or more fields.

Remote Reading Gauge
An instrument capable of providing indications of pressure, vacuum, voltage, etc., at a point remote from the place that such indications are actually taken.

Remote Terminal Unit
An electronic equipment package used to control an individual location connected to a supervisory unit.

Rent Payor Flag
An indicator that the party who completed the form will be responsible for payment of advanced rentals.

Rental
Money or other property given to maintain a mineral lease in the absence of drilling or mining operations or production of minerals.

Rental Amount Type
Indicates whether the payment was made on a per acre or lease basis.

Rental Check Number
The identifier of a lease rental check which includes the bank account number followed by a sequential check number.

Rental Frequency
Frequency of mineral lease rental payments; e.g., annual; semiannual; quarterly; monthly.

Rental Payment Agent
Party charged with the rental paying responsibility; e.g., we pay; partner pays.

Rental Period
The calendar period that covers the contractual rental payment agreeement.

Repair Grind
A grind made to remove a questionable imperfection and make the product comply with the appropriate specification.

Repair Of Oil Or Gas Or Service Well
SEE: Workover.

Repeat Formation Test
SEE: Drillstem Test; Production Test.

Repeated Section
A portion of the geologic column encountered more than once during drilling or surface transect. Repeated sections are encountered across reverse or thrust faults, but they can also be encountered in severly deformed rocks without faults or across normal faults in such rocks.

Repetition Rate
The rate at which the individual pulses of acoustic energy are generated. Also referred to as Pulse Repetition Rate.

Replacement Velocity
The velocity used in static corrections and wave equation datuming to compensate for low velocity near surface materials.

Reply Due Date
The date the originator has requested response from the other parties.

Report Attachment Code
An indicator of which attachments accompany a report. Options include log section, reservoir structure map, soil sample analysis, etc.

Report Attachment File Format Type Code
The format type of an electronic file submitted as an attachment to a report. E.g., ASCII, LIS, LAS, GIFF, etc.

Report Attachment File Name
The name given to an electronic file attached to a report.

Report Date
The month and year of the report.

Report Filing Code
An indicator of whether reported data is original, corrected, re-submission, proposed, information copy, etc.

Report Number
The number used to identify a report as an original or the sequential number of the amendment.

Report Period Date
The calendar period for which the report is submitted.

Report Period End Date
The ending date of the reported period.

Report Period Start Date
The starting date of the reported period.

Report Preparer Name
The name of the individual filing a report .

Report Preparer Title
The title of the individual filing a report .

Report Remark
A narrative of pertinent report information.

Report Submission Date
The date the return was submitted.

Report Total Production Volume
The total production volume as reported.

Reporter Identifier
An identifier of the person or company filing a report with a regulatory agency.

Repressuring
A program of increasing or maintaining reservoir pressure by injecting gas or fluids into one or more wells with completions in the reservoir to increase oil producing rate and ultimate oil recovery.

Requested Maximum Production Rate
The maximum production rate (MPR) applied for by the operator.

Rerun
(1) To reprocess an off specification material to produce an acceptable product.(2) A second run of an electric log or drillstem test.

Reserve Calculation Method Code
An indicator to describe the method of calculating reserves.

Reserved Production Payment
A production payment in which the owner of the royalty or working interest sells the residual interest to a second party but reserves a production payment, which he may retain or sell simultaneously to a third party.

Reserves
Reserves are the estimated volumes of crude oil, condensate, natural gas, natural gas liquids, and associated substances anticipated to be commercially recoverable from known accumulations from a given date forward, under existing economic conditions, by established operating practices, and under current government regulations. Reserves estimates are based on interpretations of geologic and/or engineering data available at the time of the estimate. Reserves do not include volumes of crude oil, condensate

Reservoir
A volume of reservoir rock containing a contiguous natural accumulation of producible fluids and characterized by a single pressure system.

Reservoir Acre Feet Volume
An acre of hydrocarbon reservoir one foot thick.

Reservoir Boi Calculation Code
Indicates whether the initial oil bubble point value (Boi) is manually calculated or internally calculated.

Reservoir Bulk Volume
The total volume of rock and included fluids contained in a reservoir segment interval.

Reservoir Current Reservoir Pressure Date
The date the current reservoir pressure is determined.

Reservoir Current Static Pressure
The current static pressure at reservoir datum depth.

Reservoir Datum Depth
The subsea depth to the average depth of the reservoir.

Reservoir Drive Mechanism
The natural drive mechanism of a reservoir for the recovery of reservoir fluids; e.g., solution gas drive; dissolved gas drive; water drive; depletion drive; gas cap drive; gravity drainage; combination drive.

Reservoir Drive Mechanism Code
An indicator of the mechanism that provides the primary source of reservoir energy.

Reservoir Energy
The energy inherent in a reservoir which forces the reservoir fluids to the borehole.

Reservoir Fluid
Natural fluids within a reservoir rock. The reservoir fluid may be either a liquid or a gas and may contain certain nonhydrocarbon compounds. The nonhydrocarbon compounds which are of sampling importance are nitrogen, carbon dioxide, hydrogen sulfide, helium, and water (usually brine).

Reservoir Fluids Contact
SEE: Oil Water Contact; Gas Oil Contact; Gas Water Contact.

Reservoir Gas Acreage
The areal extent of the gas portion of a reservoir.

Reservoir Gas Recoverable Reserves Volume
The quantity of gas that is expected to be recovered from the reservoir.

Reservoir Initial Gas Reserves Volume
The original quantity of gas that has accumulated in the reservoir.

Reservoir Interval
The vertical declination of a reservoir rock.

Reservoir Name
The name given to an oil or gas reservoir.

Reservoir Oil Acreage
The areal extent of the oil portion of a reservoir.

Reservoir Pay Thickness
The vertical length of the pay zone.

Reservoir Pressure Measurement
The pressure measurement recorded for the fluids present in a reservoir.

Reservoir Pseudoreduced Pressure
The pseudoreduced reservoir pressure (Pr).

Reservoir Pseudoreduced Temperature
The ratio of the reservoir temperature (T) to the critical temperature (Tc) by the formula (Tr=T/Tc). This ratio is used to calculate the gas compressibility factor (Z factor) according to the Law of Corresponding States. Pseudo refers to the fact that the gas involved is a mixture of gases and not a pure compound. All temperatures are expressed in degrees Absolute.

Reservoir Pseudoreduced Temperature Calc Code
Indicates whether the pseudoreduced temperature (Tr) value is manually calculated or internally calculated.

Reservoir Remaining Gas Reserves To Production Ratio The Number Obtained By Dividing The Remaining Gas Reserves In A Reservoir By The Gas Produced From The Same Reservoir In The Last 12 Months.

Reservoir Remaining Gas Reserves Volume
The quantity of gas that remains to be produced from the total reservoir.

Reservoir Remaining Oil Reserves To Production Ratio The Remaining Liquid Hydrocarbon Reserves Divided By The Liquid Hydrocarbon Produced From The Same Reservoir In The Previous 12 Months.

Reservoir Remaining Oil Reserves Volume
The liquid hydrocarbons that remain in a reservoir which can be economically produced.

Reservoir Rock
Porous and permeable rock that potentially can accumulate producible fluids.

Reservoir Seal
The confining barrier or restriction to migration of pore fluids through the reservoir rock of a reservoir.

Reservoir Segment
An areally differentiated portion of a reservior. A reservoir segment may contain one or more vertically differentiated reservoir zones.

Reservoir Static Pressure Date
The year and month of the most recent pressure test for a specific reservoir.

Reservoir Temperature Measurement
The temperature measurement recorded for the reservoir rock and/or its fluids.

Reservoir Volume Factor
(1) Factor used for converting surface hydrocarbon volumes to reservoir volumes.(2) The inverse of Formation Volume Factor.

Reset Point
A means for shifting the proportional band on a control instrument with respect to its control point.

Reshoot
To reoccupy a seismic source location, and set off another shot.

Residual
In refining: (1) The concentration of chemicals which form in a boiler or other treater water system.(2) Oils that are leftovers in various refining processes.(3) Heavy black oils used in ships' boilers and in heating plants. In measurement: (1) The difference between a measurement (or estimation) of a quantity and the expected value.

Residual Field
The remaining magnetic field retained by ferromagnetic materials after they have been exposed to a magnetic force.

Residual Method
Inspection utilizing the residual magnetic field remaining in the pipe after magnetization for obtaining indications.

Residual Oil
In laboratory reservoir fluid analysis, the liquid remaining at atmospheric pressure following the differential liberation of gas at reservoir temperature.

Residual Percentage
The percent of product remaining after a test.

Residual Statics
Static corrections applied to cause a better coherency among seismic events within a gather. The mean shift within the gather is zero. Residual statics is generally required because the near surface model is not known in enough detail to create this coherency.

Residual Stress
The stress that remains in an unloaded member after it has been formed and installed in a structure. Some typical causes are forming, welding and corrections for misalignment during installation in the structure. The misalignment stresses are not accounted for by the plasticity reduction factor n.

Residual Time
Difference between the observed time and the regional time.

Residue
The remaining fluid after the removal of certain elements and compounds in a fractionator, separator, tank, plant process, etc.

Residue Allocation Charge Type
Identifies the type of charge deducted from the lease value determined by amount of residue allocated to a lease.

Residue Gas
Gas from a processing unit after extraction of liquids. Also referred to as: Tail Gas.

Residue Gas Available For Sale Volume
Plant residue gas which is not used as plant fuel or returned to the producer for use in lease operations.

Residue Gas Minimum Percentage
The minimum percentage of residue gas which must be available for sales after processing under a gas processing agreement.

Residue Gas Price Per Unit Amount
The value per unit of measure of residue gas.

Residue Gas Returned Nonexempt Volume
The residue returned to lease in excess of allowances.

Residue Gas Returned Volume
Plant residue gas delivered back to the producer for use in lease operations.

Residue Percentage
The percentage calculated by dividing the volume of the residue by the initial sample volume.

Residue Pooling
Provision in many casinghead gas purchase contracts providing that all of the seller's properties covered by the contract will be treated as a single property in determining whether producer has taken more residue gas for use in operations than the quantity to which he is entitled

Residue Purchaser Name
The name whichIdentifies the residue purchaser for a gathering system/plant.

Resin
Semisolid or solid complex, amorphous mixture of organic compounds having no definite melting point nor tendency to crystalize. Resins may be a component of compound materials that can be added to drilling fluids to impart special properties to the system, wall cake, etc.

Resistivity
The electrical resistance offered to the passage of a current, expressed in ohm-meters; the reciprocal of conductivity. Fresh water drilling fluids are usually characterized by high resistivity; salt water drilling fluids by a low resistivity.

Resistivity Log
Any of several types of well logs on which some aspect of rock resistivity has been recorded.

Resistivity Measurement Date
The date that resistivity measurements were taken.

Resistivity Meter
An instrument for measuring the resistivity of drilling fluids and its cakes.

Resolution
(1) The ability of ultrasonic equipment to give simultaneous, separate indications from discontinuities having nearly the same range and lateral position with respect to the beam axis.(2) The ability to separate two features that are very close together.

Response Date
The date that response is transmitted to the originator, generated by an electronic data interchange (EDI) transmission.

Response Factor
The relationship between the amount of a component in a sample and its resulting electrical response on a chromatogram.

Restricted Area Sealing Means
A seal which encloses a pressure containment area smaller than the adjacent API ring gasket.

Retention Percentage
The ratio of recovery to extraction for a given component, expressed as a percentage.

Retention Time
The time any given particle of material is actually on the screening surface.

Retrievable
Ordinarily has reference to special subsurface equipment which , after use, can be released and recovered from the wellbore.

Retrograde Condensation
Condensation of hydrocarbons from a gaseous state to liquids as a result of reduction of pressure. Begins as pressure in a reservoir drops to about 3,600 pounds per square inch and reaches maximum at reservoir pressure of about 1,600 psi.

Return On Investment
The ratio of: (1) the ultimate value of the reserves attributable to a well less the drilling investment, taxes, operating costs, and other needed investments anticipated during the life of a well, to (2) the drilling and other investments anticipated during the life of the well. Frequently cited as ROI.

Revenue Source Code
An assigned indicator denoting the type of agreement where by wells are placed and produced; examples are state spacing requirements and unit operating agreements.

Reverse Circulation
The direction of drilling fluid circulation in which the circulating liquid returns to the surface through the drill pipe after being pumped down the annular space. Typically done to remove potentially combustible material from the drillstring after drillstem testing.

Reverse Fault
A dip slip fault in which the hanging wall moves up and over the footwall.

Reversed Cone Offset
SEE: Negatively Skewed Bit.

Reversionary Option Exercised Code
An indicator of whether or not the company has elected to exercise its option to convert to a working interest or to escalate its overriding royalty interest (ORI).

Reversionary Option Exercised Date
The company has the option to convert to a working interest or to escalate its overriding royalty interest (ORI). This is the actual date that the company elects to convert to a working interest or to escalate its ORI.

Revolving Upperstructure
The rotating upper frame structure and the operating machinery mounted thereon.

Reworking A Well
SEE: Workover.

Reynolds Number
A dimensionless number that occurs in the theory of fluid dynamics. The diameter, velocity, density, and viscosity (consistent units) for a fluid flowing through a cylindrical conductor are related as follows: Re = (diameter) (velocity) (density)/(viscosity). The number is important in fluid hydraulics calculations for determining the type of fluid flow; i.e., whether laminar or turbulent. The transitional range occurs approximately from 2,000 to 3,000; below 2,000 the flow is laminar, above 3,000 the

Rheology
The study of the deformation and flow of matter.

Rheostat
A resistor for regulating a current by means of variable resistances.

Rhp
SEE: Rotary Horsepower.

Rich Amine
Monoethanolamine (MEA) which contains all the acid gas extracted in the contactor.

Rich Gas
SEE: Wet Gas.

Rich Oil
Absorption oil which contains all materials extracted in the absorber.

Ridge Keel
The portion of an ice ridge that extends below the water line. Can be partially consolidated in first year ridges but the depth of consolidation is variable.

Ridge Sail
The portion of a ridge that extends above sea level. In early season the sail of a first year ridge is generally composed of loosely stacked blocks. In multiyear ridges, the sail becomes eroded or worn smooth due to summer melting and ultimate refreezing, and is generally composed of almost solid, freshwater ice with numerous air pockets.

Rig
The derrick, drawworks and attendant surface equipment of a drilling or workover unit; e.g., rotary, cable tool, wire line spudder, auger type spudder, service unit.

Rig Anchor
The anchors installed around a floating rig for stabilization.

Rig Arrival Date
The date the rig is moved onto the well site.

Rig Catwalk
SEE: Catwalk.

Rig Contractor Name
The name of the contractor operating the drilling rig.

Rig Fluid System
A network of tanks, pipework, pumps, and solids control equipment that is capable of building, maintaining, delivering, and handling the return of sufficient fluid to support drilling and completion activities.

Rig Height
The height of the drilling rig floor above ground or water level.

Rig Moved On Well Location Date
SEE: Rig Arrival Date.

Rig Name
The name of a drilling rig.

Rig Number
The rig number assigned by the rig contractor or regulatory agency.

Rig Power System
A package of equipment which is designed to provide electrical, hydraulic, or pneumatic power.

Rig Released Date
The date that any rig is released from operations as specified in the contract and can be moved from the well site.

Rig Rotating System
A package of equipment which is designed to provide rotational power to a drillstring. Two distinct mechanisms are in common use: 1) the rotary table, which is set into the drill floor with power being transmitted to the drillstring via a bushing and a profiled kelly; 2) the top drive, a large motor and gear box assembly mounted in the derrick directly above the rotary table which is free to travel vertically as required.

Rig Type
The type of rig installation; e.g., land; barge; submersible; platform; jackup; drillship; semisubmersible; artificial island.

Rigging Up
The on site erection and connection of the rig components in preparation for drilling or well servicing operations.

Right Hand Thread
A thread that winds in a clockwise receding direction when viewed axially.

Right Lateral Strike Slip Fault
A strike slip fault in which the opposite fault block has moved relatively to the right, with the predominant motion being strike slip. Also referred to as: dextral fault.

Right Longitude Of Area
The easternmost longitude of an area.

Rights Of Way Permit Number
The number assigned by a regulatory agency to identify the permit granting permission to construct facilities on public surface.

Rigidity
(1) The stiffness or flexibility characteristics of a bottomhole assembly or an element thereof.(2) The property of a material to resist applied stress that would tend to distort it.

Rik
SEE: Royalty-In-Kind.

Ring Gear
SEE: Swing Gear. Also referred to as: Bull Gear.

Ring Stiffened
A member with circumferential stiffeners.

Ringing
SEE: Springing.

Ringing Time
The time that the mechanical vibrations of a crystal continue after the electrical pulse has stopped.

Riparian Right
Rights of a land owner to the water on or bordering his property, including the right to prevent diversion or misuse of upstream water.

Riser
A pipe through which fluid travels upward.

Riser Box
The female coupling member of a riser assembly.

Riser Handling Equipment
Usually consists of a riser handling sub and a riser spider. The riser sub latches on to the end of the riser joint permitting it to be connected to the surface lifting device. The riser spider is used to support the riser string, during deployment/retrieval, as a joint is being made or broken. Also referred to as: Riser Running Equipment.

Riser Joint
A section of riser pipe having ends fitted with a box and a pin.

Riser Pin
The male coupling member of a riser assembly.

Riser Pipe
The basic pipe from which riser joints are fabricated.

Riser Spacer Frame
A purpose designed frame to maintain lateral separation among risers.

Riser Spider
A device used to support the riser string as a joint is being made or broken during riser deployment/retrieval operations.

Riser Spoiler
Used in areas where high velocity currents are encountered to preclude vortex induced riser vibration. Various types of spoilers have been effective in reducing these vibrations; however, they frequently result in increase in drag forces.

Riser Sub
A device which latches on to the end of the riser joint permitting it to be connected to the surface lifting device.

Rock
(1) Aggregate of one or more minerals; e.g., granite; shale; marble.(2) A body of undifferentiated mineral matter; e.g., obsidian.(3) Solid organic matter; e.g., coal.

Rock A Well
To alternately bleed pressure from casing, then tubing, of a dead well, in an effort to start to flow.

Rock Anisotropy
Refers to the differences in physical properties of rocks as related to the directional characteristics.

Rock Pressure
SEE: Reservoir Pressure.

Rock Stratigraphy
SEE: Lithostratigraphy.

Rock Type
SEE: Igneous Rock; Metamorphic Rock; Sedimentary Rock.

Rockwell Hardness
The resistance of a material to indentation with a small diamond point or a 1/16 inch diameter ball. This correlates directly with strength.

Rod
SEE: Sucker Rod.

Rod Board
A platform located at a distance above the working derrick floor for supporting sucker rods.

Rod Guide
An attachment to sucker rods which serves to prevent them from rubbing on the sides of the tubing.

Rod Pumping Unit
A piece of equipment used to reciprocate a rod pump installed on a well in order to produce fluid.

Roi
SEE: Return on Investment.

Roll
Platform rotation about the plant north-south axis.

Roll Mark
A term applied to surface imperfections caused by improper roll alignment or roll surface damage. Such imperfections may be periodic or continuous.

Roll Mean Period
The average time elapsing between successive occurrences of roll, measured over the interval.

Roll Off
SEE: Filter Response.

Roll Off Angle
A measure of the tendency of a drill bit to spin off the face of a whipstock. The roll off angle affects the azimuth but not the inclination of the deviation and is used to correct the whipstock orientation before the well is kicked in.

Roll P P Max
The average of the highest one-tenth observations of the roll of the vessel measured over the interval.

Roll P P Sig
The average of the highest one-third observations of roll of the vessel measured over the interval.

Rolled In Scale
A surface imperfection caused by scale, formed during a previous heating, which has not been eliminated prior to surface rolling. Also referred to as: Scab.

Rolled In Slug
A foreign metallic body rolled into the metal surface, usually not fused.

Roller Path
The surface upon which the rollers that support the revolving upperstructure bear. It may accommodate either cone rollers or live rollers.

Rolling Cutter Reamer
The outermost radius provided by cutting roller members.

Rolling Element
The balls or rollers contained between the rings of the swing circle bearing.

Rollover Contract
(1) Contract that expires and is renegotiated.(2) Under the NGPA, any contract that is entered into on or after November 9, 1978 for the first sale of natural gas that was previously subject to an existing contract which expired at the end of a fixed term.

Root
The bottom of a thread.

Root Truncation
The distance between the sharp root (root apex) and the finished root.

Rope
Length of fibrous strands (at least one inch in circumference) woven, twisted or braided together.

Rope Discharge
The characteristic underflow of a hydrocyclone so viscous and overloaded with separable solids that not all the solids reporting to the underflow can crowd through the underflow opening. Also referred to as: Rope.

Rope Falls
Block and tackle arrangements to assist in wireline operation equipment placement.

Rose Diagram
A polar plot or diagram in which radial distance indicates the relative frequency of an observation at a certain azimuth.

Rotary
A device that moves fluids by use of an impeller rotating around its own axis.

Rotary Bit
A cutting device at the end of a drill pipe rotated by an engine powered table on the rig floor. Rotary bits are of many shapes and designs, from the simple fishtail bits to the cones or rollers which revolve as the tool turns.

Rotary Bushing
A metal lining that fits into the rotary table opening to reduce its size for special purposes; e.g., to fit the slips; to fit the kelly bushing. Also referred to as: Master Bushing.

Rotary Drilling
The method of drilling that depends on the rotation of a column of drill pipe to the bottom of which is attached a drill bit. A drilling fluid is circulated to remove the cuttings.

Rotary Horsepower
The horsepower required to rotate the drillstring and the bit. Rotary Horsepower= Torque (ft-lb) x RPM/5,250.

Rotary Hose
On a drilling rig, the hose that conducts the drilling fluid from the mud pump and standpipe up to the swivel and kelly. Also referred to as: Mud Hose.

Rotating Head
A rotating pressure sealing device used in drilling operations utilizing air, gas, foam, or any other drilling fluid whose hydrostatic pressure is less than the shut in formation pressure.

Rotating System
SEE: Rig Rotating System.

Rotation Axis
The vertical axis around which the rotation takes place.

Rotation Resistant Rope
A wire rope consisting of an inner layer of strand laid in one direction covered by a layer of strand laid in the opposite direction. This has the effect of counteracting torque by reducing the tendency of the finished rope to rotate.

Rotator
A device installed on polished rods to turn sucker rods if paraffin scrapers are attached.

Rotor Diameter
The diameter of a circle by the rotor blades while rotating. Commonly abbreviated as: RD.

Roughneck
A driller's helper and general all around worker on a drilling rig.

Round Trip
Pulling the drill pipe, usually for changing the drill bit or tubing and rerunning to the wellbore bottomhole.

Roundness
Indicates the degree of abrasion of a clastic particle as shown by the sharpness of its edges and corners; e.g., very angular; rounded.

Roustabout
An employee who does general oil field work related to the production, transportation, treating, and storing of oil and gas.

Royalty
The share of the production or proceeds therefrom reserved to the lessor under the terms of a mineral lease. Normally, royalty interests are free of all costs of production (as distinguished from costs of marketing) except production taxes.

Royalty Acreage
Includes fee lands and mineral interests (leased and unleased), royalties, overriding royalties, oil payments out of production, and any other interests in acreage in which the company has a working interest.

Royalty Clause Type
Indicates whether the oil & gas lease royalty clause is a provision or deduction.

Royalty Disbursement Flag
An indicator of whether or not the company is required to disburse payment to royalty owners.

Royalty Due Amount
The amount of royalties due.

Royalty Interest Percentage
The share of the minerals reserved, free of expense, by a mineral interest owner when leasing the property to another party.

Royalty Owner Percentage
The share of royalty reserved for the mineral interst owner.

Royalty Production
The share of total lease production which is reserved for the mineral interest or fee owner.

Royalty Provision Type
Identifies the type of standard royalty provision clauses contained in mineral leases; e.g., market value; percent on proceeds; special type of an oil and gas lease; gas royalty agreement; government; state; Indian; right for the free use of gas.

Royalty Rate
The percentage of product due as royalty.

Royalty Rate Code
SEE: Federal Royalty Rate Code.

Royalty Sales Quantity
The share of total lease sales volume which is reserved for the mineral interest or fee owner.

Royalty Sales Value
The portion of the value, received from the sale of a quantity of a product, that is payable to the royalty owner.

Royalty-in-kind
The royalty owner exercises his royalty interest by taking his share of the product(s) produced and marketing them rather than receiving his royalty portion of the value by the company. Also referred to as: RIK.

Royalty-in-kind Flag
An indicator of whether the take-in-kind interest owner has exercised the right to take the product(s) and market them rather than receive their royalty portion of the value received by the company when the company markets the product(s).

Rrc Record Number
A temporary number assigned to a well by the Texas Railroad Commission (RRC) to assist in identifying that well in subsequent processes.

Rubble Field
A region of deformed ice, usually composed of upturned blocks refrozen into an ice sheet. May contain a series of closely spaced ridges unseparated by sheet ice and has larger areal extent than a rubble pile.

Rubble Pile
An ice feature of areal, rather than linear extent, created by ice failing against a structure of a grounded feature.

Run
Oil taken from a tank for delivery.

Run A Tank
To transfer oil from a stock tank into a pipeline.

Run In
To go into the wellbore with tubing, drill pipe, etc.

Run Speed
The speed of the drillstring while heading in or out of the wellbore.

Run Statement
A monthly summary of run tickets given by the purchaser or operator of crude oil, detailing volume, gravity, price, and value of each run ticket.

Run Ticket
The basic legal instrument evidencing the volume, gravity, temperature, BS and W content, etc., of oil being delivered.

Run Ticket Number
An identifying number on the basic legal instrument used to record the run volume of oil.

Run Volume
The volume of crude oil sold and transferred to the pipeline by the producer.

Running A Free Point
Lowering a tool on a cable designed to measure the stretch in a stuck pipe, or using a free point indicator to determine the deepest point at which there is no cement behind pipe.

Running Casing
The act of latching onto casing with elevators, slips, and tongs and lowering casing into a wellbore.

Runoff
The portion of rainfall, melted snow, or irrigation water that flows across ground surface and eventually is returned to streams.

Runout
Intersection of the thread cone and the pipe outside surface. Location on the outer surface where the thread groove vanished.

Rupture Disc
A pressure relieving safety device, containing a frangible disc designed to break when pressure on one side exceeds a specified amount. Also referred to as: Safety Head; Safety Plug.