L
Laboratory Name
Name of the lab responsible for performing an analysis.
Lact
SEE: Lease Automatic Custody Transfer.
Lact Unit
An equipment assembly designed to measure, sample, and record liquid product volumes while delivering product to a pipeline on an unattended basis. Referred to as Lease Automatic Custody Transfer Unit (LACT).
Lact Unit Count
The number (count) of Lease Automatic Custody Transfer (LACT) unit(s) on a facility.
Lag Strokes
The total strokes (based on the pump(s) currently operating) during drilling operations being used for lagging cuttings, using either the calculation or tracer method.
Lagging
An insulating cover which prevents heat from flowing either to or from a piece of equipment.
Laggings
Removable and interchangeable drum spool shells for changing hoist drum diameter to provide variation in rope speeds and line pulls. This construction is optional with manufacturer.
Lahee Well Class
The well classification system as defined by Lahee.
Lambert Coordinate System
A system of coordinates on a conical projection based on two standard parallels.
Lamellar Tearing
A cracking phenomenon resulting from nonmetallic inclusions which occurs beneath welding principally in rolled steel plate fabrication.
Laminar Flow
Fluid elements flowing along fixed streamlines which are parallel to the walls of the channel of flow. In laminar flow, the fluid moves in plates or sections with a differential velocity across the front which varies from zero at the wall to a maximum toward the center of flow.
Lamination
A metal defect with separation or weakness generally aligned parallel to the worked surface of the metal.
Land Category Code
An indicator of the type of lease oragreement being reported on (i.e. single lease, communitized, unitized, non-unitized, etc.)
Land Cost
Includes the cost of land purchased, recording fees, and other costs incidental to the purchase of lands.
Landing Casing
To set the casing at a given depth along a wellbore path.
Landing Nipple
A receptacle in a production string with an internal profile to provide for latching and sealing of various types of plugs or valves.
Large Fracture Count
The number of fractures in a depth interval that are 10cm or greater in length.
Last Engaged Thread
The last thread on a pin engaged with the coupling.
Last Log Date
The date the last log was run.
Last Production Date
The month and year in which production last occurred.
Last Scratch
Last visible evidence of the machined thread tool mark on the pipe surface.
Late Delivery Penalty Flag
An indicator of whether or not there is a penalty for failure to commence taking gas by a set delivery date.
Late Payment Interest Amount
The interest calculated for late payment and or reporting.
Lateral
For a horizontal well, it is that portion of the wellbore from the kickoff point to the terminus.
Lateral Line
Pipeline segment that ties into a trunk line.
Laterolog
A resistivity log made with a tool which achieves focusing through the use of additional current electrodes above and below a central measure current electrode.
Latitude
Angle subtended with equatorial plane by a perpendicular from a point on the surface of a spheroid. A positive value denotes north.
Latitude Measurement
The distance measured north or south from the equator.
Latitude Shift Pole
Latitude of the rotated pole. Usually used when working with geological data.
Lattice Boom
Boom of open construction with angular or tubular lacing between main corner members (chords) in form of truss.
Launch ( Survival Capsule)
A platform or decking containing a motorized windlass/winch used for raising or lowering a survival capsule from a drilling production platform.
Lay Barge
A shallow draft, barge like vessel used in the construction and laying of underwater pipelines in swampy areas and to offshore platforms.
Laying Down
Usually means unscrewing the drillstem into single joints and placing them on the pipe rack.
Ldc
SEE: Local Distribution Company.
Leachate
Liquid that has percolated through solid waste or other medium and has extracted dissolved or suspended materials from the medium.
Leaching
The process by which soluble materials in the soil, such as nutrients, pesticide chemicals, or contaminants are washed into a lower layer of soil or are dissolved and carried away by water.
Lead
(1) On a decanting centrifuge, the slurry conducting channel formed by the adjacent walls of the flutes or blades of the screw conveyor.(2) The distance that a thread moves along its longitudinal axis.(3) The distance from a point on a thread to a corresponding point on the next thread, measured parallel to the axis of the thread section.
Lead Acetate Test
A test for determining whether the hydrogen sulfide content of a gas stream is in excess of about 0.25 grains per 100 cubic feet of gas.
Lead Angle
A method of setting the direction of the borehole axis in anticipation of the drill bit walking.
Leading Flank
The flank of the pipe thread facing the near end of pipe. The flank of the coupling thread facing the open end of the coupling. Also referred to as front flank or stab flank.
Leak
The accidental escape from a process component of liquid and/or gaseous hydrocarbons to atmosphere.
Leak Locator
An electrical device for locating leaks underground.
Leakage Field
The magnetic field forced out of the material into the air by the distortion of the field within the material caused by the presence of a discontinuity.
Leaker
A length of pipe that will not hold hydrostatic pressure.
Leakoff Test
A gradual pressurizing of the casing after blowout preventers have been set to permit estimation of the formation fracture pressure at the casing seat.
Leakoff Test Pressure Measurement
The pressure exerted on the wellbore bottom before or after the squeeze operation has been completed to determine the maximum pressure the reservoir rocks can withstand without rupturing or fracturing. The pressure is expressed in terms of a full column of drilling fluid having a certain density (hydrostatic head).
Lean Amine
Stripped aqueous monoethanolamine (MEA) or diethanolamine (DEA) solution.
Lean Gas
Natural gas containing little or no liquefiable hydrocarbons.
Lean Oil
The absorbent oil in a gasoline absorption plant from which the absorbed gasoline fractions have been removed by distillation.
Lease
A term used ambiguously. Resulting from a legal document, the term has taken on various meanings depending on the context in which it is used. It is preferable to use terms with explicit definitions which remove ambiguity.
Lease Abandonment Authorized Cost
The estimated costs associated with abandoning the lease.
Lease Acquisition Date
The date a lease was acquired which may be different from the lease effective date.
Lease Agreement Name
The name assigned by a regulatory agency to a lease or agreement.
Lease Agreement Number
The regulatory assigned number to identify various types of leases or agreements; e.g., unitization, Indian., communiitization, etc.
Lease Agreement Type Code
An indicator of the type of Federal, State, Crown, Indian, and other governmental agency lease and/or license. Examples include: Federal acquired options, Bituminous sands (Canada), crossing agreement (Canada), Crown natural gas (Canada), Communitization agreement.
Lease Assignee Name
The name of the party (lessor) assigning a lease to the lessee.
Lease Assignment Date
The date on which the lease assignment is executed.
Lease Automatic Custody Transfer
The process of utilizing equipment (measuring, monitoring, recording, and transferring) for custody transfer of liquid products in order to eliminate the need for any manual activity. Commonly abbreviated as LACT.
Lease Bid
A timely, sealed submittal to a mineral owner offering a monetary consideration for a specific property during a lease sale.
Lease Check Type
The category of recipient of the lease rental; e.g., depository bank; direct.
Lease Class
Indicates whether a lease is classified as oil or gas, normally determined by a regulatory agency.
Lease Description
The legal description of the included lands given in terms of boundary lines of the applicable mapping system on the executed lease document.
Lease Effective Date
The date on which a lease instrument becomes valid.
Lease Expiration Date
The date that the primary term of the mineral lease instrument expires.
Lease Facility
Facility such as a dehydrator, compressor, or separator installed to serve only a single lease.
Lease Form Number
The number identifying a standard form used for a lease instrument.
Lease Gross Rental
Total amount of all rentals for a given lease.
Lease Gross Value
The gross value before taxes for an accounting lease.
Lease Gross Volume
The total volume on which proceeds are distributed to owners of the property. This volume may be total lease volume, actual sales volume, or entitled volume depending on the type of settlement used for the specific accounting lease.
Lease Instrument
The legal instrument by which a leasehold is created in minerals. A contract that, for a stipulated sum, conveys to an operator the right to drill for oil and gas. The oil lease is not to be confused with the usual lease of land or a building (lease property).
Lease Mineral Type
Specifies the mineral to be produced from the area of land covered by the original mineral lease; e.g., oil; gas; uranium; geothermal; oil shale; tar sand; metallic mineral; sulphur; salt.
Lease Name
The name assigned to a lease by the regulatory agency having jurisdiction over mineral activity in the territory where the lease is located.
Lease Net Rental
The portion of the lease gross rental which is payable by the indicated company.
Lease Number
The number assigned to a lease by the regulatory agency having jurisdiction over mineral activity in the territory where the lease is located.
Lease Operator
The Business Associate charged with the responsibility of operating all wells and equipment on a lease. May be required to test wells, gauge tanks, make minor repairs to maintain well production, make reports of production and sales, etc.
Lease Operator Flag
An indicator of whether the reporting party is the operator.
Lease Operator Name
SEE: Operator Name.
Lease Parcel
A specific tract of the Earth defined by areal extent and possibly depth (numeric depth range or stratigraphic units). The lease parcel is the basic unit of ownership for portions of the Earth; it may be onshore or offshore.
Lease Parcel Agreement
A legal document that conveys the right to win, take, and explore for mineral resources, or that conveys the right to access and occupy an area of the Earth.
Lease Parcel Alias
An alternate unique name assigned to a lease parcel.
Lease Participation Percentage
The percentage of production that a lease will be allocated from a unit.
Lease Platform Approval Date
The date that the first platform is approved for a lease by the regulatory agency.
Lease Producing Completions Count
The number of completions that produce from a lease.
Lease Property
SEE: Lease Parcel.
Lease Release Date
The date that a lease instrument was released.
Lease Rental Partner
A partner to be billed for lease rental.
Lease Rental Payment Date
The date a delay rental payment was made on a mineral lease.
Lease Reoffered Flag
An indicator that a block or bidding entity has expired, terminated, been relinquished, or been rejected and is reoffered in a subsequent lease sale.
Lease Royalty Rate
The lessor's decimal share of the wellhead value of minerals on a lease.
Lease Shut- In Clause Flag
An indicator that a lease instrument has a shut- in clause.
Lease Status Code
An indicator of the lease status or contract arrangements such as arms length, all dispositions, and RIK indicators.
Lease Stipulation
Operational restrictions or requirements imposed on a block or lease which addresses site specific conditions not encompassed by standard lease terms.
Lease Term Initial Period
The primary term, in years, of a lease. May be for a fraction of a year.
Lease Term Period
The number of years following lease issuance that the lessee can withhold exploration, development, and production activities without the lease being subject to forfeiture.
Lease Total Completion Count
The total number of completions on a lease.
Lease Tract Number
An internally assigned number to identify a tract of land within a lease.
Lease Type
The classification of a lease; e.g., fee; state; Federal.
Lease Type Code
Identifies the type of lease; e.g., fee; state; Federal Acquired; Contested; Federal Public Domain; Indian Alloted; Indian Tribal.
Lease Unit Nonparticipating Acreage
The total lease surface area for that portion of the unit that is not receiving unit allocation.
Lease Unit Participating Acreage
The lease surface area that has been made part of and is receiving an allocation from a unit agreement.
Lease Unit Reservoir Acre Feet Volume
The total acre feet of all the reservoirs that have been included in a unit agreement and which underlie a lease.
Lease Use Gas Nonexempt Volume
The lease use volume in excess of allowances.
Lease Use Volume
The volume of product used on lease for fuel, lift, etc.
Lease Well Count
The total number of wells on a lease.
Leasehold
A tract of land, on which a lease has been obtained, for the purpose of exploration and development of hydrocarbons. Such leases typically describe the right to produce by surface boundaries or subsurface intervals or boundaries.
Leasehold Acres
Acreage on which a party (lessee) has acquired, by lease, the right to explore for and produce oil, gas, and/or other minerals in return for a stated royalty, and possibly other considerations.
Leasing Agreement
SEE: Lease Instrument.
Left Lateral Strike Slip Fault
A strike slip fault in which the opposite fault block has moved relatively to the left, with the predominate motion being strike slip. Also referred to as: Sinistral Fault.
Left Longitude Of Area
The westernmost longitude of an area.
Legal Subdivision Number
Smallest division in the Canadian township-range-section survey system.
Lens
A lentil shaped bed of rock that pinches out or lenses out in all directions.
Lessee
The one to whom a lease is granted.
Lessee Identification Number
An identifier of the name of the lessee.
Lessee Name
The name of lessee.
Lessor
The one who grants a lease.
Lessor's Mineral Interest
The interest in minerals owned by the lessor.
Letter Of Indemnity
An agreement in which a party receiving gas sales proceeds agrees to refund part of such proceeds in the event the Federal Energy Regulatory Commission (FERC) orders the party to return part of the gas sales proceeds to the purchaser because a portion of the rate is deemed unjustified.
License
SEE: Permit.
Life Cycle Cost
Total cost of ownership of a commodity; includes initial purchase price and estimated administrative , operating and maintenance costs over the anticipated life of the item.
Lifting Cost
The cost of producing oil from a well or a lease.
Light Crude Oil
(1) Crude oil that flows freely at atmospheric temperature and has an API gravity in the high 30's and low 40's.(2) A light colored crude oil.
Light Discharge
SEE: Overflow.
Limb
The area of a structural fold between adjacent fold hinges.
Limestone
A sedimentary rock consisting chiefly (more that 50% by weight) of calcium carbonate, primarilly in the form of mineral calcite, and with or without magnesium carbonate. Specifically, a carbonate containing more than 95% calcite and less than 5% dolomite.
Limit Order
An instruction to purchase or sell a futures contract that specifies the maximum price to pay or minimum price to accept.
Limited Partnership
An agreement between two or more parties providing for at least one of the parties having limited liability.
Limited Ventilation
Ventilation (natural or artificial) which is sufficient to reasonably assure that significant quantities of vapor and air mixtures in concentrations above 25% of the lower flammable (explosive) limit (LEL) will not accumulate for significant periods of time due to hydrocarbon emissions which are relatively small in size or short in duration.
Line Item Balance Due Amount
The difference between the amount due and the amount paid for a line item.
Line Item Due Amount
Line Item Due Date
The amount due for a line item.
Line Item Paid Amount
The amount originally paid for a detail line.
Line Number
The line number of each individual transaction in a royalty report.
Line Pressure Measurement
The measured pipeline pressure into which the well is flowing at the time of the test.
Line Recording Direction
The general azimuthal direction along which a seismic line is physically recorded.
Linear Imperfection
An imperfection that includes, but is not limited to, seams, laps, cracks, plug scores, cuts and gouges.
Liner
(1) A short string of casing that does not extend up to the surface. Liners are suspended from an existing casing string by a liner hanger.(2) The lining of barrels of pumps.
Liner Base Depth
The measured depth to the base of the liner.
Liner Cement Quantity
The quantity of cement used in cementing the liner in place in the wellbore.
Liner Inside Diameter
The inside diameter of the liner.
Liner Outside Diameter
The outside diameter of the liner.
Liner Set Date
The date the liner was set in the wellbore.
Liner Top Depth
The measured depth to the top of the liner.
Liner Type
The type of liner used; e.g., coal protecting; gravel packed; preperforated; slotted.
Liquefiable Hydrocarbon
The hydrocarbon component of natural gas which can be extracted and saved in liquid form.
Liquefied Natural Gas
SEE: Natural Gas Liquid.
Liquefied Petroleum Gas
A mixture of gaseous paraffinic hydrocarbons composed principally of butane, ethane and propane, but not pentanes and heavier products. These gases, easily liquefied at moderate pressures, may be transported as liquids but converted to gas on release of the pressure. Commonly abbreviated as LPG.
Liquid
A substance which flows readily, does not tend to expand indefinitely like a gas, assumes the form of its container while retaining its independent volume, and has form which can be seen and felt.
Liquid Charge Type
A type of charge deducted from the lease value for liquids determined by volume of liquid produced.
Liquid Deduction Type
The type of deduction to be applied to the base liquid price for a particular state, gathering system, etc.
Liquid Diamondoid
One of a series of saturated polycyclic hydrocarbons in a cage like configuration with formulas of C10, H16, C14, H20, etc. with a melting point of approximately 500 degrees F. These are very unstable long chain hydrocarbons. They occur in very dry gas and precipitate out at atmospheric pressures and temperatures.
Liquid Discharge
That stream from a liquid solids separation device which contains a higher percentage of liquid fraction than does the feed.
Liquid Hydrocarbon
SEE: Natural Gas Liquid.
Liquid Level Controller
A device that measures and regulates the amount of fluid in a vessel.
Liquid Meter
A measurement device to determine volume of liquid passing a given point in line. Usually calibrated in barrels or gallons.
Liquid Overflow
The discharge of liquids from a process component through a gas (vapor) outlet.
Liquid Packed
In horizontal treaters, the coalescing section or entire treater may operate completely full of liquid. Also referred to as fluid packed.
Liquid Products Price Per Unit Amount
The value per unit of measure of liquid
Liquid Recovery Minimum Percentage
The minimum percentage of liquids which must be recovered from gas being processed under a certain contract. This is attributable to each liquid component recovered.
Liquid Settlement Type
Indicates the type of settlement made for liquid under a contract; e.g., monetary; in kind.
Liquid Sump
A vessel installed below grade into which open drain system effluents are flowed.
Liquids Returned Nonexempt Volume
The volume of liquids returned to lease in excess of allowances.
Liquids Returned Volume
The volume of liquids used on lease for fuel, lift, etc.
Lithofacies
The rock record of any sedimentary environment, including both physical and organic characteristics.
Lithologic Body
A subsurface body characterized by its lithologic content or character.
Lithologic Log
A log plotting lithology versus depth. Lithology can be shown by colors or by symbols, or both. A strip log is usually based on sample examination. A lithologic log may be a computed log is derived from other well logs.
Lithology
The description of rocks, especially in hand specimen and in outcrop, on the basis of characteristics; e.g., color; mineralogic composition; grain size.
Lithology Major Rock Type
SEE: Lithology.
Lithology Modifier
Modifier of a lithologic description.
Lithology Sample Taken Flag
An indicator of whether a lithological sample was collected for a well.
Lithology Type Code
An indicator of the type of lithology; e.g., sandstone, salt, dolomite, coal.
Lithostatic Pressure
The pressure at a specified depth exerted by the weight of the overlying rock column.
Lithostratigraphic Unit
A geologic body characterized by its position within a lithology and chronology-based classification of rock units. Unit hierarchy is described by terms such as group, formation, member, and marker.
Lithostratigraphy
The branch of Stratigraphy dealing with the lithology of strata and with their organization into units based on lithologic character. Also referred to as: rock stratigraphy.
Live Oil
Crude oil that contains gas and has not been stabilized or weathered.
Live Roller Circle
An assembly of multiple swing rollers free to roll between revolving upperstructure and mounting.
Lng
SEE: Liquified Natural Gas.
Load Binder
(1) Chain or rope used to tie down loads of equipment.(2) The boomer used to tighten the chains; i.e., ties pipe down for transportation.
Load Factor
The ratio of average load to the maximum demand during a given period, expressed as a percentage.
Load Oil
SEE: Frac Oil.
Load Rating
A crane rating as established by the manufacturer.
Load The Hole
The action of filling the wellbore with some liquid to provide a hydrostatic head to control high reservoir pressures and to force acid, hydrafrac process or other treatment fluids into the reservoir rocks being treated.
Load Working
The external load applied to the crane including the weight of load attaching equipment such as load block, shackles, and slings.
Loading Rack
A loading platform with pipes and hoses at the side of a railroad track for loading various products into tank cars or in a facility for loading trucks.
Local Dihedral Angle
The dihedral angle between tangent surfaces at a given point along a weld joining two curved surfaces.
Local Distribution Company
Companies which purchase gas for resale to end users, such as residential or commercial customers within an urban or rural area. Commonly abbreviated as LDC.
Local Vertical Datum
A set of fundamental elevations to which other elevations are referenced. These fundamental elevations are determined for a country or continent through measurements in a network of reference benchmarks which are connected to sea level.
Location
Position on the earth's surface.
Location Basis Swap
Swap which typically involves one party paying the counterparty the NYMEX last three days +/- a location basis differential and receiving a specified monthly pipeline index price.
Location Direction
The direction from a speciific reference point.
Location Distance
The distance from a refernce point or reference line.
Location Exception Order Number
An identifier of an order or authorization by a regulatory agency permitting a well within a drilling and spacing unit to be drilled in an off-pattern location.
Location Exception Order Number Assigned Date
The identifier of an order or authorization by a regulatory agency permitting a wellwithin a drilling and spacing unit to be drilled in an off-pattern location.
Location Exception Saskatchewan
The location exception code (columns 2-3 of the Canadian Petroleum Association (CPA) well number) Dominion Land Survey (DLS) reported wells in Saskatchewan.
Location System Code
An indicator of the system used to define a location; e.g., latitude-longitude; x-y; metes and bounds; section-township-range; descriptive.
Location To A Lease Distance
The distance from a reference point or line to a lease.
Location To A Well Distance
The distance from a refernce point or line to a well.
Lock Out
A system to specify that equipment is out of service until locks or tags are removed by the authorized person. Also referred to as tag out.
Locked In
Refers to the condition where the bottomhole assembly is held relatively fixed within the borehole by the outer diameter of the assembly being nearly the same diameter as the drill bit, the inclination and direction of the borehole axis are maintained.
Locomotive Piston
A swabcup unit used to transport and manipulate TFL tools, which are tools that work "thru flow line" (TFL).
Log
(1) A regularly kept record or journal, including results of sampling or interpretation of data with respect to a coordinate system, such as time, depth, or distance.(2) The act of producing or updating a log.
Log Curve
A trace representing a continuous record of some property or occurrence in the borehole environment versus depth. One or more curves may constitute a well log.
Log Curve Base Depth
Deepest measured depth for a log curve.
Log Curve First Reading
The measured depth of the first usable reading or value recorded for a log curve at the onset of the survey. This depth differs from the log curve base depth, due to curve memorization or to a delay in sensor movement with respect to cable movement as measured at surface.
Log Curve Id
An identifier for a log curve which, when used in combination with context information for the logging job, serves to distinguish it from all other log curves. Often this identifier is a code or mnemonic supplied by the logging company.
Log Curve Index Id
Identifier for a data array which is used as an index for the data corresponding to a log curve.
Log Curve Index Type
Type of index for a particular log curve; e.g., true vertical depth; measured depth; two way time.
Log Curve Name
A descriptive log curve identifier, generally used for labeling log curves for visual recognition.
Log Curve Sample Rate
Time or depth interval between successive value samples on a log curve.
Log Curve Top Depth
Shallowest measured depth for a log curve.
Log Curve Type
General classification for log curves, independent of the specific sensor type used; e.g., gamma ray; caliper; formation density; resistivity; SP.
Log Data Method
The method of obtaining the log data; e.g., wireline log; mud log; drilling log.
Log Digitizer
(1) Company or person that digitized the log.(2) An electromechanical device that scans and digitizes a log.
Log Digitizing Date
The date the log was digitized.
Log Permanent Datum
The permanent elevation reference entity, independent of the equipment at the location. Generally, mean sea level (MSL) or ground level (GL) is used.
Log Repeat Section
A log rerun over a short section of the borehole, generally 200 feet, to enable comparison of similarity with the main survey to show instrument stability and repeatability.
Log Run Number
An integer that indicates one of a series of distinct and different occasions that loggers have run equipment down the wellbore to take measurements.
Log Start Time
Date and time a particular log run was started.
Log Status Code
An indicator of information pertaining to a well log.
Log Stop Time
Date and time a particular log run was completed.
Log Trace
A curve on a well log.
Log Type
An identifier of the type of log run; e.g., acoustic log; caliper log; dipmeter; microlateral log.
Log Zero Depth Reference
The elevation reference (datum) from which logging depths are measured. Typically, the logging engineer sets the depth measurement system to zero while the measure point of the logging tool is positioned at this reference point. Frequently used reference points are derrick floor (DF) or kelly bushing (KB) for open-hole logging, casing flange for production logging.
Logged Interval Base Depth
The deepest (base) depth included in this logged interval.
Logged Interval Top Depth
The shallowest (top) depth included in this logged interval.
Logging Company Name
Name of the service company that logged the well.
Logging Depth Reference Elevation
Elevation of the Logging Zero Depth Reference above the Log Permanent Datum.
Logging Direction
Direction in which the logging tool was moving when the data were recorded, either up or down.
Logging Engineer
The person who does the well logging at the wellsite.
Logging Operation Start Time
Date and time the logging company rigged up to start logging.
Logging Operation Stop Time
Date and time the logging company rigged down after completion of well logging operations.
Logging Speed
Speed at which a particular log run was made, generally taken as the speed of the logging cable measured at surface. The actual speed of the logging tool may differ considerably from the cable speed; it can be measured with the use of accelerometers.
Logging Tool
The equipment used to perform well logging.
Logging Unit Id
Unique identifier for the surface equipment used in the logging operation.
Logging Unit Type
Type of surface equipment used in the logging operation.
Long Natural Gas Position
When a company produces more natural gas than it consumes in its operations.
Long Spaced Sonic Log
Long spaced sonic well logging tools are used to provide shear wave analysis, travel time through casing, and more accurate acoustic data in enlarged boreholes and in areas where rocks surrounding the borehole are altered by the drilling process.
Longitude
Angle measured about the spheroid axis from a local prime meridian to the meridian through the point. A positive value denotes east.
Longitude Measurement
The distance measured east or west of the prime meridian, as from Greenwich, England.
Longitude Shift Pole
Longitude of the rotated pole. Usually used when working with geological data.
Longitudinal Imperfection
An imperfection which has its principal direction or dimension in the approximately longitudinal direction.
Longitudinal Seam
A butt welded seam which parallels the axis of the pipe.
Longitudinal Wave
SEE: P Wave.
Loop
(1) A curved section of tube bent to a minimum 5 foot (1.524 m) radius allowing change in direction of Thru Flow Line (TFL) lines.(2) A section of pipe substantially parallel with, and connected at both ends to another line to increase flow rate or to decrease pressure drop.
Loose Flange
A flange, as manufactured, not intended to be made integral with another piece of API Spec 6A equipment. They are blind, threaded, spacer, welding neck, and studded adapter flanges.
Loose Gear
Includes all slings, nets, hooks, baskets, shackles, chains, ropes, cables, life vests, etc., necessary in crane operations to attach the load to the crane hook or block and to move the load.
Loss Of Back Reflection
Absence of or a significant reduction of an indication from the back surface of the article being inspected.
Lost Circulation
Loss of drilling fluid into the rocks surrounding the borehole during drilling operations.
Lost Circulation Depth
The measured depth at the lost circulation event occurred.
Lost Circulation Interval
The measured depth interval within which a lost circulation event occured.
Lost Circulation Interval Base Depth
The measured depth to the base of the lost circulation interval.
Lost Circulation Interval Top Depth
The measured depth to the top of the lost circulation interval.
Lost Circulation Material
A material added to cement slurries or drilling fluids which is designed to prevent the loss of cement or mud to the rocks surrounding the borehole.
Lost Circulation Material Added Quantity
The quantity of material added in treating the lost circulation interval.
Lost Circulation Material Concentration
Measurement of any sealing material added to the drilling fluid to control loss of circulation.
Lost Circulation Material Type
The type of material used in treating the lost circulation interval; e.g., cane; chicken feathers; hay; mica; walnut hulls.
Lost Circulation Treatment Material Name
The brand or trade name of the lost circulation material used in treatment.
Lost Circulation Volume
The measured amount of drilling fluid lost in the lost circulation interval.
Lost Circulation Zone Treated Date
The date the lost circulation interval was treated.
Lost Oil Volume
The volume of oil unavoidably lost and not considered to be recoverable.
Lost Percentage
The percentage resulting from subtracting the sum of the total recovery percentage and the residue percentage from 100.
Lost Return
SEE: Lost Circulation.
Lost Section
SEE: Missing Section.
Lot In Township Or Farm
The lot within a township, farm or city tract.
Lot Number
The number assigned by an administrative agency to a specific parcel of land as a result of a cadastral survey.
Low Flow
Flow in a process component less than the minimum operating flow rate.
Low Liquid Level
Liquid level in a process component below the lowest operating level.
Low Pressure
Pressure in a process component less than the minimum operating pressure.
Low Pressure Sensor Setting
The setting of a device in a process component set to alarm when the pressure is less than the allowable minimum operating pressure.
Low Temperature
Temperature in a process component less than the minimum operating temperature.
Low Temperature Separator
SEE: LTX Unit; Separator.
Lowcut
Frequency designator specific to a frequency where the filter's amplitude response is attenuated 3 decibels (to 70% amplitude or half power) of the total signal amplitude. Frequencies less than the lowcut are reduced by more than 3 decibels, and frequencies greater than the lowcut are reduced by less.
Lower Explosive Limit
The lowest concentration by volume of combustible gases in mixture with air that can be ignited at ambient conditions.
Lpg
SEE: Liquified Petroleum Gas.
Ltx Unit
A low temperature separator. A mechanical separator which uses refrigeration obtained by expansion of gas from high pressure to low pressure to increase recovery of gas entrained liquids.
Lubricator
(1) In an oil field, in addition to its ordinary meaning, the term is applied to special devices for introducing chemicals, fluids, and instruments into a system under pressure. Example: oil and mud lubricators.(2) An apparatus injecting lubricating oil into engine power cylinders and compressor cylinders between the piston and liner.
Luster
The appearance of a mineral in reflected light; e.g., dull; earthy; metallic.
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