This is a glossary of terminologies typically used in the oil and gas industry that could be useful to HootDex members.
A #
Abandon: To pause or stop drilling operations or production from a well. Reasons for abandoning are if a well is a dry hole or if it’s not producing enough to be kept active.
Abatement: (1) The act or process of reducing the intensity of pollution.(2) The use of some method of abating pollution.
Absentee Bid: This process allows a bidder to participate in an auction without being present. An absentee bidder will usually submit their offer before the auction and they need to follow the guidelines set in place by the auctioneer.
Absolute Auction: Also known as an auction without reserve, absolute auctions don’t have any limiting conditions or amounts. The property under auction will be sold to the highest qualified bidder.
Abstract of Title: The historical ownership records for a property. These records include surface rights and mineral rights among other details.
Accredited Investor: When a person or institution is considered capable of understanding and affording the financial risks of unregistered securities, they are known as an accredited investor. The federal securities laws have more specific guidelines for who qualifies as an accredited investor in Rule 501 of Regulation D:
- The institution is a bank, insurance company, registered investment company, business development company, or small business investment company.
- An accredited investor can be an employee benefit plan if a qualified individual or organization (as identified above) makes the decision or the plan has assets over $5 million.
- The institution is a charitable organization, corporation, or other partnership with assets over $5 million.
- The person is an executive or partner of the company selling the unregistered securities.
- The institution has equity owners that are accredited investors.
- The individual has a personal, or joint net worth of over $1 million.
- The individual has had a personal income of at least $200,000 for the past two years, or a joint income of at least $300,000. The income expectation for the next year must also be the same.
- A trust with over $5 million in assets managed by a person capable of understanding the risks of unregistered securities is qualified. The trust’s original intent must not have been to purchase the securities offered.
Adsorption: A surface-based process where a substance’s atoms, ions, or molecules adhere to the adsorbent.
Adsorption Oil: Also known as wash oil, this light liquid hydrocarbon is used in wet gas streams to absorb or remove heavier liquid hydrocarbons.
Acidizing: To increase the flow of oil or gas in drilling, hydrochloric acid can be pumped into the well. The acid works to break down limestone, reducing the restrictions the oil or gas was previously facing to increase flow.
AESC Association of Energy Service Companies: This association provides training materials and represents the interests of energy service employees within the oil and gas industry.
Alkaline Flooding: Also known as caustic flooding, the alkaline flooding process involves injecting alkaline chemicals during polymer flooding or waterflooding. Sodium hydroxide, sodium carbonate, or other alkaline chemicals react with specific types of oils, and this reaction results in surfactants. These surfactants then increase oil production by reducing interfacial tension between oil and water. Alkaline flooding shouldn’t be used in carbonate reservoirs.
Aluminum Stearate: A salt mixture of aluminum hydroxide and stearic acid typically mixed with oil. The resulting solution is sprayed on foamy water mud to release gas bubbles from the mud.
Aniline Point Test: A test of oil mud to determine if the aniline point temperature (aninline point) of the oil will damage elastomers (rubber compounds). The aniline point corresponds to the amount and type of hydrocarbons found in an oil sample, so a low aniline point indicates higher aromatics, and vice versa.
Annular Velocity: Speed of drilling fluid or cement movement in a well column (typically measured in feet/minute or meters/minute)
Annulus: An area between two concentric objects where fluid can flow. An example is the space between the wellbore and casing or the space between casing and tubing.
Anticlines: Anticlines are folds in the earth’s surface where at least 80% of the world’s oil and gas has be found. An anticline has strata that slope downward on both sides and usually has surface formations like hills, knobs, and ridges.
API American Petroleum Institute: This oil and gas industry trade organization publishes standards and best practices related to the industry.
Api County Code: An indicator developed by the American Petroleum Institute (API) to identify areas such as counties and other subdivision areas identified within state boundaries. Defined by API Bulletin D12A, as amended. This code becomes a part of the API Well Number.
API – Monogram: The logo of the American Petroleum Institute (API) is added to equipment that meets their minimum standards. API also provides industry-related publications about recommended practices and standards.
Api State Code: The indicator assigned to a state, as defined in API Bulletin D12A, as amended. This code is a part of the API Well Number (The Api State Code for Colorado is 05).
Api Well Number: A well identifier assigned as defined in API (American Petroleum Institute) Bulletin D12A, as amended. The API Well Numbers are assigned by the appropriate state or federal regulatory agency.
Appraisal Well: A well drilled as part of an appraisal drilling program which is carried out to determine the physical extent, reserves and likely production rate of a field.
Aromatic Content Test: A quantitative test for measuring aromatic content of base oils used in oil mud.
Artificial Lift: Used to describe any method for retrieving oil from a well and bringing it to the surface after the well ceases to produce.
Asphaltic Mud Additive: Solid or high-viscosity hydrocarbons found in natural deposits or in petroleum refining residue that are used as additives of oil- and water-based muds (drilling fluids).
“As Is”: Also known as “As Is, Where Is” and “In Its Present Condition”, “As Is” states there are no guarantees about the condition or usage of the property. The buyer is responsible for determining its condition and use cases.
Assignee: The person who a property’s interests, like a working interest, royalty, or net profits interest, are assigned to.
Assignor: The person who expresses interest in a particular assignment.
Associated Gas: Natural gas that’s created with crude oil from the same reservoir.
Auction With Reserve: The opposite of an absolute auction, auctions with reserves have minimum buying prices that may not be disclosed to the bidders. The seller also has the ability to deny a bid for any reason.
Authorization for Expenditure: Abbreviated as an AFE, this is a proposal given to each stakeholder that estimates the cost of drilling and completing a proposed well. The proposal will contain dry hole costs, completion costs, and the total cost. Dry hole costs are the spend needed to drill to the casing point, while completion costs are the funds needed to complete the well.
B #
Back In: Typically used to describe the payout to investors for their initial well investment, a back in is a type of interest in a well or property that becomes effective at a future time or after a future event.
Baffle: The part of a separation vessel used to temporarily slow the flow of fluids; needed when attempting to separate oil and water.
Bail: A steel bar that supports the swivel and connects it to the hook; resembles the handle of a bucket.
Bailer: A cylindrical container with a valve used in cable-tool drilling; used to remove oil, water, sand, and mud from a well.
Barrel of Oil Equivalent (BOE): The amount of oil barrels produced from a site each day.
Base Oil: Simply put, base oil is the continuous phase in oil-based drilling fluids (water-in-oil emulsions where water is in the dispersed phase and oil is in the continuous phase).
BBL: BBL is simply the abbreviation for barrel. For context, a barrel of oil is 42 US gallons.
Bit: A steel bar that supports the swivel and connects it to the hook. Resembles the handle of a bucket.
Bitumen: An extremely viscous form of crude oil that contains sulfur and other metals; to be produced, bitumen must be heated or combined with lighter hydrocarbons.
Blind Pool: An oil and gas limited partnership that has not committed to a single lease or property yet.
Block: An acreage sub-division measuring approximately 10 x 20 kms, forming part of a quadrant. e.g. Block 9/13 is the 13th block in Quadrant 9.
Blow Down: Condensate and gas is produced simultaneously from the outset of production.
Blowout: Occurs when down-hole pressure gas is not properly balanced with the weight of the drilling mud; the uncontrolled flow of gas, oil, or other fluids.
Blow-out preventers (BOPs): Are high pressure wellhead valves, designed to shut off the uncontrolled flow of hydrocarbons.
Bore: As a noun, a bore is the inside diameter of a pipe or drilled hole. As a verb, bore means to penetrate a surface with a rotary tool.
Borehole: Also known as the wellbore, a borehole typically refers to the openhole or uncased portion that is created in well drilling.
Bottomhole: As the name suggests, the bottomhole is the deepest part (the bottom) of the well.
Broker Participation: In this situation, brokers will register potential bidders for properties being sold at an auction. The brokers are paid through commission by the property owner or auction firm.
BTU: An acronym for British Thermal Unit, BTU is a measurement to describe the amount of heat generated from burning oil or gas.
Burner Valve: There are two instances where burner valves are used. The first is in a dehy unit or line heater where it maintains a constant temperature in the process bath by controlling the flow of gas to the fire tube. The second is on a heater treater where constant temperatures are maintained in the vessel by the burner valve.
C #
Cable: A rope, wire or braid of strong fibers.
Cased Hole: A well that has the casing already inserted. The opposite of a cased hole is an open hole.
Casing: A steel pipe that’s placed in an oil or gas well after drilling is completed to prevent the well hole from caving in. Casing also prevents fluids from moving from one formation (like groundwater) to another and helps in well control.
Casing Tongs: A large wrench used for turning casing tubulars when making up or breaking out casing.
Cavitation: Describes the continuous pumping of mud from surface-level mud tanks, down the drill pipe, out the drill bit nozzles, and through the gap between the drill pipe and the borehole to the surface. This movement carries rock cuttings via the shale shaker to the mud system.
Central Estimate: A range of exploration drilling scenarios from which the following activity levels, based on recent historical experience, are adopted as the central estimates.
Check Stub: The stub attached to a check that includes relevant information like the well name, production month, total volume produced, price received, and the net decimal interest of the payee.
Christmas Tree: The assembly of fittings and valves on the top of the casing which control the production rate of oil.
Circulation: Caused by quick changes in pressure, cavitation is the creation of vapor cavities within a low-pressure liquid. Cavitation can cause severe wear through cyclic stress on metal surfaces as they implode.
Coiled Tubing: A long, but small in diameter pipe that is used to replace jointed pipes in certain types of drilling, completion, and workover operations.
Commercial Field: An oil and/or gas field judged to be capable of producing enough net income to make it worth developing.
Commercial Well: A well that produces enough to pay for it’s production costs and leave enough oil and gas to be sold for revenue.
Completion: Used to describe all activities between drilling to casing point and putting the well to production. Includes cleaning out the well bore, setting the casing and tubing, adding surface equipment, and perforating the casing.
Compressor: An engine that is used to increase natural gas pressure so that it can more easily flow through the pipeline.
Concession: A government grant awarded to oil and gas companies to explore and produce oil and gas – usually on government-owned property. Typically, the government receives a bonus or license fee and a portion of the production.
Condensate: Hydrocarbons which are in the gaseous state under reservoir conditions and which become liquid when temperature or pressure is reduced. A mixture of pentanes and higher hydrocarbons.
Conventional Resources: Hydrocarbon accumulation within highly permeable rocks that tend to have high-recovery factors.
Conveyance: Used to describe the legal transfer of property from one owner to another via a deed or bill of sale.
Coring: Taking rock samples from a well by means of a special tool — a “core barrel”.
Cost Oil: Specified in the production sharing contract, cost oil is applied annually by the operator to recover costs.
Counterbalance Weight: As the name suggests, a counterbalance weight is used to balance an existing weight. Often used in oil production pumping units to balance the weight of the upstroke (fluids and the column of the sucker rod) and downstroke (rods) of the pump.
Crane Barge: A large barge, capable of lifting heavy equipment onto offshore platforms. Also known as a “derrick barge”.
Crude Oil: Oil’s form as it comes directly from the ground; it’s a mixture including naturally occurring liquid hydrocarbons.
Cubic Foot: A standard unit used to measure quantity of gas (at atmospheric pressure); 1 cubic foot = 0.0283 cubic meters.
Cuttings: Rock chips cut from the formation by the drill bit, and brought to the surface with the mud. Used by geologists to obtain formation data.
D #
Dead Oil: Thick oil or residue that’s at such a low pressure that no dissolved gas or volatile elements are present.
Deed: A legal document used to transfer a property’s title from a person (or organization) to another.
Deepen: To increase the distance below a specified reference datum.
Delay Rental: Paid to the lessor by the lessee, this consideration extends the oil and gas lease terms when there is no operations or production. The payment typically gives the lessee another year, however, if no payment is made and operations cease, the lease is considered abandoned.
Density Log: This radioactivity contact log responds to variations in the specific gravity of formations by emitting neutrons and measuring the secondary gamma radiation from the detector to the instrument. This is particularly helpful when measuring porosity in shale sands.
Depletion: The loss in mineral deposits as the well is produced.
Depletion (Gas) Drive: An income tax deduction that can be taken advantage of for exhausting a natural resource.
Depreciation Allowance: The loss in mineral deposits as the well is produced.
Derrick: The tower-like structure that houses most of the drilling controls.
Development Phase: The phase in which a proven oil or gas field is brought into production by drilling production (development) wells.
Development Well: A well that’s drilled in a proven oil or gas reservoir at the depth of proven productivity.
Die Inserts: A removable, steel, serrated piece that fits into the jaws of tongs. Die inserts grip drill pipes, drill collars and casing while the tongs are making up or breaking out pipe.
Dies: A tool used to shape, form, or finish other tools or pieces of metal.
Diesel Engine: An internal-combustion engine frequently used for powering drilling rigs. A diesel engine is a high-compression engine that draws air into its cylinders and compresses the air to very high pressures; ignition then occurs as fuel is injected into the compressed, hot air. Combustion takes place in the cylinder above the piston; the combustion then powers the piston.
Dipmeter Survey: Also called a dip meter or dip log, this surveying method determines the direction and angle of a formation dip in relation to the borehole to provide geological structure of the formation.
Directional Drilling: Drilling in the opposite direction of a wellbore from the vertical. Directional drilling uses rotary steerable tools to move around rocks or other obstructions to continue drilling.
Division Order: A document used to describe the property owner’s interests in drilling operations to the property operator. The Division Order also details the owner’s personal information like their tax ID.
Downstream: The industry that includes: oil refineries, petrochemical plants, petroleum products distributors, retail outlets and natural gas distribution companies. The Downstream operates anywhere oil, plastics and natural gases are used.
Drill Bit: The cutting or boring element used to access oil or gas in the drilling process. Not only are most bits roller-cone bits, but the drill bit also typically includes both the cutting element and the circulating element.
Drill Collars: A heavy steel tube that’s placed between the drill pipe and the bit in the drill stem. Drill collars are used to add weight to the bit to make drilling easier.
Drill Pipe: A piece of seamless tubing used to rotate the bit and circulate the drilling fluid. The pipe joints are usually about 30 feet long and are joined together by tool joints.
Drill Rig: The machinery that’s used to drill oil and gas wells. There are two types of drill rigs: rotary and cable tools, with rotary drill rigs being more efficient.
Drill String: Transmits fluid and rotational power from the kelly bushing to the drilling collar. As the name suggests, the drill string is a column, or string, with attached tool joints.
Dry Gas: Natural gas composed mainly of methane with only minor amounts of ethane, propane and butane and little or no heavier hydrocarbons in the gasoline range.
Dry Hole: Describes a well that does not produce oil or gas at commercial volume; typically is a producing well, but does not have enough resources to justify production.
E #
E&A: Abbreviation for exploration and appraisal.
E&P: Abbreviation for exploration and production.
Electronic Flow Meter: Monitors the amount of oil and gas flowing from a wellhead; measurements are expressed in real time, actual flow, cumulative flow, and historical data.
Electronic Log: Used by geologists to determine the nature of rocks, a special tool is used in an uncased hole that outputs electrical current into the rock and records the rock’s resistance.
Electronic Rig: A drilling rig – typically powered by diesel – where the original energy source is converted to electricity via generators. Electricity is then pumped through electrical conductors to electrical motors.
Elevator Links: Cylindrical bars used to attach elevators to the hooks and support the weight of the elevator.
Elevators: Hinged steel devices with manual operating handles that are attached to rotary and top drive rigs. Crew members latch elevators onto tool joints to operate them.
Enhanced Oil Recovery: This oil recovery process that restores formation pressure and improves oil displacement can be used at any point of the productive life of an oil reservoir. There are three major types of enhanced oil recovery: chemical flooding, miscible displacement, and thermal recovery. Each recovery type alters the original properties of oil, but the specific type used is dependent on the temperature, depth, and other traits of the reservoir.
Estimated Ultimate Recovery (EUR): An estimation of the cumulative volume of reserves that will be discovered in a specific reservoir.
Exploration Drilling: Drilling carried out to determine whether hydrocarbons are present in a particular area or structure.
Exploration Phase: The phase of operations which covers the search for oil or gas by carrying out detailed geological and geophysical surveys followed up where appropriate by exploratory drilling.
Exploratory Well: A well created for the purpose of finding oil or gas in a previously unproductive area.
F #
Farm In: When a company acquires an interest in a block by taking over all or part of the financial commitment for drilling an exploration well.
Field: Used to describe the area holding reservoirs grouped on the same geological structural feature or stratigraphic condition. Can also describe the area holding a single reservoir.
Fishing: Retrieving objects from the borehole, such as a broken drill string, or tools.
Flowing Well: A well that produces oil and gas using its own reservoir pressure as opposed to pumps or other production methods.
Fluid Injection: Forces oil into producing wells by injecting gas and liquids into the reservoir.
Foamy Oil: Also known as heavy oil, this substance contains dispersed gas bubbles that were created at the wellhead of a heavy oil reservoir. The bubbles in foamy oil stay small, keeping the oil viscosity low, while still creating the energy needed to drive the oil to the producing well.
Formation Pressure: The pressure at the bottom of a well when it is shut in at the wellhead.
Formation Water: Salt water underlying gas and oil in the formation.
Fracturing: The process of a fluid (usually crude oil, diesel or water) being pumped into the reservoir to break the reservoir rock open.
Fracturing Fluid: A liquid, typically water, oil, or an acid, that’s used in hydraulic fracturing. Fracturing fluid assists in the hydraulic fracturing process by carrying propping agents that hold open formation cracks after hydraulic pressure dissipates.
Free Water Knockout (FWKO): A vertical or horizontal separator used to separate gas, oil and water. The water is removed to prevent corrosion and the formation of hydrates or tight emulsions.
G #
G: Gas.
G/C: Gas Condensate.
Gas Anchor: Used to prevent gas lock, this tubular and perforated device works by allowing the lighter gas to rise, while the fluids make their way to the pump. It works like this: fluids first enter the anchor, while gas rises and exits the anchor through the perforations at the top. The rest of the fluids enter the anchor through a mosquito bill which allows all the gas to escape before fluids enter the pump.
Gas Drive: The energy created by expanding compressed gas within a reservoir. Also called a depletion drive, this energy moves crude oil to a wellbore.
Gas Injection: The process of injecting gas into a reservoir to maintain the pressure created by the gas drive. This process also reduces the decline rate of the original reservoir drive. There are two main types of gas injection: non-miscible oil and miscible oil injection.
Gas Oil Contact: Used to describe the surface where the above gas and below oil make contact. This contact is transitional, forming a mix of gas and oil.
Gas/Oil Ratio: In well testing this refers to the ratio of produced gas to produced oil (also known as GOR); in production, this is the volume ratio of gas vs. oil that comes out of solution at standard conditions.
Gas Well: A well that primarily produces gas.
Geographic Information Systems(GIS): A computer system capable of assembling, storing, manipulating, and displaying geographically referenced information.
Grantee: The person who received the land or mineral grant.
Grantor: The person responsible for granting or conveying land, minerals, and other resources.
Gravity: Developed by the American Petroleum Institute, this standard measures the density of liquid as expressed by degrees. The lower the degree, the heavier the liquid.
Greasing Out: The massing our grouping of mud particles that occurs when the barite (cement aggregate) becomes coated with an oily substance.
Gunk Plug: Bentonite, cement or polymers mixed into an oil that is pumped into a well to seal a leak zone.
H #
Heavy Oil: Crude oil with an API gravity of 20 degrees or less. It tends to have a high viscosity and hinders an easy flow of oil.
High Pressure Control Valve: As the name suggests, the high pressure control valve is used to control fluids up to pressures of 6000 psig. The valves range from 2 to 10 inches long and are used to release fluid from areas of natural gas production.
Horizontal Drilling: A drilling technique that consists of vertical drilling down to a particular depth, and then involves turning at a right angle to drill horizontally within a specified reservoir.
Horizontal Severance: Reserves oil, mineral, or gas rights at specific geologic depths.
Hot Oiling: Hot oiling is used to dissolve or move paraffin deposits from production tubing by circulating heated oil.
Hydraulic: Operated, moved, or effected by water or liquid.
Hydraulic Fluid: A low-viscosity fluid used in a liquid-based system.
Hydraulic Fracturing: High-pressured liquid is pumped into a formation to force the formation open and create passages for oil to flow into the wellbore.
Hydraulic Pumping: A pumping method that uses a downhole pump without sucker rods. Specifically, two reciprocating hydraulic pumps are used; the first pump powers the second, production pump. Single and double tubing strings can both be used to pump multiple wells from a main source. When a single string is used, power oil travels down the string to the pump, and a mix of power oil and fluid is returned through the casing tub annulus. When two strings are used, power oil travels down one string, while the other returns the exhaust and produced fluid.
Hydrocarbon: A compound containing only the elements hydrogen and carbon. May exist as a solid, a liquid or a gas. The term is mainly used in a catch-all sense for oil, gas and condensate.
I #
Improved Oil Recovery: Generally speaking, improved oil recovery is any activity that increases oil production and recovery factor. However, in the restricted sense, it’s a process (like water flooding or gas flooding) that adds energy to the reservoir to increase oil production and recovery factor. Improved oil recovery allows further oil extraction beyond typical methods.
Induction Log: In this electric well log, the conductivity of a formation is measured. In other surveys, the resistivity is measured. Conductivity measurements work because oil-bearing formations are less conductive than water-bearing formations.
Injection Head: Injects coiled tubing into a well to seal the tubing and provide a pressure tight connection.
Injection Well: As the name hints, an injection well is a well where fluids are injected into an underground stratum. Also called an input well, this process increases reservoir pressure and displaces oil.
Intangible Drilling Costs: Abbreviated as IDC, these costs are inclusive of everything needed to drill and prepare wells for oil and gas production. Includes costs associated with ground clearing, construction of derricks and pipelines, and wages, among a plethora of other costs.
Interface Float: A weighted float created to sink in oil and float in water; used as a testing tool.
J #
Jacket: The lower section, or “legs”, of an offshore platform.
Joint: A single section of drill pipe, casing or tubing that’s usually about 30 feet long.
Joint Operating Agreement (JOA): A written agreement between multiple land operating partners that details how the land will be developed, who will pay for the exploration and development, and when this development will happen.
Joint Venture: A phrase to describe an oil and gas investment project.
K #
Kelly: This steel piece turns the drill stem as the rotary table turns; typically suspended from the swivel through the rotary table and then connected to the top joint of the drill pipe.
Kelly Bushing: A long hollow steel bar that’s used to connect the upper end of a drill string. Kelly bushing is a sleeve in the rotary table that allows the Kelly to freely move up and down during drilling. Kelly bushing also plays a part in the measurement of well depth, as well depth is measured from the Kelly bushing, down to the bottom of the well.
Kick: Occurs when water, gas, oil, or other fluid enters the wellbore during drilling when the pressure created by the column of drilling fluid is lower in comparison to the pressure created by fluids in the drilled formation. When not addressed, kicks may cause blowouts.
Kick Fluids: Any combination of fluids (including oil, gas, and water) that enters the borehole from a permeable formation.
L #
Landman: The person who manages land leasing and land damages for oil and gas companies.
Landowner: The individual who owns the property where minerals are found. Oftentimes the ownership is limited to the ground-level of the property.
Lay Barge: A barge that is specially equipped to lay submarine pipelines.
Lease: The agreement formed by the owner of the property and the interested exploration and development party. The property owner gives the lessee exclusive rights to search for and extract any minerals found on the property.
Lessee: The person who acquires the rights to drill for oil or gas on a piece of land.
Lessor: The landowner who grants access for drilling for oil or gas on their land, known as a mineral lease. The person who acquires the rights to drill for oil or gas on a piece of land.
Liner: The most common definition of a liner is a pipe used below existing casing to case an open hole. A liner extends from the setting depth up into another string of casing above the lower end of the oil string. Other types of liners include: a short type of perforated pipe that’s placed opposite of a producing formation to prevent loose sand from entering the well; liners in jet perforating guns are conically shaped and are used to increase the efficiency of the charge by improving the jet penetrability; cylinder liners are replaceable tubes created to fit inside the cylinder of an engine or a pump.
Liquefied Natural Gas (LNG): Oilfield or naturally occurring gas, chiefly methane, liquefied for transportation.
Liquefied Petroleum Gas (LPG): Light hydrocarbon material, gaseous at atmospheric temperature and pressure, held in the liquid state by pressure to facilitate storage, transport and handling. Commercial liquefied gas consists essentially of either propane or butane, or mixtures thereof.
Low Pressure Control Valve: A diaphragm used to control the flow of liquid and gas; often found in oil and water dump valves. Used in systems with working pressures up to 300 psig.
M #
Master Valve: Also known as the master gate, the master valve is located on the Christmas tree and used to control gas and oil flow.
MBOE: The acronym that represents one thousand barrels of oil equivalent.
Mechanical Oil Valve: Also known as a Mechanical Liquid Valve or a Dump Valve, it is designed to work together with a trunnion assembly to remove liquids from the vessel. It’s controlled by a mechanical level.
Mechanical Integrity Test: The act of setting a packer or retrievable bridge plug above the perforations in a wellbore and applying pressure to the annulus in order to ensure soundness of the casing.
Metric Ton (tonne): Equivalent to 1000 kilos, 2204.61 lbs.; 7.5 barrels.
Midstream Sector: The sector within the industry between oil production and the consumers that processes, stores and markets crude oil and natural gas.
Migration: The movement of oil and gas within layers of rock deep within the earth.
Mineral Rights: The owner of the gas, oil, or other minerals when they’re naturally occurring in a reservoir. Frequently, mineral owners will contract a oil or gas lease with a third-party to extract the minerals.
MMBBL: A unit of measurement to describe a million barrels of crude oil, bitumen, natural gas liquids, or condensate.
Moonpool: An aperture in the center of a drillship or semi-submersible drilling rig, through which drilling and diving operations can be conducted.
MOU/MOA: Memorandum of Understanding/Agreement
Mud: A mixture of base substance and additives used to lubricate the drill bit and to counteract the natural pressure of the formation.
N #
Natural Gas: A mixture of hydrocarbons and non-hydrocarbons (like Hydrogen Sulfide or Nitrogen) in the same gaseous space or in a mixture of crude oil in underground preserves.
Natural Gas Liquids (NGL): Liquid hydrocarbons found in association with natural gas.
Natural Gas Policy Act Of 1978: Enacted on November 9, 1978 and became effective December 1, 1978. The Act has been amended, and it replaced or amended the Natural Gas Act. Refer to 15USC 3301-3432.
Net Oil Production: The amount of oil produced minus the injected oil (also known as the power oil).
Non-Associated Gas: The extracted natural gas from a reservoir that doesn’t contain notable amounts of crude oil.
O #
Oil and Gas Lease: A contract between the mineral owner and the company interested in drilling that gives the interested company rights to explore and produce oil and gas for a specified term. The lease is usually given for royalty payments in return.
Oil-Base Mud: A type of drilling mud where the oil is in the continuous phase. Oil-base mud is frequently used where it is difficult to drill with waterbase mud.
Oil Chamber: A compartment of the separator that gathers oil skimming over the oil weir.
Oilfield: The surface area, reservoir, wells and production equipment overlying oil reservoirs.
Oil Outlet: The pipe that directs oil out of the treater.
Oil Weir: Similar to a dam, this vessel compartment allows oil to skim over into the oil chamber.
Operating Expenses: Any costs associated with operating a well or similar venture.
Operator: The party or person responsible for the drilling and operation of a well, and the maintenance of the leased land. All of the operator’s responsibilities will be detailed in the JOA.
Over Balanced Drilling: Used to describe instances where the pressure used to drill (from the drilling fluids) is more than the pressure of the oil or gas within the reservoir.
P #
Paid-Up Lease: An oil and gas lease that’s paid to the Lessor through the first term at the lease signing.
Payzone: Rock in which oil and gas are found in exploitable quantities.
Paraffin Base Crude Oil: Used for motor oil or kerosene, this crude oil contains a lot of paraffin wax, but minimal asphaltic materials.
Permeability: The property of a formation which quantifies the flow of a fluid through the pore spaces and into the wellbore.
Petroleum: A generic name for hydrocarbons, including crude oil, natural gas liquids, natural gas and their products.
Pipe: A hollow steel tube that transports fluids. Pipes used in oil fields are: casing, drill pipes, tubing, and line pipes.
Pipeline Oil: A type of oil acceptable for pipeline shipment because it’s free water, sediment, and emulsion (BS&W) content is low enough.
Platform: An offshore structure that is permanently fixed to the seabed.
Plunger: The part of the sucker rod pump that pulls well fluids into the pump.
Porosity: The percentage of void in a porous rock compared to the solid formation.
Possible Reserves: Those reserves which at present cannot be regarded as ‘probable’ but are estimated to have a significant but less than 50% chance of being technically and economically producible.
Power Oil: This type of crude oil is used to energize the bottom pump in hydraulic pumping through surface pressurization.
Primary Recovery: Recovery of oil or gas from a reservoir purely by using the natural pressure in the reservoir to force the oil or gas out.
Probable Reserves: Those reserves which are not yet proven but which are estimated to have a better than 50% chance of being technically and economically producible.
Production: Term used to describe the process of extracting, preparing, storing, and delivering well oils.
Profit Oil: After deducting the expenses from the oil production, the amount of production that’s left is known as profit oil. This oil will be shared among participating parties and the host government based on the production sharing contract.
Proven Field: An oil and/or gas field whose physical extent and estimated reserves have been determined.
Proven Reserves: Those reserves which on the available evidence are virtually certain to be technically and economically producible (i.e. having a better than 90% chance of being produced).
R #
Recomplete: An operation 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 zone.
Recoverable Reserves: That proportion of the oil and/gas in a reservoir that can be removed using currently available techniques.
Recovery Factor: That proportion of the oil and/gas in a reservoir that can be removed using currently available techniques.
Reenter: To enter a previously abandoned well.
Refinery: Processing plant where crude oil is turned into a variety of more useful oils like gasoline and diesel.
Reserves: The amount of oil and gas in a reservoir that can be extracted. Measured in terms of barrels of oil or million cubic feet (MCF)
Reservoir: Simply put, a reservoir is the rock body in which oil or gas is stored. Common reservoir rocks are limestones, dolomites, or sandstones – all rocks that are porous, permeable, or naturally fractured. A reservoir can be filled with oil, volatile oil, dry gas, and gas condensate.
Residual Oil: When fluids are flowing through rock by way of primary recovery, secondary recovery, and invasion, residual oil does not move.
Riser (drilling): A pipe between a seabed BOP and a floating drilling rig.
Riser (production): The section of pipework that joins a seabed wellhead to the Christmas tree.
Rotary: The machine used to drive rotational power to the drill stem while still allowing vertical movement of the pipe for rotary drilling. Most modem rotary machines have a rotary or master brushing used to turn the Kelly bushing, which then allows vertical movement of the Kelly while the stem is turning.
Roughneck: Drill crew members who work on the derrick floor, screwing together the sections of drill pipe when running or pulling a drill string.
Roustabout: Drill crew members who handle the loading and unloading of equipment and assist in general operations around the rig.
Royalty: A percentage of the profits made from the development of mineral resources. Royalties are paid to the property owners.
Royalty Revenue: Funds given to the lessor from the production of oil and gas excluding production costs, taxes, and transportation fees.
S #
Salt Water Disposal Well: Oilfield salt water is drained into these wells.
Secondary Recovery: Once a reservoir has been fully extracted using the primary production method, the well or field moves into secondary recovery. Secondary recovery methods frequently include gas injection or water flooding – the goal being to repressurize the reservoir for additional oil recovery.
Shut In: Closing the valves on a well to stop production. Can also refer to a well on which the valves were closed to stop production.
Shutdown: A production hiatus during which the platform ceases to produce while essential maintenance work is undertaken.
SI/TA: Shut In /Temporarily Abandoned
Sidetrack: A wellbore segment extending from a wellbore intersection along a wellbore path to a different wellbore bottom hole from any previously existing wellbore bottom holes.
Sidetracking: The well activity of drilling a new wellbore segment from a wellbore intersection to a new wellbore bottom hole or target.
Spring Loaded Back Pressure Regulator: Controls the gas pressure and water level in the vessel of a free water knockout.
Spud-In: The operation of drilling the first part of a new well.
Steam Oil Ratio: Also known as SOR, steam-oil ratio is used to rate the efficiency of steam injection oil production. The ratio measures the volume of steam needed to create one unit volume of oil and the lower the ratio, the more efficiently the steam is being used.
Surface Location: The location of a well or facility/measurement point.
Surface Reclamation: A restoration of the surface as for productivity or usefulness.
Suspended Well: A well that has been capped off temporarily.
T #
TCF: Trillion Cubic Feet (of gas).
Temporarily Abandoned: The act of isolating the completed interval or intervals within a wellbore from the surface by means of a cement retainer, cast iron bridge plug, cement plug, tubing and packer with tubing plug, or any combination thereof.
Tertiary Recovery: A type of improved recovery method used to restore formation pressure, improve oil displacement, or improve reservoir fluid flow. Can also be used to extract additional oil after the secondary recovery.
Toolpusher: Second-in-command of a drilling crew under the drilling superintendent. Responsible for the day-to-day running of the rig and for ensuring that all the necessary equipment is available.
Topsides: The superstructure of a platform.
Treater Valve: A floatless level control valve, typically installed with the water leg and oil leg of a heater treater.
Tubing: A pipe with a small diameter or a tube threaded at both ends. Tubing is lowered into a completed well so that oil and gas can be produced through the string of tubing.
Turnkey: A type of fixed price drilling contract where a drilling contractor is required to drill to a specific depth and provide ample equipment so the operator only needs to turn a valve to see oil or gas flow.
Two-Phase Separator: A horizontal, vertical, or spherical vessel that separates well fluids into gas and total liquid. The oil leaves the vessel through the bottom, while gas leaves through the top.
U #
UIC: Underground Injection Control
Ultra Heavy Oil: The US Department of Energy classifies a hydrocarbon fluid as an ultra heavy oil when it has a gravity of 10 degrees API or lower.
Unconsolidated Sandstone: A type of sand formation where the grains of sand don’t stick to each other. When an unconsolidated sandstone produces oil, it frequently is mixed with sand unless properly controlled.
Underground Injection Control: A program required in each state by a provision of the Safe Drinking Water Act (SDWA) for the regulation of Injection Wells, including a permit system. An applicant must demonstrate that the well has no reasonable chance of adversely affecting the quality of an underground source of drinking water before a permit is issued.
Unit Operator: When multiple oil companies are involved in field production, the unit operator is the company in charge of development and production.
Upstream Sector: The sector within the oil and gas industry that finds and produces crude oil and natural gas; often called the exploration sector.
V #
Valve: Used as a safety device to control flow within a line by opening or shutting a line completely.
Velocity: In geophysics, velocity is described as medium-distance divided by travel time. Velocity can be measured vertically, laterally, and azimuthally and measured with laboratory measurements, acoustic logs, vertical seismic profiles, and velocity analysis of seismic data.
Viscosity: Used to describe a fluid’s resistance to flow. For example, a highly viscous fluid won’t flow as easily as one with a low viscosity.
Viscous Oil: A heavy crude oil with a viscosity above 10 cp, a gravity below 22.3 degrees API, and low hydrogen-to-carbon ratios. Viscous oil also boasts higher acid numbers as well as high nitrogen and heavy-metal content.
W #
Water Drive: The production of oil due to the expansion of underlying water and rock, which then forces oil into the wellbore. Both bottom water drive and edge water drive are commonly used. Bottom water involves oil that’s totally in contact with water, whereas with edge water, only a small portion of the oil touches water.
Water in Oil Emulsion: A type of drilling fluid that consists of an external phase of oil with water or brine droplets.
Water/Oil Ratio: Also knowns as WOR, water oil ratio is the ratio of produced water to produced oil.
Well Log: A record of geological formation penetrated during drilling, including technical details of the operation.
Wildcat Well: A well drilled in an unproven area. Also known as an “exploration well”. [The term comes from exploration wells in West Texas in the 1920s. Wildcats were abundant in the locality, and those unlucky enough to be shot were hung from oil derricks.]
Workover: Remedial work to the equipment within a well, the well pipework, or relating to attempts to increase the rate of flow.
