Production

Abandonment/Decommissioning

Process of dismantling wellhead, production and trans- portation facilities and restoration of depleted producing areas in accordance with licence requirements and/or legislation.

Acid stimulation

Form of hydrochloric acid is pumped down well hole to en- large pore space in oil bearing rocks to increase flow and reco- very.

Acoustic log

Record of time taken by a sound wave to travel over a certain distance through geological formations.

Air injection

An enhanced recovery technique in which air is injected into hydrocarbon formation to increase reservoir pressure.

Artificial lift

Any techniques, other than natural drives, for bringing oil to surface.

Blow-down

Condensate and gas produced simultaneously from outset of production.

Casing perforation

Holes made in liner of a finished well to allow hydrocarbons to flow into production tube.

Cathodic protection

Method used to minimise rate of electrochemical corrosion of structures, for example, installations offshore, pipelines and storage tanks.

Christmas tree

Branching series of pipes, gauges and valves on top end of each production well to control flow of oil or gas.

Closed-in

Descriptive of a well that is capable of producing, but is not currently producing.

Coiled tubing

Used to carry production equipment to bottom of well.

Commingling

Producing oil and gas from two or more reservoirs at different depths, or where product of two or more fields is transported via a common pipeline.

Delineation well

Drilled at a distance from a discovery well to determine physical extent, reserves and likely production rate of a new oil or gas field.

Deviated well

Horizontal well drilled at an angle (over 80 degrees) to vertical.

Development

Phase on which a proven oil or gas field is brought into production by drilling production (development) wells.

Development well

A production well drilled with intent of producing oil or gas from a proven field.

Dual Completion

A well completed to produce from two separate reservoirs.

Enhanced reach

Deviated wells (over 65 degrees) from vertical and reach out horizontally more than twice vertical depth.

Field

Geographical area under which an oil or gas reservoir lies.

Field Nomenclature

Field ceased production (FCP)

Field under development (FUD)

Field in production (FIP)

Flaring and venting

Flaring is burning of hydrocarbon gases for commercial or technical reasons. Venting is release of gases to atmosphere.

Flare Stack

Steel structure on an offshore installation or at a proces- sing facility from which gas is flared.

Gas Cap

In field containing both gas and oil, some gas will often collect at top of reservoir in a single deposit.

Gas/Condensate field

Reservoir containing both natural gas and oil, with greater proportion of gas. Condensate appears when gas is drawn from well, and its temperature and pressure change sufficiently for some of it to became liquid petroleum.

Gas field

Field containing natural gas, but no oil.

Gas gathering system

Central collection point for offshore gas fields. Production is then piped to central processing system onshore.

Gas Injection (GI)

Associated gas is pumped back into a reservoir to maintain reservoir pressure. In this way rate of production of crude oil also can be increased.

Gas lift

Gas from same or nearby field is mixed with oil in tubing to lessen weight of liquid column.

Gas Processing

Separation of oil and gas, and removal of impurities and NGLs from natural gas.

Gas Treatment

Removal of impurities, condensate, hydrogen sulphide and NGL_S from natural gas.

Gravity Structures

Either concrete or hybrid (concrete base and steel legs and superstructure) structures that due to weight rest on seabed or piled into it.

Horizontal well

Used when reservoir permeability is low or hydrocarbons are being produced from vertical fractures in rock.

Jacket

Supporting (concrete base or steel legs) structure for an offshore installation.

Marine Riser

Pipe connecting offshore installation to a subsea wellhead or pipeline for drilling or production purposes.

Module

Self-contained box or package built with a specific purpose (for example, well head, oil and gas separation, gas compression, platform power generation, mud, storage, diesel, filter and exhaust) located on production installations.

Multilateral well

More than one horizontal section drilled in one well. Used to maximise number of wells that can be drilled from small installations.

Odorant

Substance (for example mercaptan) added to odourless natural gas or NGLs to enable detection.

Offshore Oil Loading Nomenclature Single buoy mooring (SBM)

Single point mooring (SPM)

Exposed location single buoy mooring (ELSBM)

Spar

Enables offshore loading with vessel swinging to present least resistance to prevailing wind or current conditions.

Oil in Place (OIP)

Estimation of real amount of oil in a reservoir. Higher value than recoverable reserves of reservoir.

Pig

Device for cleaning a pipeline or separating two liquids being moved down pipeline. (Intelligent pig - fitted with sensors to check for corrosion or defects in pipelines.)

Piling

Long steel piles driven into the seabed to anchor fixed offshore structures solidly in place.

Pipeline

A pipe through which natural gas, crude oil or petroleum products are pumped between two points, either onshore or offshore.

Plateau

Level of peak oil or gas field production; it is always followed by declining level of production.

Platform

Fixed structure resting on seabed or piled into it. Platform Nomenclature

Tension Leg Platform (TLP)

Minimum Facility Platform (MINF)

Not Normally Attended Installation (NNAI)

Gravity based structures (GBS)

Accommodation (ACCOM)

Compression (COMP)

Drilling (DRIL)

Riser (RISE)

Preventative maintenance

Maintenance carried out prior to unit or system failure.

Primary Recovery

Recovery of hydrocarbons from a reservoir using only na- tural reservoir pressure.

Produced Water

Brines naturally present or injected into reservoir to enhance production. Produced along side oil production.

Production Drilling

Drilling of wells in order to bring a field into production.

Production Installation

An installation from which development wells are drilled and that carries all associated processing plants and other equipment needed to maintain a field in production.

Production String

Tubing or piping in a production well through which oil or gas flows from reservoir to wellhead.

Recovery Factor

Ratio of recoverable oil and / or gas to estimated oil and / or gas in place in reservoir. Determined by a various factors such as reservoir dimensions, pressure, nature of hydrocarbons, and development plan, (see also Primary, Secondary and Tertiary Recovery.)

Redetermination

Retroactive adjustment to relative percentage interests of joint venturers in a field.

Reserves: Possible

Reserves at present cannot be regarded as “probable”.

Reserves: Probable

Reserves not yet “proven”, but are estimated to have a better than 50% chance of being technically and economically producible.

Reserves: Proven

Reserves which on available evidence are virtually certain to be technically and economically producible.

Reservoir

Subsurface, porous, permeable rock formation in which hydrocarbons are present.

Reservoir drive

Powered by difference in pressures within reservoir and well.

Reservoir engineering model

Used to predict reservoir behaviour during production to enable selection of most efficient method of recovery.

Satellite Installation

An offshore structure that depends on another installation for materials or services.

Secondary Recovery

Recovery of hydrocarbons from a reservoir by increasing reservoir pressure by injecting gas or water into reservoir rock, (see also Primary and Tertiary Recovery.)

Slug catcher

Plant installed in a gas pipeline system to catch unwanted “slugs” of liquid.

Subsea manifolds

Allows wells to be put on production without need to build a platform to operate and maintain wells.

Sub-sea wellhead

A wellhead installed on the sea floor and controlled remotely from a platform, a floating production facility or land.

Substructure

Support form of an offshore installation on which derrick, engines, helicopter pad, cranes, etc. are installed.

Tension Leg Platform .

A floating offshore structure held in position by a number of tension-maintaining cables anchored to seabed. Cables dampen wave action to keep platform stationary.

Terminal

Onshore transit installation that receives oil or gas from offshore production facilities via pipeline and/or tankers. Plant and equipment designed to receive and process crude oil or gas to remove water and impurities.

Tertiary Recovery

Recovery of hydrocarbons from a reservoir by sophisticated methods, for example, heating reservoir or enlarging pore spaces using chemicals, (see also Primary and Secondary Recovery)

Tubing

Piping installed in wells for production of oil and gas.

Topsides

Top of an installation positioned on jacket.

Water Injection (WI)

Water is pumped into alternate wells in a field. Pressure in reservoir as à whole can be maintained or increased and production can be maintained or increased.

Well Nomenclature (Field)

Development (DEV)

Deviated (DEVW)

Gas Injection (GI)

Water Injection (WI).

Workover

Re-entry into a completed field well for modification or repair. Restoring well productivity by cleaning out accumulations of sand, silt or other substances that clog production tubing.