Appraisal Well or Appraisal Drilling

A well that is being drilled into a discovered hydrocarbon accumulation to further understand the extent and size of the accumulation – usually denoted by “name-2”, “name-3” etc.  

Appraisal wells can be drilled either before or after an accumulation has been developed. Appraisal wells can be abandoned after drilling or kept as future production wells.  An Appraisal Well usually has a chance of success greater than an Exploration Well but less than a Development Well.


Australian Dollars

Barrel or BBL or bbl

An oil field unit of volume.  One barrel at standard conditions equals 158.9 litres.

Bscf or Bcf (gas volume)

Billions of standard cubic feet of gas. Equivalent to 1,000,000,000 standard cubic feet (nine zeros).

Caliper Logg

a measurement of the diameter of a well.


Cash in bank accounts, term deposits and bank discounted bills of exchange that are held by the company. The most liquid of assets.

Development Well or Development Drilling

A well that is being drilled into a reasonably well defined hydrocarbon accumulation. – usually denoted by “name-2”, “name-3” etc.

Development Wells are usually planned to exploit an accumulation of known hydrocarbons. The well usually has a chance of success greater than an Appraisal Well. It is usually expected that after drilling a Development Well it will be kept and converted into a Production Well. As nothing is certain in oil field drilling, Development Wells have an element of appraisal and as such Development Wells may also be termed Appraisal/Development Wells.


earnings before interest, tax, depreciation, amortization and exploration. EBITDAX is an indicator of the raw earning power of the company – essentially net production revenue minus corporate costs.

Electric Logs

measure of the resistivity of rock formations down a well which leads to determination of the rock types.

Exploration Permit

This is the legal instrument that allows an oil company to hold tenure or title to an area of ground and to explore for hydrocarbons.

Cooper Energy holds Exploration Permits in Tunisia and Australia (see PELXXX). Once a commercial discovery has been made a portion of the Exploration Permit will usually be excised from the Exploration Permit and converted to a production area.

Exploration Well or Exploration Drilling

The first well that is drilled into a Prospect – usually denoted by “name-1”.

An exploration well is used to prove if hydrocarbons exist in a Prospect.


the rock record of any sedimentary environment, including both physical and organic characters.

Flow-Line or Pipe-line

A cylindrical fiberglass or steel pipe used to transport oil or gas to a sales point. Usually a flow-line goes from a well head to the facilities and a flow-line or pipe-line from the facilities to the sales point. The terms flow-line and pipe-line can be used interchangeably but a pipe-line is usually considered more substantial is size than a flow-line.

Franking Credits

In its simplest form it is corporation tax that has been paid to the Government of Australia but not yet given as a tax credit to investors via a dividend.

FY12 etc

Financial Year 2013. Cooper Energy’s financial year is from 1 July to 30 June.

Gas in Place (GIP or GIIP)

an estimated measure of the total amount of gas contained in a reservoir and, as such, a higher figure than Recoverable Gas. May also be termed Gas initially in place (GIIP) to describe the volume of gas that exists at initial discovery.


a term used in seismic interpretation to identify the signal reflected from a particular layer of rock.

Hydrocarbon Value Chain

The simple sequential flow of work activities from New Ventures to Exploration to Appraisal to Development to Production to Sales. Usually all projects in the oil and gas industry follow this route.

In-situ (in place)

refers to total oil or gas reserves contained in a reservoir in the ground as opposed to those reserves which may be recovered.

Joint Venture

a group of companies or individuals who share the cost and rewards of exploring for and producing oil or gas from a permit.


hexagonal or square pipe about 15m long attached to the top of the drill string and turned by the rotary table. It is used to transmit the twisting movement from the rotary machinery to the drill string and thus the bit.


sediments deposited in a lake environment.


Sediments deposited in a lake environment


An immature unpenetrated/undiscovered exploration target that is not yet ready for drilling. A Lead may be matured into a Prospect.

Marker crude

a commonly traded crude oil in a particular region that is used as a quality standard to price other crudes.

Market Capitalisation

On an undiluted basis it is defined as the number of issued shares multiplied by the share price – it is a measure of the value the market puts on a company.

On a fully diluted basis it is defined as the number of issued shares plus the number of options multiplied by the share price. The option price should ideally be at a price equal or less than the current share price to be included in a fully diluted basis but this is sometimes ignored.

MM (oil volume) or mm (gas flow)

An oil field abbreviation for millions. This can sometime be confusing because S.I. nomenclature uses capital M for millions.

Net Pay

the aggregate thickness of only those parts of the reservoir which contain and produce hydrocarbons.

Oil a mixture

of liquid hydrocarbons of different molecular weights.


a device (often rubber) which seals off a section of the well during testing.


Petroleum Exploration Licence as used in South Australia e.g. PEL92.

P50 (and P90, Mean, Expected and P10)

When probabilistic Monte Carlo type evaluations are adopted, this is a statistical confidence level for an estimate.

P50 is defined as 50% of estimates exceed the P50 estimate (and by definition, 50% of estimates are less than the P50 estimate). It is a good middle estimate. Mean and Expected (same level of measure just different names) usually lie about the P40-P30 levels in oil field evaluations and are therefore high estimates. P90 and P10 are low and high estimates respectively.

P90 means 90% of the estimates exceed the P90 estimate. It does not mean that the estimate has a 90% chance of occurring – that is a very different concept.
The central limit theorem indicates that the P50 estimate has more chance of occurring than the P90 and P10 estimates.


Petroleum Production Licence as used in South Australia e.g. PPL207. Once a commercial discovery has been made in a PEL the area of the discovery is excised out of the PEL and converted to a PPL.


The volume of oil that is produced at the facilities. Production should ideally be stated at standard and stabilised conditions but sometimes it can be stated at non-standard or non-stabilised conditions (i.e. the oil has not been fully stabilized and still contains some light hydrocarbon fractions or is at a pressure and temperature that is not standard conditions).

Production Sales

The volume of produced oil that has been sold to the buyer. Usually equal to Production minus fuel minus flare minus losses.

Production Well

An exploration, appraisal or development well that has successfully penetrated a hydrocarbon accumulation and has subsequently been prepared so that hydrocarbons can flow to the surface to be processed and sold.


A reasonably mature unpenetrated/undiscovered exploration target. Usually a Prospect is ready to drill but there is a maturity grey area between a Lead and a Prospect – the Prospect simply being more mature than a Lead.

Proved, Probable, Possible

In deterministic evaluations; These are maturity and existence classification categories for recoverable hydrocarbons. Proved is usually well conformable, Probable is part of the continuous accumulation and Possible may exist.

In probabilistic evaluations, These are uncertainty classification categories for recoverable hydrocarbons. Proved is usually defined as the P90 estimate for the whole discovered accumulation, Proved plus Probable is usually defined as the P50 estimate for the whole discovered accumulation and Proved plus Probable plus Possible is usually defined as the P10 estimate for the whole discovered accumulation.

Care should be taken not to compare deterministic definitions with probabilistic definitions as they are not equivalent measures of recoverable hydrocarbons. Further information on these categories can be found in the Recoverable Hydrocarbon Reporting Guidelines on Cooper Energy’s website (


Abbreviation of Production Sharing Contract. This is the title instrument that allows an oil company to hold tenure to an area of ground and defines the work program associated with the area and the oil company’s rights to any production or revenue. PSCs are used in many countries.

In Indonesia the PSC allows the oil company to explore for and produce hydrocarbons. Indonesia uses the PSC as the exploration and production instrument rather than issue separate exploration permits and production concessions.


a mineral composed of silicon dioxide.

Recoverable Oil Replacement Ratio

Defined as the amount of oil that has been added to the recoverable oil portfolio through the financial year divided by the amount of production. The ratio will be greater than one if more oil has been added to the portfolio than has been produced – the best result. A ratio greater than zero but less than one means that recoverable oil has been added to the portfolio but it is less than what was produced – an acceptable result. A ratio of zero means no recoverable oil has been added to the portfolio – not a good result.

It is possible to go negative if no oil has been discovered during the year and/or if studies revise downwards the previous recoverable oil estimate – the worst result.
Unless stated otherwise Cooper Energy usually states the ratio in relation to the Proved oil portfolio.

Reserves and Resources

They are simply both names for recoverable hydrocarbons. Depending upon the standard adopted.

Reserves are recoverable hydrocarbon estimates that are expected to be produced and sold in the future for economic gain. At a minimum, Reserves have usually been justified and approved for development.

Resources are also recoverable hydrocarbon estimates but they are usually less technically, commercially or economically mature than Reserves and usually have not been justified for development.

All recoverable hydrocarbons (and Reserves and Resources) need a descriptive prefix if the maturity, existence and uncertainty of the estimate is to be fully understood. i.e. Proved Reserves.

Further information on recoverable hydrocarbon categories can be found in the Recoverable Hydrocarbon Reporting Guidelines on Cooper Energy’s website (

Stabilised Conditions

"Fresh" oil from wells is often under pressure (naturally or pumped) and usually contains substantial dissolved gases. This oil needs to be "stabilised" prior to storage, shipment or refining so that is becomes a safer product to handle. This means depressurizing the oil, flashing off the gases and then running it through a process in order to set the oil to an agreed specification.

Standard Conditions

The benchmark pressure and temperature condition for measuring hydrocarbons in the petroleum industry – usually 60 °F (degrees Fahrenheit) and 14.7 psia (pounds per square inch absolute).

Sales Revenue

The Production Sales multiplied by the price that is received for each unit of sale i.e. 1 million barrels multiplied by US$100 per barrel equals US$100 million of revenue. Sales Revenue does not have deductions for operating costs or off-take costs.

Tscf or Tcf (gas volume)

Trillions of standard cubic feet of gas. Equivalent to 1,000,000,000,000 standard cubic feet (twelve zeros).


United states dollars.

Unloading Station

When oil is trucked the Unloading Station is the destination point where oil is pumped out of the truck.Trucks are filled up at the Loading Station at the oil facilities before driving off to the Unloading Station.

Working Capital

Current Assets minus Current Liabilities.

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