96 Karoon Gas Australia Ltd  Annual Report 2011 Term  Definition Operator One joint venture participant that has been appointed to carry out all operations on behalf of all the joint  venture participants. ordinary shares The ordinary shares in the capital of Karoon Gas Australia Ltd. ORR Over-riding royalty. p.a. Per annum. permit A hydrocarbon tenement, lease, licence, concession or Block. Petrobras Petróleo Brasileiro SA. play A trend within a prospective basin that has common geologic elements containing one or more fields,  prospects or leads with common characteristics. previous financial year Financial year ended 30 June 2010. prospect A geological or geophysical anomaly that has been surveyed and defined, usually by seismic data, to  the degree that its configuration is fairly well established, and on which further exploration such as  drilling can be recommended. prospectivity Referring to the likelihood of finding commercial hydrocarbons. prospective resource The term used to describe undiscovered volumes in an exploration prospect yet to be drilled. psia Pounds per square inch absolute. REAL Brazilian currency. recoverable gas An estimated measure of the total amount of gas which could be brought to surface from a given  reservoir. In a good quality reservoir this is usually in the order of 70-80% of the estimated gas-in-place. reserves Quantities of economically recoverable hydrocarbons estimated to be present within a trap. reservoir A porous and permeable rock formation to store and transmit fluids such as hydrocarbons and water. rig The equipment needed for drilling a well. It includes the onshore and offshore vehicles, mobile  platforms or vessel on which the equipment is stored. risk Prospect risk or geologic risk is the assessed chance that the drilling of the prospect will be successful  in finding significant volumes of hydrocarbons. The risk is calculated by multiplying the chance of  success of each of the petroleum system elements involved in the prospect. seismic survey A type of geophysical survey where the travel times of artificially created seismic waves are measured  as they are reflected in a near vertical plane back to the surface from subsurface boundaries. This data  is typically used to determine the depths and form of stratigraphic units and in making subsurface  structural contour maps and ultimately in delineating prospective structures. spud To start drilling a new well. Talisman Talisman Oil & Gas (Australia) Pty Limited. TCF Trillion cubic feet (1,000,000,000,000 cubic feet). unrisked A risk value has not been applied to an estimate of hydrocarbon volume either in place or recoverable. USD United States dollars. WAZ  Wide Azimuth Seismic Data GLOSSARY OF TERMS CONTINUED