1C Low estimate of contingent resources.
1P Proven reserves.
2C Best estimate of contingent resources.
2P Proven and probable reserves.
Accelerated Development Programme  A 12-month programme focused on developing and equipping our next generation of leaders
APPEA Australian Petroleum Production and Exploration Association
Apprentice Programme A four-year programme with four streams: Process Technology, Fitting and Machining, Electrical and Mechanical trades
Australian Standard on Assurance Engagements 3000 Standard applied to assurance engagements other than audits or reviews of historical financial information
barrel/bbl The standard unit of measurement for all production and sales.
Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal  An international treaty designed to reduce the movements of hazardous waste between nations, specifically to prevent transfer of hazardous waste from developed to less developed countries
bcf/bscf Billion standard cubic feet, a measure of gas volume.
Biomass power A reliable base load power source generated by the combustion of organic materials; wood chips are favoured as a biomass fuel due to their low ash content and a relatively constant heating value 
Bio-remediation Waste management technique involving the use of organisms to remove or neutralise pollutants from a contaminated site
boe Barrels of oil equivalent - the factor used to convert volumes of different hydrocarbon production to barrels of oil equivalent. Conversion rate used by Oil Search for gas is 6,000 scf = 1 boe up to and including 2013 production; 5,100 scf = 1 boe thereafter.
bopd Barrels of oil per day.
BTU British Thermal Units, a measure of thermal energy.
CAP Competency Assurance Programme
CDP Carbon Disclosure Project
CDP Citizen Development Programme
CEIMS Crisis, Emergency and Incident Management System
CO2 -e/mmboe Carbon dioxide equivalent per million barrels of oil equivalent
CO2-e Carbon dioxide equivalent, a standard unit for measuring greenhouse gases
Community Area Planning (CAP) projects Community development projects where our materials and funding are combined with community contributions such as labour and land
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.
contingent resources The Company’s technically recoverable resources for its discovered but uncommercialised gas fields are classified as contingent resources. 2C denotes the best estimate of contingent resources.
COP 21  Held in Paris, the 2015 United Nations Climate Change Conference that was the 21st yearly session of the Conference of the Parties (COP) to the 1992 United Nations Framework Convention on Climate Change (UNFCCC); it was also the 11th session of the Conference of the Parties (CMP) to the 1997 Kyoto Protocol
crude oil Liquid petroleum as it comes out of the ground. Crude oils range from very light (high in gasoline) to very heavy (high in residual oils). Sour crude is high in sulphur content. Sweet crude is low in sulphur and therefore often more valuable.
development well Wells designed to produce hydrocarbons from a gas or oil field within a proven productive reservoir defined by exploration or appraisal drilling.
deviated well A well whose path has been intentionally diverted at an angle from vertical, often to reach a distant part of the reservoir and increase exposure to producing zones.
EBITDAX Earnings before interest, tax, depreciation, depletion, exploration and impairment.
EITI Multi-Stakeholder Group (MSG) Group of representatives from civil society, government and the private sector tasked with progressing EITI in their country
EITI Supporting Company    
Emissions intensity The ratio of carbon dioxide emitted relative to production
Employee Assistance Programme (EAP)  An externally provided, confidential counselling service for employees and their families
Endemic A plant or animal that is native or restricted to a certain area
ESG Environment, social and governance 
Extractive Industries Transparency Initiative (EITI)  Global standard that promotes open and accountable management of natural resources
FEED Front end engineering and design. Conceptual design prior to detailed design.
FID Final Investment Decision.
Forest Reference Level One of the elements to be developed by developing countries implementing REDD+ activities
Fossil fuel A naturally occurring and finite fuel such as coal or gas, formed in the geological past from the remains of living organisms
Gearing Net debt / (net debt & shareholders' funds).
Global Compact Network Australia (GCNA) The Australian chapter of the United Nations Global Compact
GOR Gas to oil ratio.
Graduate Development Programme A three-year programme that exposes graduate recruits to various parts of our Company; includes job placements, two residential programmes to develop personal and business leadership skills, and ongoing support and monitoring
Greenhouse gases Gases that contribute to the greenhouse effect by absorbing infrared radiation e.g. carbon dioxide and chlorofluorocarbons
GRI Global Reporting Initiative
High Potential Incident  Safety event with potential for one or more fatalities
Host communities Communities located in and around our areas of operation
HSS Committee  Board Health, Safety and Sustainability Committee
HSS Group 1  Senior management group responsible for reporting and evaluating material health, safety, environment, security and social responsibility issues and updating the Board HSS Committee
HSS Groups The mechanism by which all employees can provide input and feedback for HSS performance and initiatives
hydrocarbons Solid, liquid or gas compounds of the elements hydrogen and carbon.
Individual Career Development Plan A formal planning process that enables our employees to input into and agree on a skills and experience development plan that aligns with their future career objectives
Infrastructure Tax Credit Scheme (ITCS) A voluntary scheme in PNG whereby an agreed percentage of gross assessable income can be applied by companies to approved infrastructure construction and maintenance projects; the ITCS is for local projects and the NITCS for national projects
International Union for Conservation of Nature Red List of Threatened Species (IUCN Red List or Red Data List) The world's most comprehensive inventory of the global conservation status of biological species
IOGP International Association of Oil and Gas Producers
IPIECA International Petroleum Industry Environmental Conservation Association 
ISO 14001 International standard for environmental management systems
Karst limestone  Area made up of limestone, a soft rock that dissolves in water over time, creating caves and holes
Lanco PNG landowner company, formed by and representing local landowners
Landowner Benefits Identification Programme (LOBID) A process whereby the PNG Government identifies the beneficiaries of the PNG LNG Project
LNG Liquefied natural gas.
Local content The use of local employees and businesses
Local PNG suppliers Oil Search suppliers paid in PNG Kina
Lost Time Injuries (LTI) The sum of fatalities and Lost Work Day cases
Lost Work Day Case Any work-related injury, other than a fatal injury, which results in a person being unfit for work on any day after the day the occupational injury occurred; ‘any day’ includes rest days, weekend days, leave days, public holidays or days after ceasing employment
LPG Liquid petroleum gas.
LTI Long Term Incentive.
Major Accident Event (MAE) Low likelihood catastrophic event that can result in multiple fatalities and widespread environmental, economic and reputational damage
Marie Stopes PNG (MSPNG) A social enterprise, affiliated with Marie Stopes International, which delivers sexual and reproductive healthcare and family planning services to the underserved population of PNG
MENA Middle East/North Africa.
mmbbl Million barrels.
mmscf/d Million standard cubic feet per day.
MTPA Million tonnes per annum (LNG).
MW Megawatt, a unit of power equal to one million watts
Oil & Gas Act Primary legislation governing petroleum (including oil and gas) exploration and production in PNG
Operator Company or other legal entity that’s responsible for managing oil and gas exploration, development and production
Our Way Our management system: defines the vision, values, Company culture and behaviours expected of our people and the governance, procedure setting and Company-wide ways of working
Paris Agreement See COP 21
PDL Petroleum Development Licence.
PJ Petajoules – joules are the metric measurement unit for energy – a petajoule is equal to 1 joule x 10 15.
PL Pipeline Licence.
PNG Papua New Guinea.
PNG Business Coalition for Women Group of companies and corporate leaders driving positive change for women and businesses in PNG
PNG LNG Project Operator ExxonMobil PNG Limited, a subsidiary of Exxon Mobil Corporation (ExxonMobil).
PPFL Petroleum Processing Facilities Licence.
PPL Petroleum Prospecting Licence.
PPP Public-Private Partnership 
Precautionary approach  A risk management approach whereby a lack of full scientific certainty is not used as a reason for postponing cost-effective measures that will prevent environmental degradation if there are threats of serious or irreversible damage
PRL Petroleum Retention Licence.
probable reserves Probable reserves are those reserves which geological and engineering data demonstrate to be potentially recoverable, but where some element of risk or insufficient data prevent classification as proven. Probable reserves are calculated by subtracting proven reserves from those probabilistically calculated reserves having a 50 per cent confidence level (P50). Therefore, "Proven plus Probable" (2P) reserves are defined as those reserves which have a 50 per cent likelihood of being equalled or exceeded.
Process safety A framework for managing the integrity of operating systems by applying good design principles, engineering, and operating and maintenance practices; deals with the prevention and control of events with the potential to release hazardous materials and energy
Production Figure used when calculating our greenhouse gas emission intensity: includes all oil, gas from the Hides Gas Field and associated gas from oil operations, including that exported to the PNG LNG Project
proven reserves Proven reserves are the estimated quantities of crude oil, natural gas and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Proven reserves are limited to those quantities of oil and gas which can be expected, with little doubt, to be recoverable commercially at current prices and costs, under existing regulatory practices and with existing conventional equipment and operating methods. Proven (1P) reserves are probabilistically calculated reserves having a 90 per cent confidence level (P90); such reserves have a 90 per cent likelihood of being equalled or exceeded.
REDD+ An effort to create a financial value for the carbon stored in forests, offering incentives for developing countries to reduce emissions from forested lands and invest in low-carbon paths to sustainable development; the goal is to reduce emissions from deforestation and forest degradation, and foster conservation, sustainable management of forests and enhancement of forest carbon stocks
seismic survey A survey used to gain an understanding of rock formations beneath the earth’s surface.
Short-term incentive scheme A mechanism for rewarding employee performance whereby compensation is received for achieving the Company’s short-term business objectives
Social licence to operate The level of acceptance or approval continually granted to an organisation’s operations or project by local community and other stakeholders.
Social mapping and landowner identification A process whereby the Operator gathers information on the social make-up of a community, such as decision-making processes and land ownership, in accordance with the PNG Oil and Gas Act and submits it to the PNG Government
Stakeholders Groups of people inside and outside our Company that we can impact and that can impact, or have an influence on, our Company outcomes
STI Short Term Incentive.
Sustainable development Development that meets the needs of the present without compromising the ability of future generations to meet their own needs; includes community and local economic development and sustainable use of natural resources
Sustainable Development Goals United Nations goals for global sustainable development aimed at ending poverty, combatting climate change and fighting injustice and inequality by 2030
tcf Trillion cubic feet, a measure of gas volume.
Tier 1 and Tier 2 incidents See API RP 754 for a detailed definition. 
Total Recordable Injury Rate (TRIR) The total number of recordable injuries per million staff hours worked
United Nations Global Compact (UNGC) Voluntary business initiative based on CEO commitments to implement universal sustainability Principles around human rights, labour rights, anti-corruption and the environment
United Nations Guiding Principles for Business and Human Rights An authoritative global standard for preventing and addressing the risk of adverse human rights impacts linked to business activity
Valuer-General A division of the PNG Department of Lands and Physical Planning that’s responsible for setting land values
Village Liaison Committee (VLC) A committee comprising representatives from host communities that we form to help facilitate consultation, engagement, communication and cooperation
Village Liaison Officer (VLO) A host community representative we employ to facilitate communication between the community and our Company
VOCs Volatile organic compounds 
Voluntary Principles for Security & Human Rights A set of principles designed to guide companies in maintaining the safety and security of their operations within an operating framework that encourages respect for human rights
wildcats Exploration wells testing new play concepts or structures distanced from current fields.
Wildlife Management Area (WMA) Committee Committee of local community representatives that is responsible for managing the use of high-value natural areas in PNG