Glossary of terms
Appraisal (pilot) wells – Broadly speaking, there are three phases of coal seam gas operations: exploration, pilot testing and production. Exploration aims to identify gas bearing coals, and wells are generally widespread. If exploration indicates the potential for gas production, appraisal (pilot) wells may be drilled. A pilot test is essentially a small scale production trial, with associated water and gas handling facilities. If pilot testing indicates that commercial quantities of gas can be produced, full scale production may commence.
Borehole – This refers to a drilled hole or the wellbore itself, including the openhole or uncased portion of the well.
Central gas processing facility (CGPF) – The CGPF accepts gas from the surrounding gas fields and the facility processes low pressure coal seam gas into high pressure sales-quality gas.
Dam maintenance – To ensure dams remain in a safe and working condition, regular dam inspection, monitoring and maintenance is required. All maintenance work undertaken meets with applicable regulatory requirements.
Data logging – This activity is also called well logging or borehole logging, which includes taking a record of the geological formations penetrated by a borehole. This can be undertaken by lowering instruments into the borehole (geophysical logs) or by visual inspection of formation samples brought to the surface (geological logs).
Decommissioning – At the end of the working life of a facility, it is decommissioned and the inherent materials and machinery removed. For example, once a well is no longer required, production equipment is recovered and the well is sealed with cement. Once above ground infrastructure is removed, the area is rehabilitated to its original state.
Demobilising – Demobilisation involves the removal of equipment and tools, such as a drill rig from a well site.
Exploration wells – Broadly speaking, there are three phases of coal seam gas operations: exploration, pilot testing and production. Exploratory wells are drilled to verify the presence of a reservoir that contains gas, which if it is of sufficient volume, can lead to commercial production.
Field execution – This includes construction of plant or equipment such as building and installing pipelines, compression facilities and water processing facilities.
Flaring – Flaring is controlled burning of gas during start-up and some operational requirements. Read the Flaring fact sheet
Gathering lines – This refers to underground buried pipes that transport coal seam gas and water from the wellhead to gas processing facilities, storage tanks and water treatment facilities.
Geotechnical surveys – A survey designed to collect information on subsurface soil, rock, clay and/or sand prior to building plant and equipment, in order to establish correct foundation design. Read the Geotechnical Survey fact sheet.
Groundwater monitoring – Arrow’s water bore monitoring program provides critical data on groundwater to the Queensland Government and landholders. It creates an important reference point for ongoing monitoring and enables us to assess and manage potential groundwater impacts in the future. Read the Understanding Groundwater fact sheet.
Major pipelines – Major pipelines transport natural gas from processing facilities to gas-fired power stations or liquefied natural gas plants.
Mobilisation – Activities in the initial phase of setting up involves assembling, preparing and moving equipment and tools, such as a drill rig to a well site.
Production wells – There are three phases of coal seam gas operations: exploration, pilot testing and production. If pilot testing indicates that commercial quantities of gas can be produced, full scale production may commence. Watch the Coal seam gas and extraction video.
Seismic surveys – surveys designed to gather detailed images of the rock formations below the earth's surface. Sound waves are created by a vibrating pad that is mounted on a truck or buggy. The sound waves reflect off underground rock formations and are recorded for analysis. Read the Seismic Survey fact sheet.
Site assessment - cultural heritage – Arrow has cultural heritage legislative compliance requirements, which includes the development of Cultural Heritage Management Plans. As part of these legislative requirements, Arrow is required to minimise impacts and avoid harm to cultural heritage. Arrow will survey an area of interest to identify Indigenous and non-Indigenous sites and artefacts before any work commences.
Site assessment – ecology – As part of Arrow's environmental compliance requirements, Arrow must survey an area of interest to identify flora and fauna species and vegetation communities before any work commences. Knowledge of the on-ground biodiversity enables Arrow to avoid, minimise and mitigate potential impacts from our work.
Site assessment – land – a visual assessment of the land to confirm the site location(s) or alternate preferred location(s). A land assessment usually includes an ecology assessment and a cultural heritage assessment.
Site preparation – This involves activities necessary to prepare a site for upcoming activities. Site preparation involves clearing vegetation, removing top soil and putting down materials to reduce soil erosion and impacts from heavy machinery movement.
Site rehabilitation – This activity involves removing exploration and operational equipment facilities (e.g. compression facilities, well pads, pilot dams) and rehabilitating the surrounding area to its original state.
Well completion – Once a gas well is drilled, and it has been verified that commercially viable quantities of gas are present for extraction, the well must be ‘completed’ to allow for the flow of gas out of the formation and up to the surface (as a production well). This process includes strengthening the well hole with casing, evaluating the pressure and temperature of the formation, and then installing the proper equipment to ensure an efficient flow of gas out of the well.
Workover – When a well has been completed and has produced for a period of time, it must be maintained in response to changing conditions. Well workovers are undertaken to repair or perform maintenance which may involve the removal and replacement of down-hole equipment.