Arrow Bowen Pipeline
The proposed Arrow Bowen Pipeline (ABP) will transport coal seam gas (CSG) from the Bowen Basin in central Queensland to a gas hub 22km north-west of Gladstone. The high-pressure steel pipeline will be buried at a minimum depth of 750mm in a 40m easement.
Australian Pipelines and Gas Association statistics show there are more than 33,000km of high-pressure steel pipelines in Australia, of which more than 25,000km are used for natural gas transmission.
Arrow will follow oil and gas industry best practice construction on the ABP. In particular, the pipeline will fully meet Australian Standard AS2885 - Pipelines Gas and Liquid Petroleum. This provides the standards for the design, construction, testing, operations and monitoring of high-pressure pipelines.
Pipeline construction process
Once the pipeline route has been finalised, Survey crews will survey and peg the exact route. It will be built within a 40m wide construction right of way (ROW).
Prepare access tracks
Temporary tracks will be constructed to provide regular access between existing road infrastructure and the ROW.
Clear and grade
Existing fences will be replaced by gates along the ROW.The ROW will be cleared, vegetation stockpiled for rehabilitation, and the ROW leveled (graded).
Stringing and bending
In a process known as stringing, the coated pipe will be transported to the site in 18m lengths and unloaded along the ROW. The pipe will be held off the ground on sandbags to prevent damage. The pipe can be bent using specialised equipment to match changes in the terrain or route.
Construction crews will weld the pipe together, allowing for any agreed stock and landholder access breaks.
Each weld is inspected to ensure it meets Australian Standards.
Weld joint coating
Joints will then be grit blasted and an external coating will be applied to prevent corrosion.
Using a wheel trencher, rocksaw or excavator (or a combination), a trench will be excavated to a depth of approximately two metres. Breaks in the trench will be left for any agreed stock and wildlife crossings, traffic and drainage.
Lowering and padding
Sideboom tractors are used to lower the welded pipe into the trench. As the pipeline is lowered into the ground the coating is tested for defects. Padding (fine sieved material) will be placed below and around the pipeline to prevent future coating damage.
A tie-in is performed when two lowered pipe strings are welded together in the trench.
The trench will be backfilled and compacted with the original subsoil and topsoil.
Hydrostatic pressure testing
The integrity of the pipeline is further verified using hydrostatic pressure testing. Sections of the pipeline are capped and water is pumped in at a pressure higher than the maximum allowable operating gas pressure.
As a safety measure and
in-line with Australian Standards, signage is erected above ground to warn people of the location of the buried pipeline.
The ROW will be restored and rehabilitated using stable landforms to re-establish topographic contours, reinstating natural drainage patterns and restoring fences. Temporary access tracks will also be restored.
Working with landholders
Arrow recognises every property is unique and works closely with each landholder to ensure our work practices take account of existing land and agricultural activities.
Arrow undertakes extensive research to optimise the pipeline route. Once a private property has been identified as a possible site of interest, the landholder will be contacted by an Arrow Land Liaison Officer (LLO) who will be the primary point of contact for the landholder.
The LLO works with the landholder throughout the entire process from agreeing the pipeline route, site access requirements and conditions of entry, to planning construction activities and rehabilitating the site.
Land access rules
Arrow has 12 Land Access Rules which set a high standard of behaviour for our staff and contractors as they work on private property. Rule breaches bring disciplinary action, dismissal or termination of contract.
Under the Petroleum and Gas Production and Safety Act 2004, Arrow must apply for various types of Petroleum and Gas Authorities at different stages:
- Authority to Prospect (ATP) – used for exploration activities
- Petroleum Lease (PL) – used for the development and commercialisation of proven gas reserves
- Pipeline Survey Licence (PSL) – used to survey the proposed route of a pipeline.
- Petroleum Pipeline Licence (PPL) – used for the construction and operation of pipelines.
This legislation sets out the rights and obligations of Arrow and landholders for exploring, producing and transporting gas and the land on which it is located.
The engagement process
Arrow applies an engagement process before, during and after pipeline-related works on a private property.
1.Pipeline route selection and landholder agreement
Each landholder is consulted on the viability of the proposed pipeline route and preferred alignment on their property.
The landholder is then asked to 'agree in principle' to the preferred alignment on their property, which will form the basis of all future discussions.
This allows engineering and design functions to proceed with certainty when carrying out the front end engineering and design work for the pipeline.
Access to private and public land is necessary to gather data for pipeline route and design purposes, as well as to fulfil pipeline licensing and environmental impact statement (EIS) requirements.
Access conditions are agreed with landholders.
The agreed pipeline route forms the basis of the 40m wide easement in which the pipeline will be located.
Third party valuers determine the market value of the easement area on the landholder's property. This figure then forms the basis of the purchase price of the easement that Arrow will pay to the landholder.
4.Easement terms and conditions
Easement terms and conditions are developed using an agreement for easement (AFE) document. Each AFE covers the items each party must legally commit to in relation to the registered easement.
5.Consequential loss and disturbance
A compensation framework forms the basis of compensation with landholders for any loss or damage experienced during pipeline construction. Generally, loss cannot be accurately determined until the construction stage, however agreement on the formula to be used, an indicative figure and terms and conditions can be reached in advance.
Arrow Land Liaison Officers (LLOs) will work closely with landholders during the pipeline construction. The compensation framework will form the basis of managing relationships and negotiating variations to compensation in response to any unforeseen circumstances or events during construction.
The easement area will be restored and rehabilitated as close as possible to its previous state using stable landforms to re-establish topographic contours, natural drainage patterns and fences. Rehabilitation of the easement area will primarily be determined by environmental conditions, however the landholder will also be engaged in the process.
Conditions for long-term access to the pipeline easement will be negotiated as part of the AFE
in stage four of this engagement process.