Pilliga Rehabilitation

Santos has spent much of 2012 and the first quarter of 2013 rehabilitating and upgrading a number of coal seam gas exploration sites in the Pilliga near Narrabri.

The sites were acquired in November 2011, when Santos took over the activities of Narrabri-based CSG explorer Eastern Star Gas (ESG).

The operations in the Pilliga were shut down in December 2011 and Santos began a thorough review of all existing sites.

Following this review, a detailed work program for the rehabilitation of sites in the Pilliga has been formulated. Extensive testing has been carried out and site specific rehabilitation plans prepared to ensure each site is successfully remediated. To-date, Santos has committed more than $17 million to remediation works and substantial progress has been made.

In November 2012, Santos announced that as part of its rehabilitation initiatives it was seeking Government approval to replace the existing water treatment facilities in the Pilliga with a new facility at Santos’ “Leewood” property outside the forest. Approval for the first stage of this facility was received in March 2013. More information here.

The Pilliga rehabilitation will take time and Santos is committed to ongoing monitoring of rehabilitation progress and responsible environmental management of its operations.

Below is progress of our rehabilitation work to-date.

Bibblewindi

Bibblewindi was the site of ESG’s water treatment facility. The facility comprised a reverse osmosis unit for the desalination of water extracted during CSG operations and water storage ponds.

In June 2011, prior to Santos’ takeover of ESG, approximately 10,000 litres of untreated saline water leaked from a pipe near the reverse osmosis plant at Bibblewindi. Santos has just received approval to construct stage one of a new central water treatment facility outside the Pilliga State Forest to manage and treat extracted water in the future.

Soil treatment trials were conducted at the site and a full rehabilitation plan developed and endorsed by the regulator.

Following the removal of dead vegetation, which was later used for soil stabilisation and habitat creation, civil works to treat the soil began in October 2012 and completed in March 2013.

A program of irrigation and revegetation is now being implemented and will continue throughout 2013.

Rehabilitation

March 2012

March 2013

January 2012

March 2013

 

Bibblewindi Water Treatment Plant

The water treatment plant was shut down by Santos in December 2011. A review of the facility found the reverse osmosis unit had a history of operational issues and the plant and ponds were not constructed to Santos standards.

An execution plan was prepared to properly decommission the Bibblewindi facility, and the removal of the plant began in October 2012 and completed in December 2012.

 

January 2012

March 2013

January 2012

March 2013

 

Bibblewindi Water Storage Ponds

The three storage ponds located at the Bibblewindi facility have been found unsuitable for long term use and were not constructed to Santos standards.

Substantial work was carried out in 2012 to stabilise the ponds and improve the condition of the pond banks. The decision to construct a new water storage facility outside the Forest means the ponds will eventually be removed and the site rehabilitated.

Water will remain in the Bibblewindi 3 pond until the new facility is completed. As an interim measure, additional monitoring bores have been installed around the ponds.

 

May 2012

Bibblewindi3May12_1

October 2012

Bibblewindi3Oct12_1

May 2012

Bibblewindi3May12_2

October 2012

Bibblewindi3Oct12_2

 

Bibblewindi Wells

Some of these well sites contained disused sumps (pits used during the drilling process), which had not been removed.

The sumps were drained and the soil remediated. Large areas of the operational sites were then rehabilitated to reduce the overall footprint.

Bibblewindi 13

Rehabilitation commenced October 2012 and completed November 2012.

 

September 2012

March 2013

July 2012

March 2013

 

Bibblewindi 16

Rehabilitation commenced October 2012 and completed November 2012.

 

May 2012

March 2013

May 2012

March 2013

 

Bibblewindi 17

Rehabilitation commenced October 2012 and completed November 2012.

 

July 2012

March 2013

May 2012

March 2013

 

Bibblewindi 21

Rehabilitation commenced October 2012 and completed November 2012.

 

May 2012

March 2013

September 2012

March 2013

 

Bibblewindi 27

Rehabilitation commenced October 2012 and completed November 2012.

 

May 2012

March 2013

July 2012

March 2013

 

Bohena

Bohena 5

Bohena 5 is one of approximately 30 wells Santos will not need in future operations and has decommissioned as part of its rehabilitation work.

Decommissioning of the well is known as a “plug and abandon”. Industry grade cement is pumped down into the well to “plug“ it, and the cement is then pressure tested to ensure it is effectively sealed.

The well head is removed and cut off at a depth greater than 1.5m below ground level and back filled with soil. The back filled area is then reclaimed with native vegetation and the site rehabilitated.

The whole site is then treated with gypsum and organic material to encourage natural revegetation.

Decommissioning Process

September 2012

Bohena5Sept12_1

Bohena 5 well head Plug and Abandon initiation

Bohena5WellHead

Plug and Abandon program in progress

Bohena5Plug

March 2013

Bohena5Oct12_1

Bohena 2

Rehabilitation began in May 2012 and was completed March 2013

October 2009

March 2013

January 2012

March 2013

Bohena 4

Rehabilitation began early 2012 and was completed March 2013

March 2012

March 2013

March 2012

March 2013

Bohena 8

The existing dam on site is used specifically for fire fighting purposes and a dedicated turning lane was built to enable easy access for water trucks to pump water. Rehabilitation began December 2012 and was completed March 2013.

July 2012

March 2013

July 2012

March 2013

Bohena 10

Rehabilitation began September 2012 and was completed March 2013

September 2012

March 2013

September 2012

March 2013

Bohena Ponds

As part of its operational review, Santos identified a number of ponds in the Pilliga that had been constructed at pilot well sites some years earlier, but would no longer be needed.

Following the development of rehabilitation plans and regulatory approvals these ponds were decommissioned and the sites rehabilitated in 2012.

First, water was removed and transported to the storage pond at Bibblewindi 3. The pond sediment was treated and the pond liner removed and both were transported to a licensed landfill for proper disposal.

Gypsum was then tilled into the soil to improve the condition. Groundwork was carried out to return the original contours of the area and organic mulch spread over the site to promote growth and assist rehabilitation.

As seen from the images, natural revegetation is in progress.

Bohena 3

Rehabilitation began October 2012 and was completed 14 November 2012

 

April 2012

March 2013

March 2012

March 2013

 

Bohena South

 

September 2012

March 2013

January 2012

March 2013

 
 Bohena 6

Rehabilitation began in April 2012 and was completed January 2013

 

April 2012

March 2013

 

Dewhurst

Some of these well sites contained disused sumps (pits used during the drilling process), which had not been removed.

The sumps were drained and the soil remediated. Large areas of the operational sites were then rehabilitated to reduce the overall footprint.

First, water was removed and transported to the storage pond at Bibblewindi 3. The pond sediment was treated and the pond liner removed and both were transported to a licensed landfill for proper disposal.

Gypsum was then tilled into the soil to improve the condition. Groundwork was carried out to return the original contours of the area and organic mulch spread over the site to promote growth and assist rehabilitation.

Dewhurst 6

Rehabilitation commenced February 2013 and completed February 2013

 

December 2012

March 2013

 

Dewhurst 8 Pond

Rehabilitation commenced October 2012 and completed January 2013

 

October 2012

March 2013

July 2012

March 2013

 

Dewhurst 9

Rehabilitation commenced February 2013 and completed February 2013

 

December 2012

March 2013

 

Dewhurst 10

Rehabilitation commenced February 2013 and completed February 2013

 

December 2012

March 2013

December 2012

March 2013

 

Dewhurst 13

Rehabilitation commenced December 2012 and completed December 2012

 

July 2012

March 2013

 

Dewhurst 15

Rehabilitation commenced December 2012 and completed January 2013

 

July 2012

March 2013

 

Dewhurst 16

Rehabilitation commenced December 2012 and completed December 2012

 

November 2012

March 2013

 

Dewhurst 17

Rehabilitation commenced November 2012 and completed December 2012

 

July 2012

March 2013

 

Dewhurst 18

Rehabilitation commenced December 2012 and completed December 2012

 

July 2012

January 2013

 

Wilga Park

The Wilga Park site was part of the initial clean up and upgrade in early 2012. Work was undertaken while more detailed remediation and rehabilitation plans were being developed and work programs finalised for other sites which involved more complex civil works.

Rehabilitation activities included removal of residual equipment and drilling supplies and work was completed in March 2012.

 

February 2012

October 2012

January 2012

October 2012