Origin Energy – Enterprise 3DTZSS EPBC Act Referral Referral of proposed action Proposed Enterprise Three-dimensional Transition Zone Seismic Survey action title: (3DTZSS) 1 Summary of proposed action 1.1 Short description Origin Energy Resources Limited (Origin) operates the Otway Gas Project in the Otway Basin of southwestern Victoria. The Otway Gas project consists of the Otway Gas Plant, near Port Campbell, and offshore wells which supply gas to the plant through a series of pipelines. A fundamental component of operation of the Otway Gas Project is exploration for offshore gas reserves. Exploration underpins ongoing delivery of domestic gas supply via the Otway Gas Plant. As part of the exploration program for the Otway Gas Project, Origin is proposing to undertake an offshore transition zone seismic survey during. The survey, the Enterprise three-dimensional (3D) Transition Zone Seismic Survey (Enterprise 3DTZSS, herein referred to as the ‘survey’), is designed to map geological formations within the offshore exploration permit Vic/P42(V). To enable mapping of the offshore permit seismic activities must also be undertaken in adjacent on-shore areas. These on-shore areas are Petroleum Exploration Permit (PEP) 168, PEP169 and Petroleum Production Licence (PPL) 8. The fold coverage area for the survey (the ‘acquisition area’) will cover an offshore area of up to approximately 80 square kilometres (km2) in water depths ranging from approximately 2 metres (m) to 40 m. The onshore survey will take place alongside approximately 50 linear kilometres of existing roads and tracks. No private properties or waterways will be accessed for the onshore survey (Figure 1a and Figure 1b). 1.2 Latitude and longitude The geographic coordinates of the boundary of the Enterprise 3DTZSS survey area are presented in Table 1 below. Table 1. Geographic coordinates of the boundary of the Enterprise 3DTZSS area Point Latitude Longitude Location note 1 38° 34’ 30.6” S 142° 50’ 31.6” E Top left hand corner 2 38° 36’ 50.9” S 142° 49’ 19.2” E Bottom left hand corner 3 38° 37’ 37.5” S 142° 50’ 44.9” E 4 38° 39’ 23.3” S 142° 57’ 57.1” E 5 38° 39’ 55.0” S 142° 58’ 46.2” E 6 38° 41’ 06.5” S 143° 01’ 22.1” E Bottom right hand corner 7 38° 37’ 31.1” S 143° 03’ 37.8” E Top right hand corner 8 38° 36’ 43.0” S 143° 02’ 15.7” E Rounds Road 9 38° 36’ 22.8” S 143° 00’ 00.5” E Port Campbell Road 10 38° 36’ 23.5” S 142° 58’ 52.4” E Curdievale-Port Campbell Road 11 38° 36’ 15.7” S 142° 57’ 15.4” E Sharps Road 12 38° 35’ 47.0” S 142° 54’ 11.5” E Timboon-Peterborough Road 13 38° 34’ 41.9” S 142° 51’ 19.8” E Old Peterborough Road GDA94, MGA 54 Referral of proposed action (DoEE August 2016 template) Page 1 of 102 Origin Energy – Enterprise 3DTZSS EPBC Act Referral Figure 1a. Enterprise 3DTZSS location map Referral of proposed action (DoEE August 2016 template) Page 2 of 101 Origin Energy – Enterprise 3DTZSS EPBC Act Referral Figure 1b. Detail of roads included in the Enterprise 3DTZSS area 1.3 Locality and property description The area defined as the onshore ‘survey area’ covers approximately 50 linear kilometres and is located entirely within public roadside reserves and tracks in Peterborough and Port Campbell (in southwest Victoria (see Figure 1b). Offshore, the survey area covers 80 km2 in water depths ranging from approximately 2 m to 40 m and will take place entirely within Victorian state waters. The nearest landfall to the offshore survey area is approximately 200 m, with the nearest survey lines being 900 m from the town of Port Campbell and 850 m from the town of Peterborough. 1.4 Size of the development footprint or work The offshore survey area is 7,390 ha and the onshore area (hectares) survey area is 3,767 ha, for a combined total of 11,157 ha. 1.5 Street address of the site The location of the survey stretches from just west of Peterborough, Victoria, to just east of Port Campbell, Victoria. See Figure 1a for the location. 1.6 Lot description Not applicable. No private property will be accessed. Onshore, the survey will be restricted to road reserves. Referral of proposed action (DoEE August 2016 template) Page 3 of 101 Origin Energy – Enterprise 3DTZSS EPBC Act Referral 1.7 Local Government Area and Council contact (if known) The proposed survey area west of the Curdies Inlet is located within the Moyne Shire, while the area to the east of the Curdies Inlet is located within the Corangamite Shire. The proposal is not subject to local government planning approvals. 1.8 Time frame The survey is scheduled to take place over approximately four to five weeks (28-35 days) during the period 1st November to 31st March in permit year 2016/17 or 2017/18. Exact timing is contingent on receipt of environmental approvals, confirmation of contractor resources and fair sea state conditions suitable for marine seismic acquisition. 1.9 Alternatives to proposed action There are no alternative locations that will meet Origin’s regulatory obligations relating to the exploration permits. The objective of the Enterprise 3DTZSS is to image potential gas resources that, if developed, will assist in securing continued gas supplies for Origin’s Otway Gas Plant. As part of the survey Origin proposes to place seismic receivers within the Port Campbell National Park (PCNP), along the grassy verges of existing access tracks. No vegetation clearing is proposed, and no seismic source will be used within the PCNP. No access into the Bay of Islands Coastal Park (BICP - located to the west of Curdies Inlet) will be necessary for the survey. In the event that government approval to undertake surveying along the nominated access tracks within the PCNP is not provided under the National Parks Act 1975, Origin proposes to deploy nodes within existing cleared areas within the Port Campbell Rifle Range. Data obtained in this manner will be of lower quality than that obtained by gaining access to the PCNP due to the larger geographic range encompassed by placement of nodes adjacent to tracks within the PCNP. As such, access to tracks within the PCNP is strongly preferred. There are no reasonable exploration technology alternatives that will meet Origin’s technical and commercial objectives for the survey, or obligations to the State of Victoria, to acquire this data. The Enterprise 3DTZSS has been designed to bridge a data gap between the Enterprise 3D marine seismic survey (undertaken during 2014) and the coastline, providing fold coverage into the nearshore area of the Origin VIC/P42(V) permit. The structural regime in this area is very complex, making 2D data inadequate when trying to resolve the steep bedding dips and structural complexity. The timing of the proposed survey is linked to environmental constraints for the offshore component of the survey, most notably the seasonal presence of pygmy blue whales, southern right whales and poor sea state. 1.10 Alternative time frames, locations or No. As per Section 1.9. activities 1.11 Commonwealth, State or Territory Yes. See Section 2.5. assessment 1.12 Component of larger action No. If the proposed action confirms the presence of gas resources, it may be followed by an exploration drilling campaign, likely using the same onshore to offshore extended drilling technology used for the Halldale Speculant project (EPBC 2011/5879). This will be subject to a separate EPBC Referral, if required. 1.13 Related actions/proposals No. 1.14 Australian Government funding No. 1.15 Great Barrier Reef Marine Park No. Referral of proposed action (DoEE August 2016 template) Page 4 of 101 Origin Energy – Enterprise 3DTZSS EPBC Act Referral 2 Detailed description of proposed action 2.1 Description of proposed action Purpose The purpose of this survey is to map geological formations within the offshore exploration permit Vic/P42 (V). The data acquired will be used to map geological formations within the offshore exploration permit Vic/P42(V), and assess the potential of these formations to hold gas deposits. Seismic surveying is a low-impact, widely used exploration method used to define and analyse subsurface geological structures in both terrestrial and marine environments. There are two main components to any seismic survey, 1) a source and 2) a receiver. In simple terms the source inputs sound energy into the earth and the receiver records the sound signal reflected back from rock layers (Figure 2). Figure 2. Stylised illustration of the transition zone survey process Onshore Survey Source equipment To generate the energy required to image the subsurface, vehicles called vibroseis buggies are used. These vehicles will be used only along the Great Ocean Road (GOR). These buggies are fitted with a hydraulic piston and a base plate (Photo 1). The base plate is placed on the ground by the hydraulic piston, which then generates a range of frequencies into the ground through a vibration process. The vibration length and frequency range will be decided at the beginning of the survey following a range of vibe parameter sweep tests. Once at the source point (located every 12.5 m along the survey line), the operator lowers the base plate and the recording truck is informed that it is ready at its position. As long as it is safe to do so, the recording truck then sends a radio signal to start the vibration. Each vibration will last between 8 to 24 seconds depending on the in- field testing and the frequency range selected to best image the subsurface target reflectors.