Activity description and location map have been extracted from the EP submission (refer to Guideline – Making a Submission to NOPSEMA N-04000-GL0225).
Location
The Cliff Head oil field is located off the Western Australian coast (Production Licence WA-31-L), west of the Big Horseshoe Reef; approximately 20 km south-southwest of Dongara (An unmanned well head platform, Cliff Head Alpha (CHA) to accommodate the well heads and support equipment;
Eight well heads with the current arrangement of five production wells with electrical submersible pumps (ESPs) to enable artificial lifting of the produced fluid (i.e. crude oil and water), and three water injection wells;
An insulated subsea production pipeline, which transports the produced fluids from CHA to the onshore Arrowsmith Stabilisation Plant (ASP);
An insulated subsea water injection pipeline from ASP to the three injection wells at CHA; and
A subsea power and communication cable, and chemical supply umbilical running from ASP to CHA.
The production pipeline transports the produced fluids from the CHA to the ASP where oil is separated from the produced formation water (PFW). The PFW is then transported via the water injection pipeline to the injection wells, where it is then injected into the geological formation that hosts the hydrocarbon reservoir.
The offshore components of the pipelines that lie within Commonwealth waters are approximately 4.9 km in length and are operated under pipeline licence WA-12-PL, which is administered by National Offshore Petroleum Titles Administrator (NOPTA). The offshore components of the pipelines that lie within state waters (i.e. between the state waters limit and the mean low water mark) are approximately 6.9 km in length and are operated under pipeline licence TPL/18, which is administered by the Western Australian Department of Mines and Petroleum (DMP).
The water depth in the vicinity of the field is approximately 18 m and the closest landfall is some 11 km due east. The field itself is approximately 1,260 m below sea level. The wells are tied to the Cliff Head Alpha (CHA) (Figure 2-2) wellhead platform located at 29° 27’ 00.4” S 114° 52’ 12.1” E. The production and water injection pipelines traverse the seabed within Commonwealth waters, avoiding sensitive areas such as Horseshoe reef. The pipelines cross into State waters at approximately -29° 23’ 59.9994” S 114° 54’ 0” E.
A Petroleum Safety Zone (PSZ) of 500m has been gazetted around the CHA Platform facility.
 
Overview of the Cliff Head Oil Field Development
Production from the Cliff Head Oil Field Development involves transferring oil and produced formation water (PFW) from the offshore wellhead to the ASP via the offshore and onshore pipeline. At the ASP the PFW is removed from the product stream, the crude oil is stabilised and then transferred to road tankers and transported for refining.
This Environment Plan considers only the offshore components of the Cliff Head development, namely those that occur beyond the Commonwealth-State boundaries at 3nm from the coastline, these are:
An unmanned well head platform, Cliff Head Alpha (CHA) to accommodate the well heads and support equipment;
Eight well heads with the current arrangement of five production wells with electrical submersible pumps (ESPs) to enable artificial lifting of the produced fluid (i.e. crude oil and water), and three water injection wells;
An insulated subsea production pipeline, which transports the produced fluids from CHA to the onshore Arrowsmith Stabilisation Plant (ASP);
An insulated subsea water injection pipeline from ASP to the three injection wells at CHA; and
A subsea power and communication cable and chemical supply umbilical running from ASP to CHA.
The production pipeline transports the produced fluids from the CHA to the ASP where oil is separated from the produced formation water (PFW). The PFW is then transported via the water injection pipeline to the injection wells, where it is then injected into the geological formation that hosts the hydrocarbon reservoir.
The offshore components of the pipelines that lie within Commonwealth waters are approximately 4.9 km in length and are operated under pipeline licence WA-12-PL, which is administered by National Offshore Petroleum Titles Administrator (NOPTA). The offshore components of the pipelines that lie within state waters (i.e. between the state waters limit and the mean low water mark) are approximately 6.9 km in length and are operated under pipeline licence TPL/18, which is administered by the Western Australian Department of Mines and Petroleum (DMP).