Cliff Head Oil Field
The Cliff Head Oil Field (Cliff Head) and Cliff Head Alpha (CHA) platform is located about 270 kilometres north of Perth, Western Australia. Our project is in a shallow marine environment, in water depths of 15 to 20m, about 12 kilometres offshore from Dongara.
The project is in Production License WA-31-L which covers 72km², and the oil field covers 6km² in the Commonwealth Exploration Permit WA-286-P.
The platform is visible from shore and, at present, produces approximately 700 to 800 bopd to (110 to 125m3/d) from the Cliff Head field. The oil is heavy and waxy and the reservoir has very low pressure resulting in a very low environmental spill and impact risk. Reservoir fluid, both oil and water, is produced from five production wells using electrical submersible pump (ESP) wells.
Two 14km long pipelines leave the platform and traverse the seabed and underneath the coastal dune systems and then connect with our onshore Arrowsmith Stabilisation Plant. Crude oil and water are separated at the plant, in the Arrowsmith Industrial Complex. The separated produced water, often called produced water, is pumped back to the offshore platform where it is reinjected into the reservoir to provide reservoir pressure support, by three injection wells.
These Cliff Head platform and processing facilities are the only offshore and operating onshore infrastructure in the Perth Basin area. They are important infrastructure for any nearby development.
The processed crude is stored onsite at ASP in three 10,000 barrel tanks. Once full, we bring a chartered tanker into the Port of Geraldton then transfer approximately 27,000 barrels of oil to the tanker by road train. The tanker then anchors off Geraldton whilst the storage tanks at ASP are refilled, it comes back into Geraldton, is filled further, then departs for Asia to unload and sell the oil.
An increase in reserves is possible from a combination of wildcat exploration wells as well as infill reserves from already producing reservoirs as well as near-field target opportunities. An Asset Life Extension Program is underway to ensure the integrity of Cliff Head’s essential infrastructure into the future.
Cliff Head field was the first commercial oil discovery that was developed in the offshore Perth Basin, Western Australia. The development cost was A$327m and first oil production commenced in May 2006. So far, the field has produced over 14.8 million barrels of crude oil and it continues to produce oil at daily volumes that are higher than originally forecast.
In June 2016, Triangle acquired a non-operating 57.5% interest in Cliff Head, including the Arrowsmith onshore oil processing plant, from an Australian oil and gas company, AWE Limited (ASX:AWE). The 42.5% operating interest was owned by Roc Oil Company Ltd (Roc). In 2017, Triangle and Royal Energy entered into a 50/50 agreement and purchased the remaining 42.5% interest in Cliff Head from Roc Oil Company Ltd.
Triangle Energy (Operations) Pty Ltd became the Registered Operator of the Cliff Head asset on the 17th July 2018. Triangle now holds a 78.75% interest in Cliff Head and is the Operator and Royal Energy holds a 21.25% interest.
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Triangle has a strong focus on reserves replacement by exploration as well as detailed full field subsurface modelling and re-interpretation.
The 2018 results indicated there is potential to recover additional resources and reserves from the Company’s discovered and already producing reservoirs that we call the Main Horst, West, South and South East Fault Blocks. As well, the static modelling revealed additional near field targets (see announcement 10 July 2018) with up to 29 million barrels (unrisked, best estimate, evaluation date 2 July 2018) of prospective oil initially-in-place (OIIP) that represents 10.2 million barrels of prospective resource in near field exploration targets within the Cliff Head license area.
These near field prospects are located in close proximity to Cliff Head’s discovered, producing reservoirs. The development of these volumes would therefore likely take advantage of existing pipelines and infrastructure with specific tie in pipelines being the main development commitment. Prospective OIIP volumes are in addition to OIIP in the discovered, already producing Cliff Head reservoirs.
Triangle’s approach gives a high degree of confidence in the prospect evaluation. A prospective volume of 29 million barrels against the previous estimate of 15.8 million barrels is over an 80% increase in prospective OIIP. The results from the static model completes the picture on what the future of Cliff Head could look like. With this result, the Triangle team will now generate a full near field exploration program to test and confirm the volumes. The near field exploration program will be executed in conjunction with Cliff Head development activity, where an integrated Cliff Head development-exploration offshore program is expected to be put in place for 2019. Successful opportunities would leverage current infrastructure which would expedite crude to market.