Triangle Energy finds new drilling prospects near Cliff Head platform

Australia-based Triangle Energy has identified three key opportunities that could be drilled and developed from the existing Cliff Head Alpha platform offshore Western Australia.

Cliff Head platform; Source: Triangle Energy
Cliff Head platform; Source: Triangle Energy

Triangle said on Thursday that the drilling opportunities were identified during the now completed Cliff Head Renewal Project (CHRP).

According to the company, the total number of opportunities is actually five, with two of them being longer-term development prospects.

Of the three priority drilling targets, the Mentelle Updip prospect has the potential to materially impact the life-cycle of Cliff Head, while West High and SE Nose could also provide a significant uplift in production.

Triangle managing director Rob Towner said: “It is pleasing that our work completed over the last 12 months or more has led us to a point where we have three clearly defined, attractive, drilling opportunities. The next steps for us are to commence the detailed well planning to execute these wells, within the constraints of the current oil price and industry down-turn.

The work we have done for the Cliff Head Renewal Project gives us a clear picture of how the under-explored Perth Basin could be developed around existing infrastructure, extending the life of the Cliff Head project”.

As part of the Cliff Head Renewal Project, executed during the second half of 2019 and the first quarter of 2020, Triangle undertook a range of sub-surface studies to mature several previously identified opportunities which are now contingent on an investment decision.

These included a review of the mapping and reservoir interpretation, reprocessing of the Cliff Head 3D seismic data, depth conversion studies, and dynamic modelling of the field and satellite opportunities.

High-potential Mentelle Updip prospect

The Mentelle Updip prospect was reviewed with a focus on the reservoir interpretation which had been a key uncertainty.

Work on the prospect indicates that good quality Irwin River Coal Measures sandstone reservoirs could be expected within the prospect and confirmed the large structure as previously mapped.

Best estimate prospective resources have been upgraded to 5.2 mmstb, from 3.3 mmstb previously. The chance of discovery for Mentelle Updip is assessed to be 38 per cent and a 34 per cent chance of a commercial discovery.

West High appraisal & development

The West High appraisal and development opportunity is a probable extension of the Cliff Head field to a western culmination.

It could be drilled by a deviated appraisal well from Cliff Head platform and Mentelle Updip then completed as a production well in the event of success. Triangle completed a detailed depth conversion review using the reprocessed Cliff Head 3D seismic data to reduce this key uncertainty with the opportunity.

A best estimate contingent resource of 0.95 mmstb is assessed for West High. The progression of West High contingent resources to reserves is contingent on the drilling results of a West High appraisal well.

SE Nose development

SE Nose is a low relief structure updip of the Cliff Head 1 discovery well. The depth conversion studies also addressed the structural uncertainty of SE Nose and confirmed the presence of a structure updip of Cliff Head 1.

SE Nose is assessed to have best estimate contingent resources of 1.01 mmstb with the conversion to reserves dependent on a formal Cliff Head JV approval of a development well.

The company also identified the longer-term Catts and Far North prospects. Catts, immediately north of SE Nose was identified by the depth conversion work with best estimate prospective resources assessed to be 0.77 mmstb with a 45 per cent chance of discovery – and a 35 per cent chance of a commercial discovery.

Far North is a possible structural culmination on the northern limit of the field that is indicated by upside scenarios of the depth conversion work. It is in its early stages of evaluation with a best estimate (2C) contingent resource estimated to be 0.4 mmstb.

A possible southern extension with best estimate contingent resources of 0.54 mmstb was also identified but is contingent on further studies.

It is also worth noting that Triangle updated its assessment of unrisked contingent resources and prospective resources for the Cliff Head Project. Currently, the best estimate contingent resources stand at 3.52 mmstb gross, while best estimate prospective resources for total 9.46 mmstb gross.