3D Energi Limited (the “Company”; ASX: TDO) is pleased to announce results from the Ora formation testing
at Essington-1 in VIC/P79 exploration permit, offshore Otway Basin, in which TDO has a 20% participating interest.
Highlights
- A gas discovery has been confirmed within the primary Waarre A and secondary Waarre C reservoirs with reservoir properties in line with pre-drill predictions.
- Ora formation testing has been successfully completed across three (3) zonesin the primary Waarre A target at Essington-1.
- Ora formation testing was focused on the Waarre A reservoir, where limited reservoir and production data exists across the Otway Basin compared with the Waarre C.
- Ora, a new cost-effective and environmentally responsible technology, provides accurate insights into reservoir productivity while reducing operational impact and environmental footprint. This marks its first deployment in Australia.
- Ora results support effective reservoir quality and deliverability in two (2) of three (3) tests and provide key input data for ongoing assessment of commerciality.
- A low reservoir quality zone was chosen for the third test to confirm the limit of moveable gas. Fluid sampling appeared to be successful with sample capture and composition to be
confirmed onshore.
- Downhole fluid analysis supports the presence of gas condensate with low concentrations of CO2 (3-4%) in all tests, consistent with MDT samples.
- Recovered gas samples will undergo laboratory compositional and PVT analysis to support forward resource evaluation.
Ora Formation Testing – Overview
Deep Transient Testing (DTT) has been successfully completed on the Essington-1 Waarre A reservoir using Schlumberger’s Ora formation testing platform.
Ora formation testing was focused on the Waarre A reservoir at Essington-1, where limited reservoir and production data exists across the Otway Basin. Deliverability of the Waarre C reservoir is better understood from regional reservoir and production data, and did not require further testing at Essington-1. Testing the Waarre A provides valuable new data from a step-out area to support field evaluation.
Ora has been successfully deployed across major oil and gas regions globally, including the Middle East, North
Sea and Gulf of Mexico. This marks the first use of the Ora platform in Australia, reflecting a commitment to apply innovative methods that enhance data quality, reduce testing time and operational costs, and minimise environmental impact by eliminating the need for extended well flow and flaring.
Ora Formation Testing – How Does it Work?
During the Essington-1 program, Ora carried out controlled pressure drawdowns and build-ups across three
(3) zones in the Waarre A reservoir to:
- Confirm average zone permeability, mobility and connectivity
- Assess in-situ fluid properties
- Recover representative hydrocarbon samples for PVT and compositional laboratory analysis
The Ora testing platform performs a Deep Transient Test (DTT) which involves pumping gas from the reservoir
and monitoring pressure build-up with high accuracy downhole gauges to determine the average permeability (how easily the fluids can flow through the rock) of the test interval within a radius of investigation.
Ora Demonstrates the Permeability and Deliverability of the Waarre A
Ora formation testing was performed across three (3) carefully selected zones within the Waarre A reservoir,
chosen to represent a range of reservoir qualities interpreted from wireline logs. The objective was to assess
reservoir performance across these variations and better understand each zone’s contribution to overall
recoverable volumes.
Ora results provide confidence in the reservoir’s capacity to transmit gas and support the interpretation of
a gas-condensate charged system.
Moderate to excellent reservoir in the Waarre A
Tests 2 and 3 were conducted in intervals of moderate to excellent reservoir quality, both confirming the presence of moveable, producible gas-condensate within better-developed sandstone units of the Waarre A reservoir.
Test 2 represents the upper end of reservoir performance, with very high mobility and excellent connectivity indicative of an excellent sandstone reservoir. Test 3, while lower in quality due to increased argillaceous content, still exhibits good mobility and moderate permeability, confirming that argillaceous sandstones retain effective flow capacity.
The combined results show that the productive portions of the reservoir comprise laterally connected and transmissive sandstone units with effective flow characteristics, albeit with performance varying according to sand quality and clay content.
Finding the Limit of Moveable Gas in the Waarre A
Test 1 was positioned in a low-quality argillaceous siltstone to evaluate the lower limit of moveable gas within the Waarre A reservoir. The test exhibited very low mobility and permeability, with only limited radial flow achieved despite a long test duration. This data will be important in refining our evaluation of net productive reservoir as we refine our geological model and update resource estimates.
Fluid Analysis Predicts Gas Condensate with Low CO2 Concentrations
Downhole fluid analysis across the Waarre A test zones, together with gas monitoring at surface during the
tests, has confirmed the presence of gas and predicted condensate presence with a preliminary Condensate Gas Ratio (CGR) of ~30-33 stb/MMscf in all tested zones (further laboratory analysis will provide confirmation).
CO2 concentrations from the Ora downhole compositional fluid analyser are consistent with those from preliminary rig-based MDT samples, having measured CO2 concentrations of 3-4%. Further analysis is required to confirm these initial results. Low CO2 concentrations present favourable characteristics from a development perspective for the following reasons:
- Higher concentrations of recoverable gas-condensate
- Processing of low CO2 gas is easier and more cost effective
- Lower CO2 lifecycle emissions
The Ora tool has recovered hydrocarbon samples from two (2) of the tested intervals for detailed onshore laboratory-based compositional analysis. During sample acquisition, Ora sampling pressures and compositional monitoring indicated successful acquisition of two (2) gas samples from Test 1 and one (1) gas sample from Test 2. No samples were planned or attempted to be recovered from Test 3.
Confirmation of successful sample acquisition will be confirmed once analysis commences at the laboratory. Laboratory results will provide definitive gas composition across the full C-range (C1–C6+), plus reservoir fluid properties required for development studies.
Forward Work Program
Ora results will now be integrated and analysed alongside all formation evaluation data collected during the Essington-1 drilling program to refine the geological model, update resource estimates and assess potential commercialisation pathways.
Any assessment of project commerciality requires integration of full subsurface datasets, development concepts, production forecasts, economic modelling, and market conditions. While Ora results provide confidence in the reservoir’s capacity to transmit gas and support the technical potential of the Waarre A reservoir, they should not be interpreted as a guarantee of future production performance or economic outcomes.
Essington-1 will be plugged and abandoned in accordance with the approved Environment Plan, after which
the Transocean Equinox will mobilise approximately 20km to the northwest to drill the Charlemont-1 exploration well.
Executive Chairman’s Comments
Mr Noel Newell, Executive Chairman of 3D Energi, said today “A gas-condensate discovery with strong support for reservoir deliverability is an incredible start to the Otway Exploration Program for the Joint Venture and 3D Energi shareholders. Ora testing has confirmed reservoir deliverability in key Waarre A
intervals and delivered the type of high-quality subsurface data needed to progress our technical and commercial evaluation. This is the first time the Ora technology has been deployed in Australia, and its successful application has allowed us to acquire crucial reservoir insights while reducing environmental
impact. We now shift our immediate focus to Charlemont-1 where we hope to replicate the outstanding results at Essington.”