In recent years, traditional oil and gas operators have found novel means of extending the life of their assets and deferring onerous decommissioning costs by converting their facilities from gas production into CO2 injection. Whilst the task of designing for CO2 may sound simple, CO2 injection works in counter-intuitive ways, with previously established heuristics derived from years of experience in gas-condensate systems being quickly challenged as potentially dangerous. The world of CO2 injection is back-to-front compared with hydrocarbons; it isn’t simply a case of a change in flow direction.
Some of the design challenges explored in this paper are:
• Large density variability in CO2 systems and catering for the sensitive nature of changes to ambient temperatures that can impact the pressure of a shut-in system.
• Optimal pressure ratings of the vent and drains systems and how previous safety margins may be unsafe.
• Pipeline hydraulic modelling focused on new areas outside of the traditional suite of analysis, such as dense phase flow assurance and strange behaviours in depressuring operations.
• Understanding liquid water dropout being more of a concern than ice and hydrate formation.
• Injection wells counterintuitively flowing from low pressure to high pressure.
• Where to safely vent CO2 in an offshore facility: above or below the platform? In a loss of containment event, CO2 is non-flammable and therefore protection against jet impingement is no longer required. Or is it?
• Optimal storage vessel conditions and vessel safeguarding for liquefied CO2.

The optimised utilisation of identified storage resources and accelerated commercial CO₂ storage development is vital for CCS to play its important role in reducing emissions.
CO2CRC addresses this challenge through the Otway Stage 4 field program. This collaboration, involving multiple international partners, will demonstrate a suite of cost-effective reservoir management techniques that improve CO₂ storage potential, particularly in lower-quality reservoirs, maturing them for commercial readiness. By demonstrating enhanced injectivity, improved sweep, higher resolution modelling, and effective performance monitoring, Otway 4 will substantially improve CO₂ storage resource usage, furthering CO₂ storage as an economically viable solution.
Otway 4 includes:
• Acquisition and analysis of CO₂ saturation and chemical data during plume migration and trapping, combined with an investigation on fine-scale geological heterogeneity’s role in CO₂ flow dynamics, to refine modelling workflows, ultimately developing strategies for optimising commercial CO₂ storage.
• Demonstrating that CO₂ microbubbles, owing to their smaller size, lower buoyancy effect and enhanced dissolution properties, significantly increase storage efficiency compared to standard CO₂ injection, thereby unlocking previously untenable CO₂ storage reservoirs.
• Enhancing seismic monitoring to comprehensively assess storage performance and microbubble behaviour, including quantitative derivation of CO₂ saturation.
• Demonstrating the capability of Distributed Strain Sensing (DSS) to measure geomechanical changes associated with CO₂ injection quantitatively.
In addition to Otway 4’s forward plans, this paper discusses laboratory and modelling work, including core flood analysis to understand CO2 microbubble behaviour at pore scale, dynamic modelling of CO₂ flow through heterogeneous reservoir and selecting suitable injection intervals at the Otway site.

The Australian government has recently legislated a 43% emissions reduction target for 2030 to drive net zero ambitions for 2050. The government plans for Carbon Dioxide Capture and Storage (CCS) to play a significant role in achieving this through Greenhouse Gas storage license rounds. Rapid screening of Australia’s carbon storage opportunities is necessary to position future acreage release and ultimately identify and mature carbon storage sites.
An industry collaboration between Geoscience Australia & SLB has conducted a basin scale carbon storage assessment project for the Barrow and Dampier sub basins. The project has built and modernized a subsurface database fit for CCS screening. The dataset was used as the foundation to create a carbon storage opportunity portfolio and storage resource assessment for the basin.
The project has three major streams:
1. CCS focused reprocessing, depth imaging and merging of 29 legacy seismic surveys covering 26,150 sqkm – focus on detailed image resolution for containment analysis
2. A basin wide audit of 1600+ wells and databasing of available log data. 140 wells were carried through for petrophysical and rock physics analysis relevant to CCS.
3. A portfolio of carbon dioxide storage opportunities and associated capacity assessment for the Barrow Dampier sub-basins including saline aquifers and depleted fields ranked on storage capacity, reservoir and seal properties and integrity.
The results of this study will be released via NOPIMS as a public resource to expediate CCS implementation for the region.

Common user infrastructure (CUI) is crucial to accelerating industrial decarbonisation at the rate required to secure first mover advantages in the global market.​
Transitioning to a low-carbon economy presents tremendous economic opportunities. However, it also requires significant front-end risk and capital to bridge critical supply chain gaps, such as transporting carbon between capture and storage locations, or connecting manufacturing facilities to ports to enable lucrative export market access for our low-carbon goods. Any delay in bridging these gaps impedes upstream development investment decisions, which in turn slows the pace of transition. ​
CUI has been engaged before to overcome similar challenges, such as the tolling infrastructure model deployed for LNG; the recent government commitment to developing common Pilbara user electricity infrastructure to catalyse transition to renewable energy; as well as the government contributing finance to a common user rare earths processing facility in Eneabba.​
CUI reduces complexity, harnesses efficiencies of collaboration, captures economies of scale, and maximises asset capacity utilisation. In doing so, it becomes key to unlocking a network of upstream green industrial development underpinning the energy transition. ​
Our extended abstract paper and oral presentation (with accompanying slide show) will discuss key opportunities and challenges, drawing on examples including from WA, resonating with the conference emissions reduction themes of integrated energy and innovation & commercializing at scale. This will be of interest to energy industry leaders, including investors, developers and legislators. The scope of discussion will include ​​
- The critical role of common user infrastructure in decarbonisation​​
- Different development and operating models​
- Current and potential challenges​​
- Relevant case study insights​​

Common user infrastructure (CUI) is crucial to accelerating industrial decarbonisation at the rate required to secure first mover advantages in the global market.​
Transitioning to a low-carbon economy presents tremendous economic opportunities. However, it also requires significant front-end risk and capital to bridge critical supply chain gaps, such as transporting carbon between capture and storage locations, or connecting manufacturing facilities to ports to enable lucrative export market access for our low-carbon goods. Any delay in bridging these gaps impedes upstream development investment decisions, which in turn slows the pace of transition. ​
CUI has been engaged before to overcome similar challenges, such as the tolling infrastructure model deployed for LNG; the recent government commitment to developing common Pilbara user electricity infrastructure to catalyse transition to renewable energy; as well as the government contributing finance to a common user rare earths processing facility in Eneabba.​
CUI reduces complexity, harnesses efficiencies of collaboration, captures economies of scale, and maximises asset capacity utilisation. In doing so, it becomes key to unlocking a network of upstream green industrial development underpinning the energy transition. ​
Our extended abstract paper and oral presentation (with accompanying slide show) will discuss key opportunities and challenges, drawing on examples including from WA, resonating with the conference emissions reduction themes of integrated energy and innovation & commercializing at scale. This will be of interest to energy industry leaders, including investors, developers and legislators. The scope of discussion will include ​​
- The critical role of common user infrastructure in decarbonisation​​
- Different development and operating models​
- Current and potential challenges​​
- Relevant case study insights​​

In the frames of our research project devoted to carbon-neutral LNG, we concluded that the market has been facing credibility-related challenges due to lack of standards and transparency.
This year’s work focuses on the possibility, advantages and consequences of implementing carbon capture, utilization and storage (CCUS) technologies along the LNG value chain. We address the following questions :
- What level of emissions along the LNG value chain could be managed using only CCUS technologies?
- What elements of the LNG value chain is it feasible to manage using CCUS
- What is the price difference between decarbonizing the LNG value chain through CCUS in different regions?
- What is the optimal ratio between managing emissions with CCUS and compensating with carbon offsets?
Based on the data by NETL, we conduct a preliminary analysis of CCS CAPEX. We apply the cost estimation method (class 5) based on the US DOE Classification, to estimate the costs of using CCUS for emissions management in different countries (Qatar, USA, Australia and Russia) which were selected according to the database of carbon-neutral LNG cargoes delivered in 2019-2023, which the authors collected.
The study demonstrates:
- Due to the economic, geographical and infrastructural limitations, it is more feasible to implement CCUS on the producer's side.
- Such projects remain capital-intensive, which limits their applicability. As a result, we discuss what levels of combining CCUS with carbon offsets are feasible for the industry.
- What level of CCUS implementation is economically feasible for market participants