Japan aims for net zero emissions by 2050, and the application of carbon neutral technology is being considered to achieve this goal. CCUS/CCS is currently being considered as a promising method of implementing this carbon neutrality. In this presentation, we outlined the status of discussions regarding this implementation.

The world is currently in a situation where the concentration of carbon dioxide in the air has been rising since the Industrial Revolution as a result of the massive consumption of fossil fuels, as a result of population growth and economic growth, and the increase must be halted.

In the energy sector as well, it must be considered that shifting from a linear economy to a circular economy in order to build a sustainable society while protecting the global environment.

While it is important to reduce the use of carbon, an essential element of fossil fuels that has supported the world’s energy, and to switch to carbon-free fuels such as hydrogen, it is also necessary to adopt a method of recycling carbon in order to fully utilize the current infrastructure, considering the continuity of energy supply. This part of the report outlines the carbon capture, utilization, and storage technologies and anthropogenic carbon cycling energy systems needed to transition to a carbon-circulating economy, while also introducing the status of efforts overseas.

During the 4.6 billion years of history, the earth has repeatedly warmed and cooled. It is very common for the Polar Regions to have no ice. On the other hand, the theoretical surface temperature of the earth is -18 °C, and due to the presence of greenhouse gases in the atmosphere and their delicate balance, the average temperature is 15 °C, making it a comfortable environment for living things. It is recognized that the current global warming is clearly caused by human influence, even from the rate of temperature rise. Carbon recycling has been proposed as a means to stop this warming. Since most of the current carbon dioxide emissions are generated by combustion of fuel, recycling to fuel would be the main course. This paper introduces recycling technology for methane, a typical fuel, and describes the ideal form of carbon recycling.

Towards the realization of a net zero carbon society by 2050, INPEX has committed to proactively engage in energy structure reformation, while responding to the growing energy demands of Japan and the world, and fulfilling its responsibility for the development and stable supply of energy over the long-term. In February 2022, INPEX has released INPEX Vision@2022 which describes the basic management policy, vision for around 2030, initiatives in the 5 net zero businesses as the long-term strategy towards the realization of a net zero carbon society by 2050. This paper summarizes the vision and major activities relating to the INPEX’s 5 net zero businesses that are hydrogen / ammonia, carbon capture and storage（CCS）/ carbon capture, utilization and storage（CCUS）, renewable energy, carbon recycling and forest conservation.

Immiscible hydrocarbon gas enhanced oil recovery（HCG-EOR）in full-field scale has been operated in Lower Miocene sandstone reservoir in Rang Dong Field offshore Vietnam since 2014. The EOR has been implemented in tertiary water-alternating-gas（WAG）scheme and certain incremental oil was observed; however, reduction of sweep efficiency and operation problems due to severe gas breakthrough were encountered in several wells due to difficulty of conformance control in heterogeneous layers. To address the issues, optimal field operation and new reservoir characterization methods were applied. In term of field operation, WAG ratio was increased and gas oil ratio was successfully reduced while maintaining oil production rate. To reproduce the actual gas breakthrough behavior and find more optimal WAG ratio by dynamic simulation approach, firstly inter-well connectivity in a certain area was investigated using capacitance resistance models（CRMs）. Being supported by the available tracer monitoring data, the result suggested strong one-to-one well connectivity and improved the predictability of reservoir simulation based on updated geological concepts. Then, with the updated model, opportunity of conformance control and WAG efficiency improvement was studied including the extension to a simulation scoping work of foam-assisted WAG application. In this paper, the efforts to tackle the issue of HCG-EOR in the mature oil field are comprehensively introduced.

Oil and natural gas yet provide main supply of the energy that is essential for sustaining economic and social activities. On the other hand, CO₂ emissions from fossil fuels are viewed as a problem in light of the circumstances where the reduction of greenhouse gases in the atmosphere is urgently required as a countermeasure against climate change. Petroleum exploration and production companies are required to achieve simultaneously both a stable supply of oil and natural gas and reduction of greenhouse gas emissions, and to reduce their net CO₂ emissions to zero. This paper describes the importance of geomechanics, the technical discipline for handling the deformation and failure of geological formations, associated with both oil development and carbon neutral technologies. Geomechanics has made significant technological progress during the unconventional resource development since the beginning of the 2000s, contributing to the stable supply of energy. In the 2020s, as the world moves toward the realization of a carbon-neutral society, the application of geomechanics will expand from the field of oil development to fields such as geothermal energy development and CCS, building a bridge to the carbon-neutral society. A workflow using geomechanical models for systematic and quantitative investigation on geomechanical issues is also presented, and the development of key techniques necessary for carrying out the workflow including practical geomechanical model construction, coupled fluid flow and geomechanical modeling, and long-term continuous monitoring is introduced in this paper.

Gases were sampled from 7 surface gas seeps including 2 mud volcanoes in the Niigata oil and gas basin. Based on the gas compositions and isotope compositions, the origin, maturity, migration, and alteration of gases were studied. A seep gas from the paddy field is interpreted to be microbial. The other 6 gases are thermogenic, or the thermogenic gases were generated in the peak to late oil generation stage. Some gases show high C₁/(C₂+C₃), mixtures of thermogenic and microbial. The methane, ethane, and propane carbon isotope compositions suggest that suggesting molecular fractionation during the migration to the surface. The ¹³C-enriched propane and heavy δ¹³C values (>+2 ‰) of CO₂ in some gases, especially in gases from the mud volcanoes, indicate active processes of the secondary microbial methanogenesis accompanied by biodegradation of petroleum. The microbial processes could proceed during the residence time in the mud chambers, which are estimated to exist several hundred meters below the mud volcanoes.