Quantitative Assessment of End-Of-Life Wells and Fields for Carbon Capture and Storage (CCS) Suitability

Abstract

Abstract In the coming decades many thousands of fields and tens of thousands of wells globally will reach the end of their commercial life due to dwindling production rates and will need to be decommissioned at a substantial cost. The scale of the task can be appreciated by considering that in Southeast Asia alone, it is forecast that approximately 1,500 platforms and over 7,000 wells are projected to need decommissioning by 2030 with costs estimated to range from $30 billion to as high as $100 billion (Evans, 2019). At the same time as the backlog for decommissioning grows, CO2 concentrations in the atmosphere continue to increase (www.co2.earth/daily-co2) without viable at-scale alternatives to eliminate fossil fuel use for the foreseeable future. Since governments world-wide (Carver, 2021) have committed to net zero targets or substantial reductions in CO2 emissions in the coming decades, there is a pressing need to address how to maintain use of fossils fuels (in countries and for activities for which there are no alternatives) while at the same time reducing or maintaining atmospheric CO2 concentrations at existing levels (12 countries have passed legislation on net zero targets and over 190 countries signed the Paris Agreement, a legally binding international treaty on climate change reached at COP21 in 2015, including all ASEAN nations). While the process of reducing or removing CO2 emissions from various sources is not straightforward for any country, there are a convergence of challenges faced by ASEAN nations. In the last two decades, a time of rapid economic development, renewable energy sources have not gained ground on fossil fuels in the overall total energy consumption of ASEAN nations (The World Bank, 2024) and data show a decrease in ratio of renewable energy generated compared to total energy consumed. Although the share of electricity generated from renewable sources increased from 2015 to 2020 it was insufficient to offset the increased fossil fuel use in transport and industry sectors (Lau, 2022). The slow increase in renewable energy generation can be partly attributed to sustainability concerns with both hydropower and bioenergy in ASEAN, for example, the over-damming of the Mekong River and the clearing of rainforest in Borneo (Lau, 2022). Furthermore, the deployment of other effective methods of renewable energy generation such as wind turbines and solar panels are less well suited to ASEAN countries. Minimum windspeeds across much of the region fall below the 4 m/s threshold level for efficient use of a wind turbine, except for coastal areas around Philippines and Vietnam where wind speeds are higher (Lau, 2022). Solar is rated as a moderate potential renewable source, with other parts of Asia rated higher, (Lau, 2022) but it requires a significant landmass to make a meaningful contribution, which is not available due to the dense population in ASEAN. Lau, 2022, assessed that it is unlikely that renewable energies will replace energy generated from fossil fuels within the 2030–2050 timeframe and fossil fuels will remain an important part of the energy mix requiring ASEAN countries to adopt strategies and technologies to mitigate CO2 emissions.