Compilation of CO2 release field experiments conducted worldwide for which the research results are publicly available prior to May 2017. This includes 14 field sites and 41 field experiments. For each field site, where possible, there is data on: The project: including primary aims, partners, total funding, duration, current status, website. Site information: including geology (target formation and overburden), hydrology, environment. Field experiment set-up: including injection depth, well orientation. Summary activity: total number of experiments at the site, total CO2 released. For each experiment at each site, where possible, there is data on: Injection parameters, including injection strategy, rate, duration, start and end date, CO2 source and properties, use of tracers; Site parameters, such as groundwater depth at time of experiment; Leakage to surface, including whether CO2 leakage to surface occurred, quantitation; Characteristics of surface leakage, including location, distribution, time taken to reach surface, evolution as experiment progresses; Subsurface CO2 spread, in soil gas and groundwater interaction, environmental impact; Monitoring including area monitored, duration of monitoring before, during, and after the release. Data sources are clearly cited. Paper reference: https://www.sciencedirect.com/science/article/pii/S0012825218304264?dgcid=author.