First downhole sampling of a natural hydrogen reservoir in Colombia

In Colombia, natural hydrogen (H 2 ) was recently declared a source of unconventional renewable energy. An opportunity has been recognized to take advantage of information on the infrastructure of oil fields as a springboard for H 2 exploration in the country’s sedimentary basins. Establishing similarities and identifying components of the possible H 2 systems in the different geological contexts where the presence of H 2 has been proven in Colombia’s sedimentary basins allows the establishment of the probability of H 2 in the Ecopetrol oil and gas fields in Colombia. The components of H 2 systems include potential H 2 source rocks and reservoirs. Potential accumulations need to be confirmed through measurements, sampling, and well testing. The main types of H 2 well exploration carried out in this study resemble those in oil fields and include surface surveys, logging while drilling (mud gas and petrophysics), and downhole sampling. In the case of a hydrocarbon field in the Llanos Basin, a detailed seismic and geological review, supported by surface survey indications of H 2 traces, prompted further investigation while drilling wells in the basin to establish the provenance and distribution of H 2 . Based on the proposed workflows, we evaluated possible strategies in the area. Given the positive evaluation of the possible elements of a theoretical H 2 strategy, a sampling plan was defined both in the well and on the surface that will reduce the uncertainty of the prospect of natural H 2 in the studied basin but may also be applied to similar geological settings worldwide. This study shows the application of such an H 2 exploration strategy, leading to the presented results from the first well and confirming the presence of an active natural H 2 system in the Llanos Basin.