Fractured basement reservoirs are found in metamorphic and igneous rock where faulting has led to the creation of a fracture network, underlying a sedimentary basin.
Not to be confused with companies engaged in ‘fracking’, Hurricane’s interest is in naturally fractured reservoirs in rock that was formed over two billion years ago. Over time, in certain places these massive basement structures have been pushed up and violently fractured by earthquakes and other tectonic forces.
Unlike sandstone reservoirs that hold oil in the rock and have provided much of the world’s oil over decades, fractured basement rock is very hard and brittle, composed of rocks such as granite. Billions of cracks have been created when the basement structures moved through tectonic action, resulting in seismic scale faults and highly connected fracture networks.
For Hurricane it is these faults and fractures that are most interesting because that is where, under the right conditions, significant volumes of oil accumulate. The oil is not in the rock, it is in the cracks between the rock. Hurricane has already found a material volume of oil in fractured basement reservoirs in the UK that is potentially a strategic resource for the country.
How does oil get into the basement?