Drilling using light equipment technology
Drilling boreholes using O&G industry standard rigs is expensive, which reduces the number of wells drilled during exploration and therefore reduce the amount of data available for reservoir characterization. Drilling using light equipment technology (adapted from the mining industry) presents a distinct advantage in offering the ability to obtain fully cored wells that cost less than wells drilled with hydrocarbon rigs. This is of high interest for CO2 storage and site characterization. The technology however has only been tested at depths of up to 1500m at Hontomin Technology Development Plant.
The original plan at Hontomin was to use conventional O&G drilling techniques but finally light drilling was selected and saved up to 60% of the original planned budget. The resulting well has a smaller diameter than O&G standards. The implications of this for CO2 storage site operation need to be studied and consideration of how drilling techniques can be optimized need to be investigated through discussion between the drill rig operators and
geoscientists who will use the core for experimentations to characterise reservoir and seal.
Although there are experiences in the light drilling for other activities such as mining and shale gas exploration especially in the USA, experiences at CO2 storage are limited to the Hontomin case. Deeper reservoirs are usually reached using oil and gas machinery, with higher cost and low flexibility.
A study will be carried out on developing the drilling rig and its associated equipment in order to reach depths of up to 2,500 m and to integrate different services, namely drilling, well completion and well logging, leading to cost savings and reducing the contracts for well services for the execution of exploratory, injection or monitoring wells.
Development of cost effective solutions to execute key characterization activities such as the drilling of wells to have a precise description of the reservoir and caprock. The light drilling activities will provide significant cost savings in the characterization phase of this demo site and other future sites onshore in Europe.