Drilling through granite in an extremely steep angle
Equinor is developing an infrastructure to transport Carbon Dioxide by ship from capture sites allover to a terminal in western Norway, for intermediate storage.
From here, a pipeline is laid across the seabed to an underground reservoir about 130 kilometers off the Norwegian coast.
At the receiving terminal, our 250 ton rig was setup with specialized tools to drill through the granite bedrock. Here, we make the connection between the land and sea sections for the Carbon Dioxide pipeline. This has been completed by means of horizontal directional drilling, or so-called HDD, where we start on land and end the drilling 260 meters below the surface of the fjord.
What makes this tunnel special, in addition to the challenging ground conditions, is the steep entry angle of 44 degrees. Our experienced Engineering team designed a special frame that allows the drilling rig to be placed at a steep angle and still be able to absorb all the great forces and vibrations that occur when drilling in the Norwegian granite.
Renewable all over
Before works to deliver the project at the site started, a significant amount of attention was invested in the detailed design and engineering of the drilling equipment, tooling and the specific drilling process. During the drilling process, many tests and trials were carried out in order to verify the various parameters, and make adjustments if necessary, so we learn and incorporate continuous improvement.
An important element in this project is the power supply for the drilling equipment itself. It runs entirely on electricity supplied by Equinor. By making a number of adjustments to the equipment, we can run a more energy-efficient project this way. This quickly results in a saving of around 2000 liters of diesel per day.
Norway generates 98% of its electricity from renewable sources, with energy provided to the rig through these sources, this allows for massive carbon reductions through the construction phase and provides environmental benefits for all.