Halfdan

Well Production and Technology

We are developing new technology that ensures well stability and enables maintenance of the outer parts of wells, which was previously impossible. The design of oil wells in the Danish North Sea presents significant challenges to structural integrity and utilisation of the well. These wells are up to 10 km long horizontally, making access to the far end for ongoing maintenance extremely difficult.

The research takes place in two independent themes: improved cement and extended reach with coiled tubing. They both contribute to maintaining the efficiency of Danish oil production, which stands out as being some of the most energy efficient in the world.

Improved cement 

When drilling wells, cement is used to insulate and support production pipes, and when this cement solidifies, it cracks. We are developing a cement that can repair these cracks itself, by embedding a bacterial culture into the cement that forms calcium carbonate, or limestone where the cracks occur.

Very few living organisms can survive the extreme acidity, salt, pressure and temperature conditions that the cement offers, and at the same time the bacteria must have sufficient nutrition to survive. Therefore, we have tackled a major challenge by identifying and isolating promising bacteria that we are testing for commercial use.

Read more about improved cement 

Extended reach with coiled tubing

At the same time, we are developing methods to reach the end of the very long horizontal wells. With the current technology we can only reach approx. half way out with coiled tubing, a hollow metal tube used for maintenance tasks, which means it will be difficult to solve problems with scaling and water production in the outer parts of the well. We are therefore working to develop a substance that can reduce friction as the operator pushes coiled tubing down through the well. Our mathematical models indicate that a reduction in friction with the right substance will allow access to depths not previously possible.

Read more about the work on extended reach   

Collaboration

Our research becomes a reality through collaboration of different disciplines and expertise. A good example is the work on self-healing cement, where researchers with a high knowledge of bacteria collaborate with researchers who have a great deal of knowledge about cement, and with other researchers who have a great knowledge of how to test cement. Only by combining expertise in this way do we achieve results that can make a difference in production.

Collaboration partners

Improved Sweep in Deep Tor

Maiya Medetbekova
Meet Maiya Medetbekova PhD student at DHRTC and hear about her research within radial-jet drilling in the North Sea.

Self-healing Cement

Søren Dollerup
Meet Søren Dollerup Nielsen, PhD student at Aarhus University and hear about his field of research self-healing cement.

Contact

Kitt Anita Ravnkilde
Principal Programme Manager
Centre for Oil and Gas - DTU
+45 93 51 13 91
https://www.oilgas.dtu.dk/english/research/work-programmes-and-research/wpt
3 DECEMBER 2020