Tight Reservoir Development

Improved recovery from the tight Lower Cretaceous reservoir

We work towards improving the recovery of oil from the tight Lower Cretaceous reservoir. The research improves the fundamental understanding of the effects of oil production from a low permeability reservoir.

Historically, oil production in the North Sea has primarily come from the Upper Cretaceous reservoirs, providing extensive knowledge about these layers.  In order to increase the recovery from the less permeable Lower Cretaceous layers, new research is needed.

Low-permeable reservoirs lead to new challenges

During the Lower Cretaceous a larger, varying, supply of clay was deposited than during the Upper Cretaceous. As a result the Lower Cretaceous reservoir alternates between chalk, marly chalk, marlstone and claystone. The presence of clay particles may restricts fluid flow through the rock, cf. the illustration below. 

Small permeability

Figure 2.

An important part of the research is to identify where hydrocarbon volumes are located in the Lower Cretaceous and their properties. In addition, we are also working to understand how the reservoir reacts as oil is produced. For example, how fractures in the rock change the flow patterns and what the consequences are as the rock compacts with the removal of fluid and thus pressure from the reservoir. With a better basic understanding of the reservoir, we can constrain the uncertainty of our predictions and better estimate where it makes sense to place new wells.

Energy efficient oil extraction

Denmark is a global leader in minimizing the carbon footprint of its oil production. Among the Danish fields, the Valdemar Field stands out as having the lowest emissions per oil barrel produced. The natural properties of this Lower Cretaceous field allows for production by compaction without the need for additional energy expenditure using other enhanced recovery technologies allowing more sustainable, higher efficiency production.

Data and Results

At this stage in the programme, we constantly receive new research results helping our industrial partners to improve their oil production efficiency in the Lower Cretaceous. We create everything from conceptual models to basic descriptions of the reservoir and geomechanical tests of how the rock responds to various methods. Results will continue to come in over the next years as the research projects mature and complete.


Collaborating with partners from across academia and industry with an interest in the Lower Cretaceous emulates the way industry works. Generating synergies between the various professional groups to reach our aim of multidisciplinary research results directly applicable to industry.

Since initiation of the programme, our dialogue with industry, through workshops and other interactions, has identified the main challenges related to the Lower Cretaceous reservoir. Ongoing industry involvement has ensured that we tackle the most pertinent problems to create value in production.

Collaboration partners

Learn more about what two of the researchers are working on in the work programme, Tight Reservoir Development.


Ulla Hoffmann
Programme Manager
Centre for Oil and Gas - DTU
+45 93 51 13 60