Review of selected non-seismic methods for onshore hydrocarbon exploration in Denmark. ALTKUL Project Report Part 1

As geophysicists not normally working with seismic data acquisition, we have often noted the total reliance on seismic data in the oil and gas industry, even when other types of geo-physical data seemed helpful and useful to us. We are aware that nothing can compete with e.g. modern 3D seismic surveys, and we applaud the detail, accuracy and understand-ing that can come out of such data. On the other hand, working mostly in the mineral sector, we often have to do with far less.

Perhaps therefore, our interest was piqued at once we were approached with the wish for a look at alternative methods for onshore exploration after hydrocarbons in Denmark. In Na-tional Parks, near vulnerable buildings etc., it is often not possible to get the necessary permissions for seismic work – are there then other methods that can help, providing sufficient data to make a decision without access to seismic data? At conferences and over coffee we hear about these alternative methods, we know some of them should work, but often claims are made that seem unreasonable. In short, we decided to take on the study, with the hope that we could learn something new from those cases, where alternative methods had been used, and perhaps suggest some approaches for non-seismic explora-tion in onshore Denmark.

Some of the results are laid out in this report. We were asked by the client to concentrate on seven techniques or methods, including some methods that are familiar but also some that seem farfetched. Furthermore, some sorting would have to be carried out, focussing on matters especially relevant for the Danish area. It has been a very interesting undertaking, and we have been far around. Our review can hopefully serve as a starting point for interested readers, and we hope that it will help clarify some issues for the non-experts in non-seismic methods. Can data be generated that will allow an exploration manager to make a go/no go decision for drilling a possible target without access to seismic data? Well, that question probably cannot be answered in general. It will depend very much on the precise scenario.

We have kept this report as non-technical as we could for an easy read. In Part 2 of the project report, released November 2012, the detailed results of a realistic test of magneto-tellurics at Tønder will be presented.