Correlation energy between surface and borehole stations at the Valhall field

Acknowledgements

We thank to Olav Barkved for helpful discussions and suggestions. Thanks to Joe Dellinger for discussions on the mechanism of coherent energy between surface and borehole stations. We gratefully acknowledge to BP and the partners of the Valhall field (BP Norge A/S and Hess Norge A/S) for permission to publish this paper.