AAPG Conference Fieldtrip Report

As the lights went out on the AAPG International Conference and Exhibition in London late last year, the field trip leaders reported back their experiences from visiting classic geology localities in the United Kingdom and Europe.

With ICE in one of the most iconic European capitals, the organization committee wanted to shape an ambitious field trip program that would look beyond the British Isles. Against all odds dictated by the unfavorable state of the industry, three field trips accompanied from start to end the success of ICE in London, two of which are detailed below.

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Susie Daniels, Jonny Imber and Michael Mawson reported from the Fractured Reservoirs field trip in northeast England:

Experiencing an authentic (mild but damp) English autumn, 13 professionals from six different companies visited fractured reservoir localities in northeast England. We examined fracturing in both comparatively homogeneous and heterogeneous sequences, the shale rich Lower Jurassic (Lias Group) Whitby Mudstone Formation and carbonates of the Upper Permian (Zechstein Group) Roker Formation, respectively, and considered the impact of faults and fractures on fluid flow.

With a total organic carbon approaching 20 percent, the Jet Rock of the Whitby Mudstone Formation in the Cleveland Basin represents source rock/shale oil reservoirs and seal units, and is an analogue for the less well-exposed Weald Basin in southern England, and the time equivalent Posidonia Shale in the Netherlands and southwest Germany. Exposures on clean, wavewashed platforms and in cliff sections provided the basis for discussions on the lateral and vertical variation in natural hydraulic fractures, mechanical boundaries and interaction between fractures.

The unabating rain proved too much for the final outcrop, but didn’t dent enthusiasm for evening dialogue, which began with seismic sections and well logs in preparation for the Zechstein carbonates.

The Zechstein carbonate rocks of northwest Europe are hydrocarbon reservoirs from the northern North Sea to Poland, and include some of the oldest fields to have been discovered and produced. The spectacular exposures of mainly shallow water (platformal) carbonates in northeast England have undergone varying diagenesis, including dramatic collapse brecciation caused by evaporite dissolution during uplift and exhumation. The variation in fracture properties linked to facies, faulting and evaporite dissolution were evident and could have borne much longer examination in the County Durham sun.

Overall the trip benefited from the expertise, enthusiasm and interest of the participants, providing much discussion amongst the group.