Geological Characterisation of Early Palaeozoic Mudrocks, Lublin Basin, South-East Poland
McLay, Samuel A.
Recent exploration activity within Poland has been dominated by emerging shale gas plays contained within Early Palaeozoic source rocks. Chevron has acquired acreage within the Lublin basin of south east Poland to test the potential of some of the plays. A key component of this assessment is the geological characterisation of different mudrock types and the understanding of small-scale heterogeneity accessible only from detailed core observations and measurements.
An extensive analysis programme has been carried out on conventional cores and rotary sidewall cores (RSWC) acquired as part of an initial exploratory drilling programme. Mudrock lithofacies defined from visual inspection include laminated mudstones, carbonaceous claystones and carbonate mudstones. Quantitative X-Ray Diffraction (QXRD) mineralogy is combined with scanning electron microscopy (SEM) and thin-section petrography to define the textural and compositional heterogeneity within cored intervals. Although many of the facies initially appear homogeneous their complexity is revealed by detailed core analysis and is emphasised by the integration of different data types.
Successful exploration and exploitation of prospective shale gas resources in Poland will depend on the recognition of mudrocks types as well as their vertical and lateral distribution. Insights gained from rigorous core observations and precise measurements are crucial in explaining larger-scale trends within the Lublin basin and ultimately the high-grading of acreage based on initial exploration results.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013