Oil & gas companies strive to reduce risk; exploration and production drilling is an expensive, high risk business. One way to reduce risk is to collect more information from geological sequences and improve the geological model.
Cuttings (drill bit-induced rock chips) and diamond drill cores are generally the only samples available to the geologist to directly determine the nature of the sequence through which the drill bit has penetrated. As a result, great importance is often placed on documenting cuttings and cores as accurately as possible, both at the time of drilling and post-drilling. Characterizing down-hole lithological variation in a reservoir sequence is a critical requirement in exploration and production wells, and mineralogical and petrographic studies underpin the fundamental understanding of reservoir and seal characteristics. Traditional optical, SEM, EPMA and XRD analysis methods are well established and widely used within the industry.
Automated Mineralogy offers a complementary level of cuttings and core analysis - providing fast, direct analysis with reliable statistics. The automated data collection achieved by FEI's
QEMSCAN® solution allows hundreds of cuttings, and large areas of core (up to 10 x 10 cm), to be analyzed within practicable time frames. The resulting high resolution digital images allow classification of cuttings and cores into quantitative lithotypes. This classification is based on mineralogy and micro-texture. Suspected cavings can be digitally removed and the data renormalized caving-free.
Applications include: down hole mineral and lithotype logs which allow improved calibration and interpretation of geophysical wireline logs; cross-well correlation; improved source, seal and reservoir characterization; in-situ heavy mineral provenance studies which preserves textural context and enhances interpretation.
A variety of sample types can be accommodated within the QEMSCAN® system, including: washed and unwashed cuttings, conventional diamond drill cores, core plugs, core trims (off-cuts), sidewall cores, conventional hand-specimens and pipe-tubing deposits. Samples can be presented to the system in various forms: as polished blocks (1inch/30mm), polished thin-sections (standard), rough surface cores (diamond saw cut surface), or as particles on carbon tape (double-sided SEM tape).