Sample collection is usually made by wellsite sample catchers at 30-foot intervals. They can be more closely spaced as necessary. A reference sheet of preferred sample catching methods is available for download here.
Primarily, samples are prepared at Paleo Data Inc.’s lab or on the wellsite from drill cuttings collected by sample catchers from drill rig shale shakers. Techniques used to prepare and process samples will vary according to rock type, age of section, preservation within the sediment matrix, drilling mud type (water-base vs. oil base), presence of drilling additive, etc. At Paleo Data Inc., sample quality is assessed by paleontologists on an ongoing basis. Adjustments are made to the process to obtain the highest quality sample possible. Typically up to 4,000 feet of cuttings at 30-foot intervals can be processed in a day. Occasionally, for precise sample placement and analysis, Paleo Data Inc. will process sidewall and conventional core samples at exact depths. The preparation technique usually involves a four-step process: Detergent emulsification, soaking, sieve-washing and drying. Sample extractions are taken during foram processing for nannofossil smear slide preparation.
Paleo Data Inc. micropaleontologists examine the washed residue samples by size fraction under Leica/Wild stereozoom microscopes. All taxa observed are digitally documented and counted (quantitative data collection), or assigned to one of 13 abundance groups (semi-quantitative). Prepared smear slides are examined concurrently with microfossil samples utilizing a Zeiss Axioscop or Axiolab microscope with a mounted digital camera at magnifications of either 1,000x or 1,260x. A minimum of 400 fields of view are examined to ensure a complete assemblage is observed and incorporated into the data.