The objective of the study is to address problems related to the exploration, reservoir evaluation, and production of PdC sandstone reservoirs in the Lower Peninsula of Michigan. A total of thirty (30) wells with conventional core were analyzed and evaluated. A total of 3,428 feet of PdC conventional core has been geologically described and depositional environments have been interpreted. Particular attention is also directed at defining lithofacies which are mappable stratigraphic units identifiable both in conventional cores and on well logs.
In addition to conventional core descriptions some 250 samples were selected from productive and or potentially productive PdC sandstone units for detailed mineral, texture and pore space analysis utilizing thin section petrography, scanning electron microscopy, and X-ray diffraction. Particular emphasis was placed on the types and mode of occurrence of various diagenetic minerals and pore space types with respect to their influence on reservoir quality and log response.
Representative productive Prairie du Chien reservoir rock types were also analyzed and evaluated utilizing various advanced rock property techniques to formulate the Prairie du Chien Rock Catalog which contains geological and petrophysical properties used to evaluate the producibility of potential Prairie du Chien gas-bearing sandstones.
Study results are as follows: