Diagenetic and Provenance Studies
Detailed petrographic analysis of core samples to identify key factors relating to reservoir quality.
Reservoir quality porosity requires the following:
moderate or better sorting, early quartz overgrowth cement, and development of secondary pores. Diagenetic studies summarize everything that has happened to the sediments diagenetically from deposition to drilling, based largely on the cross-cutting relationships of the cements/overgrowths, grain dissolution, compaction, and rimming/coating cements. We typically include a chart depicting the relative timing of all the identifiable diagenetic events. This data may then be correlated with client-supplied paleologic and/or radiometric data for event timing.
Maximum reservoir quality porosity requires preserved bedding, in addition to the three criteria above.
Factors contributing to low permeability:
Depositional matrix clay, laminations, and stylolites
Burrowing which results in poor sorting
Common to abundant authigenic clay
High mechanical and chemical compaction
Depositional environment determination is a critical factor for assessing play trends, maturity predictions, field correlations and other geological assessments.
Provenance is the reconstruction of the history of sediment movements over time. Provenance studies of clastic sediments are important for the determination of trends, potential organic content, and to restore the tectonic, paleo-geographic, and paleo-climatic history of the sediments.
Our diagenetic studies include a general diagram showing the paragenetic sequence(s), which illustrate the relative timing of different cementation events and other events such as grain and cement leaching and deformation.