In the study area, Ratcliffe oil is typically entrapped within dolomitized burrow-mottled mudstones and wackestones. Dolomites are fabric preserving and microcrystalline to cryptocrystalline.
Intercrystalline porosity is poor to fair and associated permeability is the same.
Vuggy and channel pores commonly occur within dolomitic strata and possibly developed during burial diagenesis. Late-burial dissolution associated with chemical compaction, maturing hydrocarbons, or hydrothermal processes may be a common control in Ratcliffe reservoir development. This evaluation has shown that Ratcliffe dolomitic reservoirs were subjected to burial diagenesis which modified pre-existing reservoir conditions and both improved and reduced porosity and permeability. Anhydrite and calcite replacement are locally present in Ratcliffe reservoirs. These occluding and diagenetic minerals decrease both porosity and permeability.