Stylolites
Stylolites are burial diagenetic features that occur in many reservoirs, but are particularly abundant in Paleozoic dolomites and limestones. They are recognized as seams or films of insoluble residues that record removal of carbonate rock by pressure-solution processes. Stylolites can affect reservoir performance and reservoir compartmentalization by forming barriers to fluid flow.
Red River dolomites and limestones within the study area display a complete range of pressure-solution features, ranging from microstylolites to high-amplitude stylolites, wispy seams, and individual or isolated solution seams. Many of these types of pressure-solution structures modified primary depositional and faunal structures (cryptalgal laminates and burrows) into stylolite-bounded fabrics which have distinctive laminated, nodular, and mottled appearances in subsurface cores. During and after oil migration into structural traps, stylolites commonly form at oil-water transition zones or in beds with high water saturations. This may account for some of the reservoir compartmentalization in Red River intervals.