RE: Charlatans Abound....19 Jan 2020 22:27
Fractured basement hydrocarbon reservoirs are recognized worldwide, but they are relatively poorly understood and underexploited (Trice, 2014). In such plays, oil migrates laterally from an organic-rich source rock into a subsurface paleohigh of fractured crystalline basement, forming a so-called “buried hill” trap (Biddle and Wielchowsky, 1994). The seal is provided by a blanketing sequence of clay-rich mudstone.
Given the very low matrix permeability of most crystalline basement rocks, oil and other associated fluids are transported and stored via well-connected fracture systems. The geological characteristics of these fracture systems are not well understood because they are poorly imaged in seismic reflection data, and core samples are sparse. Critically, the processes involved in fluid transport and storage are also uncertain, although it is often assumed that migration into the basement high is primarily a passive process driven by the relative buoyancy of hydrocarbons following maturation at the source (e.g., Trice, 2014).