We report the effects of porosity and total organic carbon (TOC) content on the mechanical behavior of organic-rich chalks, based on laboratory measurements. The organic-rich chalks are from the Senonian Ghareb and Mishash formations. This deposit is an immature oil-prone source rock, about 300 meters thick, situated at shallow depths (several hundreds of meters) in the Shefela basin in central Israel. The study is based on core data collected from the Zoharim borehole.
Three main phases comprise the bulk volume of this rock:
carbonate mineralogical phase (predominantly calcite);
pores (mostly saturated with brine); and
solid organic phase (type IIS kerogen).