High permeabilities, despite low porosities (typically 5-10%), in the Mirador Formation (Eocene) reservoir sandstones at Cusiana giant oilfield are attributed by Warren and Pulham (2001) to mineralogical maturity, large grain size, and a simple diagenetic history involving only quartz precipitation (i.e. no secondary porosity). However, Warren and Pulham (2001) do not explore the reasons for this simple diagenesis, so their interpretation lacks predictive power. Why was there no carbonate cementation, unlike many other quartz arenites worldwide (e.g., Schmidt and McDonald 1979)? A likely control is the depositional and post-depositional salinity of the pore water.

...

Secondly, retention of primary porosity...

First Page Preview

First page PDF preview
You do not currently have access to this article.