[bestintxas]

Yeah, I recall working some Total-operated properties years ago where some production occurred from them.

Here’s what I found

http://www.geoscience.co.uk/assets/file/Reservoirs%20in%20Fractured%20Basement%20Ver%2010_JCG.pdf

[thackney]

Thanks for that, I’m going to read it in more detail.

At first glance I see:

Basement reservoirs are a subset of naturally fractured reservoirs, and various definitions of ‘basement rocks’ exist (see for example Landes et al 1960, P’An 1982, Koning & Darmono 1984, Aguilera 1995c and North 1990). The definition that we think is most appropriate in the context of hydrocarbon exploration is that of Landes et al (1960):

any metamorphic or igneous rock (regardless of age) which is unconformably overlain by a sedimentary sequence

North (1990) however took a different view, considering basement rocks to include those of sedimentary origin if they have little or no matrix porosity. This definition would be quite wide including fields hosted, for example, in the Cambro-Ordovician quartzitic sandstones of Algeria.

- - - - -

This seems to tie the sourcing of the material to the sedimentary layer. If that layer lies on natural fractured granite, liquids from the sedimentary layers are going to be in the granite fractures.

But now I’ve got something new to read during lunch. I just got back from the local plant and you’ve saved me from pretending to be social with my co-workers.

Cheers!

[thackney]

Thanks for that, really. I’ve got more reading to do but it appears all are sourced from sedimentary zones.

Page 18 - Petroleum ages in Russia extend over a 1000 million year time period with source rocks ranging from late pre-Cambrian to Miocene.

I didn’t realize there was production sourced from such an early period. Thanks again.