Geology & Geophysics

Bottom-up meets top-down

If there is one positive aspect to this day and age, it is the ability to form solid working relationships even when people are living at opposite ends of the…

Flame structures

Outcrops remind us of the risks of applying a layer-cake approach to correlating well data. Turbidite lobes pinching out, channels abruptly transitioning to floodplain deposits or carbonate platforms only developing…

Energy is politics, is community, is pride

My dear friend William invited me last month to Brecon, mid Wales. Another dear friend, Ian, lives in Penarth, just outside Car­diff, south Wales, so it made perfect sense to…

The evolution of fault interpretation

Before the ad­vent of 3D seis­mic data in the 1980s and 2D seismic in the 1970s, sub­surface geologists typical­ly depicted or interpreted faults as vertical or nearly vertical. Consequently, these…

What is a good source rock?

I recently worked in a well-es­tablished basin with proven hy­drocarbon accumulations. To my surprise, all reports and published papers routinely talked about local source rocks with barely 1 % Total…

Ripples and plane beds

The Cutoff Formation, currently exposed in the Guadalupe Mountains in Texas, USA, was deposited over a drowned shelf margin in Permian times. The name of the formation is derived from…

A Libyan core in Scotland

Issue 3 came very close to the wire, and it was a marathon! Most people expect this magazine to appear at regular two-months intervals, but our agenda is very much…

Unlocking fractured basement reservoirs

Fractured basement reservoirs, often igneous or metamorphic rocks like granite or gneiss, contrast with conventional sedimentary reservoirs. Without primary porosity, they depend on fracture networks for hydrocarbon storage and flow.…

Coring process step by step

We often talk about core being the only ground-truth data from the subsurface, but how is core cut from a well at kilometres depth? With many geologists being stuck to…