Fractures, Geothermal
Steven Ogilvie
Wettability & Recovery in Fractured Chalks

This blog addresses why wettability is important in the recovery of oil from fractured chalks.

Wettability & Recovery in Fractured Chalks
Steven Ogilvie
Natural Fracture Types in Fractured Reservoirs

There are 2 basic types of natural fractures that need to be studied when characterising naturally fractured reservoirs - whether it be a geothermal or hydrocarbon reservoir. These are extension and shear fractures.

Natural Fracture Types in Fractured Reservoirs
Faults, Folds
Steven Ogilvie
Thrust systems at different scales

This blog examines some key features of thrust systems with an example from seismic data offshore Namibia and from a hand specimen onshore UK.

Thrust systems at different scales
Fractures, joints
Steven Ogilvie
Deformation band contained Joints

This blog looks at joints contained within zones of deformation bands - how they form and if they are important or not.

Deformation band contained Joints
Fractures
Steven Ogilvie
Geomechanics approach to fracture prediction

This blog describes the value of a geomechanical approach to fracture prediction; for example thin beds often have more fractures than thick beds.

Geomechanics approach to fracture prediction

Identifying Fracture Swarms

Identifying Fracture Swarms

Fracture swarms are concentrated zones of open fractures, over which there is little or no offset. Although there are excellent outcrop examples, these structures can be difficult to identify in the subsurface. An integrated static-dynamic approach is best to successfully identify fracture swarms.

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Picking Faults in Wells

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Picking Faults in Wells

Faults are usually picked on seismic data. Given that small faults can be as important in field development, well logs should be checked for evidence of faulting.

Here we look at common fault-related explanations for thickness variations between wells and how to create a simple cumulative dip plot of bedding to detect faults.

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Deformation Bands, New Red Sandstone, Arran, Scotland

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Deformation Bands, New Red Sandstone, Arran, Scotland

Deformation bands can compartmentalise reservoirs, causing challenges for hydrocarbon production. Here we look at the New Red Sandstone on Arran which is host to an impressive network of deformation bands.

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Deformation Bands, Permian Ssts, Norway

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Deformation Bands, Permian Ssts, Norway

Deformation Bands can drastically impact the permeability of otherwise good quality reservoir sandstones. This example is from Permian Sandstones, N of Oslo in Norway. Here we look at some of it's key structures. 

Any info on the structure/d - bands of this outcrop would be appreciated. 

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Construct Fault under Rollover Anticline

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Construct Fault under Rollover Anticline

Rollover anticlines are common types of folds in extensional basins. The shape of the rollover is related to the shape of the underlying listric fault. This is useful to know as the fault may be poorly imaged.

Here we describe a simple (by hand) construction that can be performed on a seismic section - to reduce interpretation uncertainty

 

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Deformation Bands in High Porosity Sandstones

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Deformation Bands in High Porosity Sandstones

Deformation Bands are fault like structures that drastically reduce the porosity and permeability of sandstones.

Here we focus upon cataclastic (grain size reduction) deformation bands, their impact upon hydrocarbon production and exploration and some ways to predict them.