# Determination of the Overburden Permeability of North Sea Chalk

• Meysam Nourani
• Aurelien Gabriel Meyer
• Hans Jørgen Lorentzen
• Lykourgos Sigalas
• Mirhossein Taheriotaghsara
• Dan Olsen
• Lars Stemmerik
Technical Note

## Introduction

Absolute permeability is a key reservoir parameter and is particularly vital for reservoir management during the reservoir life cycle. The basic law of fluid flow in porous media is Darcy’s Law. The Darcy equation demonstrates that the velocity of a fluid in a porous medium is inversely proportional to the fluid viscosity and proportional to the pressure gradient (Ahmed and McKinney 2005):
$$Q= - \frac{{KA}}{\mu }\frac{{{\text{d}}P}}{{{\text{d}}L}},$$

## Keywords

Porosity Absolute permeability Overburden permeability Pore compressibility Permeability modulus North sea chalk

## List of Symbols

$$Q$$

Volumetric flow rate

$$K$$

Absolute permeability

$$A$$

Cross-sectional area of flow

$$\frac{{{\text{d}}P}}{{{\text{d}}L}}$$

$$\mu$$

Fluid viscosity

$$\sigma$$

Effective confining pressure

$${K_{\text{k}}}$$

$$a$$

Coefficient (Slope)

$${K_{\text{b}}}$$

Coefficient (Intercept)

$${K_{\text{c}}}$$

Fitting parameter

$$\varphi$$

Porosity

$${C_{\text{p}}}$$

Pore volume compressibility

$$\gamma$$

Permeability modulus

$$n$$

Number of samples

$${K_{\text{g}}}$$

Measured absolute permeability

$$\Delta P$$

Difference pressure between the overburden sleeve pressure and ambient sleeve pressure

$$P$$

Pressure

## Notes

### Acknowledgements

The authors are grateful for the financial support by the Centre for Oil and Gas-DTU/Danish Hydrocarbon Research and Technology Centre (DHRTC). We are also grateful to Niels Springer, Niels Hemmingsen Schovsbo, Margrethe Thorup Nielsen and Louise Ponsaing Lauridsen for their highly constructive comments and recommendations.

### Funding

This study was funded by the Centre for Oil and Gas-DTU/Danish Hydrocarbon Research and Technology Centre (DHRTC).

### Conflict of interest

The authors declare that they have no conflicts of interest.

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## Authors and Affiliations

• Meysam Nourani
• 1
• Aurelien Gabriel Meyer
• 2
• Hans Jørgen Lorentzen
• 1
• Lykourgos Sigalas
• 1
• Mirhossein Taheriotaghsara
• 3
• Dan Olsen
• 1
• Lars Stemmerik
• 2
1. 1.Geological Survey of Denmark and Greenland (GEUS)CopenhagenDenmark
2. 2.Natural History MuseumUniversity of CopenhagenCopenhagenDenmark
3. 3.Center for Oil and GasThe Technical University of Denmark (DTU)CopenhagenDenmark