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Permeability Measurements

Introduction

There are many different methods for estimating permeability of the surface. For simplicity, three (3) are listed below:

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  • Pressure Transient Analysis (PTA)

  • Rate Transient Analysis (RTA) or Well Production Analysis (WPA)

Comparison of Permeability Measurements

The various approaches to measuring permeability have different assumptions, and therefore they can produce different results.

In the example below, permeability determined from PTA, RTA (or WPA) and the mean (or average) from a test core are shown for a project in Venezuela. The conclusion drawn by Blasingame [2014] was that the various methods of estimating permeability due not appear to be correlated. For instance, kPTA values were higher than kRTA values.

Core scale heterogeneities may have no impact on overall reservoir performance, and attempts to correlate small-scale heterogeneities are likely to fail [Blasingame, 2014].

image-20230902-023452.png
From T. A. Blasingame

Potential Areas of Conflict

The table below, reproduced from Blasingame [2017], is a list of potential conflicts with permeability and other related parameters. There can easily be two or more sets of data representing the same property.

Porosity

  1. Core

  2. Open-Hole Logs


  1. Core Scale

  2. Reservoir Scale


  1. High Confidence

  2. High Confidence

Permeability

  1. Core

  2. Open-Hole Logs

  3. Pressure Transient Analysis


  1. Core Scale

  2. Reservoir Scale

  3. Reservoir Scale


  1. High Confidence

  2. Low Confidence

  3. High Confidence

Reservoir Pressure

  1. Formation Wireline Tester

  2. Pressure Transient Analysis


  1. Reservoir Scale

    1. Reservoir Scale


  1. High Confidence

  2. Medium Confidence

Initial Saturations

  1. Core

  2. Open-Hole Logs

  3. Cased-Hole Logs


  1. Core Scale

  2. Reservoir Scale

  3. Reservoir Scale


  1. Medium Confidence

  2. High Confidence

  3. Medium Confidence

End-Point Saturations

  1. Core

  2. Open-Hole Logs

  3. Open-Hole Logs

  4. Cased-Hole Logs


  1. Core Scale

  2. Swir - Reservoir Scale

  3. Sor - Reservoir Scale

  4. Sor - Reservoir Scale


  1. High / Medium Confidence

  2. High Confidence

  3. Medium/Low Confidence

  4. High/Medium Confidence

See Also:

References

  • T. A. Blasingame “Formation Evaluation and the Analysis of Reservoir Properties” , Texas A&M University, Course P663 -14 B, 2014.

  • T. A. Blasingame “Formation Evaluation and the Analysis of Reservoir Properties” , Texas A&M University, Course P663 - 17B, 2014.