Pore Pressure Methods of Analysis, a course written and taught by Chris Fletcher

I am offering a course on Pore Pressure and Fracture Gradient Methods of Analysis designed for engineers and geoscientists that review for acceptance and use PPFG products. I offer the course to companies that want their well planning and operations staff to understand how PPFG models are generated.

Please review selected sections of the course posted as articles on my page.

This course was written to give engineers and geoscientists that use PPFG products in well planning and operations a detailed description of how PPFG models are generated, enabling them to more effectively review and use the model results. The intent of the course is to sufficiently educate the users so they can ask more focused questions when reviewing the product and assess the plausibility of answers to their questions, as well as develop their individual range of uncertainty when applying the results of the PPFG models to make well planning and operational decisions.

Pore Pressure and Fracture Gradients for Engineers and Geoscientists

Author Chris Fletcher

Outline for course

Day 1

Introduction, Purpose, and Scope

1.0 Description of Clastic Deposition Geology

1.1 Erosion, transport and deposition of clastics

1.2 Clay particle size distribution

2.0 Description of Pore Pressure in Shale

2.1 Clay particle deposition and burial diagenesis characteristics

2.2 In-situ water flow characteristics in shale

2.3 In-situ water flow restrictions related to pore pressure gradient

3.0 PPFG Modelling Principles

3.1 Terzaghi principle

3.2 Log responses related to pore pressure gradient

3.3 Centroid effect in permeable formation members

3.4 Model calculation reference heights

Day 2

4.0 PPFG Modelling Process

4.1 Resistivity, sonic, and interval velocity responses with pore pressure gradient

4.2 Seven-step model process (Calculate OBG, Select shale intervals, Define normal compaction trend, Calculate pore pressure gradient, Calculate effective stress ratio, Calculate fracture gradient, Calculate permeable formation hydraulic heads

4.3 Eaton and Bowers models for resistivity, sonic, and interval velocity

4.3.1 Eaton Resistivity Model

4.3.2 Eaton Sonic Model

4.3.3 Eaton Interval Velocity Model

4.3.4 Bowers Sonic Model

4.3.5 Bowers Interval Velocity Model

4.4 Matthews and Kelly fracture gradient model

4.4.1 LOT analysis

4.4.2 Calculate effective stress ratio

4.4.3 Calculate Fracture Gradient

5.0 Offset Well Analysis (example applying above principles and process to offset well)

5.1 Seven-step process applied to offset well

5.2 Derive interval velocity parameters to be applied to project location

6.0 Prospect Location Analysis (example applying offset well analysis to prospect location)

6.1 Seven-step process applied to project location

6.2 Apply model parameters and definitions to generate final results and ranges of uncertainties

7.0 Discussion with attendees

Day 3 (optional)

8.0 Conclusions and Discussion

9.0 Demonstration of PPFG analysis with software

10.0 Review of client current or previous project(s)