2013-2014 Master in Petroleum Engineering and Operations ......eni s.p.a. upstream & technical...

eni s.p.a. upstream & technical services

Geomechanical database-Working with analogous

datasets

Chibuzor C. Onyia

San Donato Milanese 13-14-15 October 2014

2013-2014 Master in

Petroleum Engineering and Operations Management


2

Geomechanical Database- Working with analogous

datasets


Author

Chibuzor C. Onyia

Division eni S.p.A.

Upstream & Technical Services

Dept. TEPE - INGP (Well Engineering)

Company Tutors

Engr. Silvia Haiz

Engr. Elisabetta Romanin

University Tutor

Prof. Francesca Verga

Master in Petroleum Engineering 2013-2014


3

� Project Scope

� Key Concepts;

� Scratch test;

� ‘RECALL’ (what is it about?);

� Building and using Geo mechanical database;

� Challenges Faced;

� Conclusion

List of Content

Geomechanical Database: Working with analogous

datasets


4

Project Scope

Geomechanical

database; working

with analogous

datasets

Develop a new

Integrated Tool for rock

characterisation using

the data from scratch

test as an analogue.

Collect and analyse all

available past scratch

test data(UCS and PHI)

and their corresponding

acoustic log

data(SONIC) and load

into ‘RECALL’ to create

the new database.


Project Scope

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• Lack of rock mechanical

property data needed for

well bore stability

studies

• A lot of time needed for

calibration iterations

• Increased precision in

wellbore stability studies

for new wells (reduced

approximations)

• Reduced time taken for

calibrations

Past - Present Present - Future


Project scope: What we do now

66

Drilling Parameters, Well Geometry and

Drilling Events collection and analysis

Log Analysis

Rock Strength Parameter Estimation

Total Stress Estimation:

Vertical Stress

Pore Pressure Evaluation

Failure Analysis

Total and Effective Stress Estimation:

Minimum Horizontal Stress

Calibration Total and Effective Stress Estimation:

Maximum Horizontal Stress

Model application


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Drilling Parameters, Well Geometry and

Drilling Events collection and analysis

Log Analysis

Rock Strength Parameter Estimation

Total Stress Estimation:

Vertical Stress

Pore Pressure Evaluation

Failure Analysis

Total and Effective Stress Estimation:

Minimum Horizontal Stress

Calibration Total and Effective Stress Estimation:

Maximum Horizontal Stress

Model application

Where it adds value?


8

List of Content

Geo mechanical Database: Working with analogous

datasets

� Project Scope

� Key Concepts

� Scratch test

� ‘RECALL’ (what is it about?)

� Building and using Geo mechanical database

� Challenges Faced

� Conclusion


9

Key Concepts: Wellbore stability

For a good wellbore stability study, parameters like:

• Uniaxial Compressive Strength

• Friction angle

• Poisson’s ratio

• Maximum horizontal stress (SHmax)

are needed.

Unfortunately, these data are not always available from the new well leaving

us with 4 variables and a lot of uncertainty.

Using UCS and friction angle from scratch data of analogous wells removes 2

variables, reducing our uncertainty and improving the accuracy of the study.


Key Concepts: Uniaxial compressive strength

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Fa

Uniaxial compressive test: From here, the UCS or Co of the rock is

derived.(pic: Prof. Deangeli, 2013, PoliTo)

A

σa= Fa / A

Fa= axial force

A= surface area


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σa -σr

σa -σr

σrσr

Triaxial test: To derive the friction angle and UCS (pic:Prof Deangeli, 2013, PoliTo)

Key Concepts: Friction angle


Key Concepts: Mohr-Coloumb Criterion

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ϕ′

τ (Mpa)

σ′(Mpa)

βc′

σ′3 σ′1

C’- To derive the

UCS

ϕ′ − To derive the

PHI (friction angle)

β − Inclination of

the failure plane

The Mohr – Coloumb failure criterion showing the

relation ship between rock strength parameters. (courtesy: Prof Chiara Deangeli, 2013, PoliTo)


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List of Content

� Project Scope

� Key Concepts

� Scratch test

� ‘RECALL’ (what is it about?)

� Building and using a Geomechanical database

� Challenges Faced

� Conclusion

Geo mechanical Database: Working with analogous

datasets


14

Scratch Test : Basic Principles

The scratch test consists in tracing a groove at the surface of a rock

sample under fixed parameters:

– Depth of cut d;

– Cutter width w;

– Velocity v;

– Sharp or Blunt Cutter.

(pic:courtesy Epslog Belgium)


Scratch Test : Why?

� Continuous measurements with high resolution adequately

characterizes the effects of heterogeneity on the mechanical

parameters.

� Can be used to verify triaxial test results on core samples.

� Semi destructive and repeatable unlike triaxial and uniaxial tests.

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Scratch Test : How it looks like?

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The ‘WOMBAT’ tool used for scratch tests in eni

(Courtesy epslog belgium and G. Musso, PoliTo)

Sharp cutter (ductile failure - UCS)

Blunt cutter(brittle failure – PHI)

The peaks are when cracks are initiated and the abrupt

drop is associated with an unstable propagation of the

crack leading to the formation of chips

Position(mm)


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�Project Scope

�Key Concepts

�Scratch test

�‘RECALL’ (what is it about?)

�Building and using a Geomechanical database

�Challenges Faced

�Conclusion

List of Content

Geomechanical database: Working with analogous

datasets


‘RECALL’( What it’s about?)

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� Corporate database for logs in eni

� Incorporates petrophysical log data, analysis and calculations of rock

strength parameters, integrates mud logging data, well surveys and

lab test data (triaxial and oedometric) except scratch tests.

Currently used for:

� Wellbore stability analysis in eni.

� Analysis is done by applying empirical formulas.

� Gives as one of its output the shear failure gradient and the ideal

mud weight to be used while drilling.


‘RECALL’(Input data)

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(Courtesy: S.Haiz,2014, PoliTo)


‘RECALL’( How does it look?)

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User interfaceSearch interface

Rock strength parameters as output for WBS studies


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�Project Scope

�Key Concepts

�Scratch test


�Building and using a Geo mechanical database

�Challenges Faced

�Conclusion

List of Content

Geomechanical database: Working with analogous

datasets


Building and using a Geomechanical database

� A collection and conversion into ‘RECALL’ readable format of all available

scratch test data (UCS & PHI) and sonic logs.

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What is meant by ‘Geomechanical database’ :

The corporate database



� Using a specially designed integrated tool on Logscape (RECALL’s output

interface).

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How is it viewed?

The integrated analysis tool



Factors considered when designing the tool :

� Inputs required (acoustic logs, scratch data)

� Acquisition references (logs vs cores)

� Workflow simplicity and functionality

� Result format (saving the required curves).

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� Identifying critical functionalities needed (searching, depth matching,

importing and combining logs, lithologies)

� Using RECALL standard track sheets, building a logical flow of data

entry and analysis

� Defining loading conventions and creating new curves (Sonic mean,

sonic) for search optimization.

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How the tool was created?



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Scratch test

data from

laboratory

RECALL

Identify

needed

functionalities

Define

search

parameters

Build the

display tool

Acoustic

logs from

the well

Merge

Rock strength parametersOverview of the study

Sonic mean

curve

Background

User interface



� Allows for a more precise wellbore stability study.

� Shortens time taken for calibration iterations.

� Helps in saving drilling time and costs (stuck pipe, cavings, reaming)

by predicting more precise gradients.

� Ultimately, increases safety of the whole drilling process.

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What is it used for?



� Place planned well sonic and lithology on the designed semi-

automatic worksheet.

� Identify the depth range of the planned sonic being considered.

� From the statistics and lithology, search database for an analogous

well with similar parameters.

� Place the analogous sonic, UCS and PHI curves in their respective

data tracks

� Using the vertex tool, do a variable depth shift to align the depths of

the analogous and planned well.

� The UCS and PHI of the analogous can now be used for calculations

for the planned new well in another worksheet.

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Using the database/working with analogues:



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Insert the offset

well lithology

Place sonic for the

offset well and select

zone of interest

Offset well sonic

statistics for search

optimization

Analogue sonic is

inserted here after

searching

UCS and PHI of the

analogue well from

database

Lithology search can

be done



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The tool showing the different tracks, zones, planned sonic and output.


List of Content

Geomechanical database: Working with

analogous datasets

31

�Project Scope

�Key Concepts

�Scratch test


�Building and using a Geomechanical database

�Challenges Faced

�Conclusion


Challenges Faced

� Data collection and model validation

� Defining and Refining the search parameters

� Simplifying the tool

� Depth matching

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List of Content

Geomechanical database: Working with

analogous datasets

33

�Project Scope

�Key Concepts

�Scratch test


�Building and using a Geo mechanical database

�Challenges Faced

� Conclusion


34

Conclusion

• Database dedicated to rock strength parameters;

• New semi-automatic tool for analysis of the database.

• Quicker model calibration and prediction while drilling

Add-on:

• A user guide developed to optimize usage of the tool.

• Updating scratch database as soon as the

experiments are done in the laboratories to

prevent gaps making the database more robust.

• Refining the search parameters as the database

grows and more data parameters are added.

• Using other logs.

What next ?:

Main Results:


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Acknowledgements

To God Almighty, without whom this one year would have

been impossible.

To eni s.p.a upstream & technical services management for

the permission to use their data and present this work.

To my tutors and dear colleagues in TEPE-INGP for the coffee,

support, attention and advice.



Questions???

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2013-2014 Master in Petroleum Engineering and Operations ......eni s.p.a. upstream & technical...

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Transcript of 2013-2014 Master in Petroleum Engineering and Operations ......eni s.p.a. upstream & technical...