download Dr Gibbs presentation - Finding Petroleum

The structural geology experts

www.mve.comMidland Valley

Innovation in thinking……… or more technology? What makes the difference?

Alan Gibbs



1980

Sections like these are not valid

Structure makes the difference to E&P success

1930



Validate by Reverse Modelling

Can we put the faults back together ?



Software adds value to expertise 1983 ---

Consistent reproducible

approachnot possible with pencil technology



Software adds value to expertise:

Reproducible workflows

Use more data

Faster cycle times

Model systems too complex for “pencil”



The Time dimension - kinematic modelling

Mass and volume balance through geological time

-

Unique capability to interrogate data and concepts



DFN model from elastic deformation model

Well bore fracture data orientation statistics used to constrain model predictions

Fracture set 1 poles

DFN of 2 Fracture sets, Fracture set 1 visualisation colored cyan



Data + Interpretation in restored space



Take the application to the data



Reduces cycle time and error

Fucoid

Durness



Symptoms of Structural uncertainty

• Target error (too high / too low / wrong place / absent)

• Surprise (fault / boundary in unexpected place)

Prewell

fault model

Actual fault

position

Fault position

uncertainty

(root cause)

Prewell

target

Surprise fault

penetration



Cost of structural uncertainty in drilling

NPT - stuck pipe due to drilling into

wrong place (e.g. fault / pressure)

NPT – Geological

sidetrack, decided we

were in wrong place

NPT – lost!! Crisis technical work,

partner meetings, new FWD plan

ILT – Reduced RoP while

geologists catch up with

new structure

40 day well becomes

60 day well: 50%

increase in day rate

costs and 20 day

production delay.

We

ll P

en

etr

ati

on

Days



Success or still a way to go?

Limited by technical culture and the nature of geoscience problems

Technology means we can be wrong faster and with less effort



Classic approach:

• Create and defend “best model”

• until “surprises” force a new interpretation

Sequential realisations

Costly

Inefficient



Odin project uses synthetic models to recreate data and interpretation sets to test

subjective spread in interpretation

Synthetic “reality”

Synthetic seismic

The Odin Project



The Odin Project



The Odin Project

21% of geoscientists produced the modelled answer

Interpretation Types



Yes, we are that bad!

Out of 500 industry interpreters 400 weren’t

even in the ball park

What is the way forwards?

Question can turn weakness to strength?



ExpertiseExperts and non-experts

23%27%

35% Bond, et al. (2008) GSAToday

445 315 184



Techniques

Effective experts

use lots of techniques.

100%

79%

67%

23%18%

35%



Call yourself an expert?

Effective experts

used specific techniques –notably thoughts about the geological evolution.

35%

94%

44%51%45%37%

10%



Everyone can be an expert?

27%

87%

37%40%

7%

38%30%

non-experts



Everyone can be effective

by using multiple techniques to query the data and,

applying specific validation techniques.



More than one answer?

Perhaps other solutions honour the data.

If we had given the participants a choice of interpretations that included the „correct‟ answer, would the percentage of correct concept choices have been significantly higher?



It’s an inverted roll-over

No, it’s a hanging wall anticline with growth strata

It’s……. time for coffee

There‟s always room for a different interpretation

Unique solutions are rare

„The Human Element‟



Current culture is to create the rightinterpretation and model

3D Seismic

Framework modelling

Precision conceals real level of uncertainty



It is part of the interpretation process to generate multiple models

From the 1980‟s



Models are just that - models

• At some level they are always wrong

• Geological problems are massively under-constrained

• No single deterministic answer



Multiple scenarios allow us to

ask before the “surprise”:

What would change the Decision?

What would change the Outcome of that

Decision?

What are the tipping points?



Identifying Tipping Points

ParametersElastic properties

Geomechanical

Geometric

Models

Processes

Analysis &

Comparison

Cross plots

Pseudo wells

Differences

Residuals

Co-visualisation

Attribute

mapping

Restore, seds, fracs,

hydro systems

Restore revise

interpretation cycle

Understanding the impact of technical uncertainties

Single model

Multiple models

Common process

Multiple processes

Sensitivity



Scenario Analysis

North Sea

turbidites

Entry and source from crestal collapse feature

Erosive flowNon erosive flowNarrow transfer

Geometry of the sediment transfer channel controls reservoir distribution



Scenarios

Range of geological possibility

Assess and quantify uncertainty

Identify range of potential outcomes

Critical tipping points for the decision

-- Geological probability impacts risk



Technology gets us where the pencil won‟t go.

As much as we can get, please!

Structural Balancing reduces risk

Thinking scenarios reduces surprise



The model is

just a model

Nature is

more

perplexing

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