Shell Well Story

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Well Proposal and Well Monitoring

Oxford University, 24th, 31st January, 2003


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Sessions Structure

January 24th Introduction to Oil Field Operations

Well Proposal and Well MonitoringJanuary 31st

Reservoir Modelling

The Review Cycle


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Objectives Well Planning, Monitoring

At the end of this session the participant should be able to:

Define the key geological contents of a well proposal Seismic data

Log data Hazards

Objectives, justification economics

Appreciate impact of geological reservoir / overburdenuncertainty on well costs via, well planning overburden, targets, placement

Drilling the well

well deliverability PIF, oil rims, fractures


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Operations Sessions - Purpose

Familiarity with well planning and implementation allows

Identification with role of geologist

Application of geology to field development

Geological Reservoir / Overburden uncertainties impact

well and FDP costs

Understanding of current well technology and limitations

Understanding the uncertainties provides opportunities to other

disciplines to improve working practises or apply technology

smartly



Link between FDP and well proposal



EP Lifecycle,

from exploration to decommissioning

MAXIMISE

NPV

Exploration

Appraisal

Primary

Devt

Decommission

Cumulativ

e$

Time

Further

DevtProduction

+

0

-



FDP costs

for150,000

bopd field



Extra costs from

debottlenecking



The Big Picture

What is the objective of the well?

What data do I need to obtain to meet the

objective?



Drilling



Making hole its a messy old game!



The Circulating System


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Well Drilled in Stages

Protect each drilled

section with casingprior to drilling next

section

Separate different rock

layers

Reservoir pressure &

fluid control


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Typical Exploration Well

Resistivity/Sonic/Density/Neutron/GR

DipmeterFormation Tester

Sidewall Samples

24

17 1/2

12 1/4

8 1/2

No logging

Resistivity/Sonic/GR (GR to surface)

Resistivity/Sonic/Density/Neutron/GR

DipmeterFormation Tester

Sidewall Samples

Velocity Survey

?

T i l W ll C t


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Typical Well Cost

0

Onshore

Offshore

1000

2000

Deptha

longholeinmeters

3000

4000

5000

6000

70000 5 10 15 20 25

Total Well Cost (Million US$)


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Well Proposal Contents


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What do you expect from a geologist?

Accurate Depth Prognosis

Realistic Well Target, Trajectory &

Tolerance Drilling Hazards

Losses

Pressures

Shallow Gas

Problem Shales etc. etc.

Stress State


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Well Proposal -Stratigraphic Column

- SchematicLithostratigraphy example

Al Waleed Syria


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Depth error on prognosis


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What do you expect from a geologist?

Top Reservoir / Maps / Cross-Sections

Reservoir Thickness & N / G

Structural Dip

OVERBURDEN Data (similar detail?)

Fluid Composition (Oil / Gas, CO2, H2S etc) Well Proposal (on TIME)

Logging & Completion Programme

Clear Tech. Reasons for Casing Points,Coring Points & TD

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