Geothermal Drilling Best Practices: The Geothermal translation of ...
5T. Geothermal Drilling Producing Well Integrity ... · Geothermal Drilling & Producing Well...
Transcript of 5T. Geothermal Drilling Producing Well Integrity ... · Geothermal Drilling & Producing Well...
Geothermal Drilling & Producing Well Integrity Challenges
Colin Stuart BEng FIMechE
Ken Seymour BSc PhD MBA CEng
22 September 2016
www.stuartwright.com.sg
Presentation outline
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1. Introduction to Stuart Wright
2. Geothermal Energy Trends
3. Geothermal Drilling & Producing Well Integrity Challenges
4. Solutions to Geothermal Drilling & Producing Well Integrity Challenges
5. Summary
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Introduction to Stuart WrightSafe and Reliable Wells
ConsultingIntelligent Risk
SolutionsTraining
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2. Geothermal Energy Trends
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Geothermal basics – where does the heat come from?
8 x 1012 W
32.3 x 1012 W
1.7 x 1012 W
• Clean and sustainable heat from the Earth.
• It yields warmth and power that we can use without polluting the environment.
• Geothermal heat originates from Earth's fiery consolidation of dust and gas over 4
billion years ago. At earth's core, temperatures may reach over 9000 °F.
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3 BCE 1904 Present Day
The oldest known pool fed by a
hot spring, built in the Qin
dynasty in the 3rd century BCE.
Prince Piero Ginori Conti tested the first geothermal power
generator on 4 July 1904, at the same Larderello dry steam
field where geothermal acid extraction began. It
successfully lit four light bulbs. In 1911, the world's first
commercial geothermal power plant was built there.
Geothermal power plants
operating in 25 countries
globally.
Geothermal has a long history
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Installed geothermal electric capacity by country
(2015)
0
500
1000
1500
2000
2500
3000
3500
4000U
nit
ed
Sta
tes
Ph
ilip
pin
es
Ind
on
esi
a
Me
xico
Ne
w Z
ea
lan
d
Ita
ly
Ice
lan
d
Ke
nya
Jap
an
Tu
rke
y
Ira
n
Co
sta
Ric
a
El S
alv
ad
or
Nic
ara
gu
a
Ru
ssia
Gu
ate
ma
la
Pa
pu
a-N
ew
Gu
ine
a
Po
rtu
ga
l
Ch
ina
Ge
rma
ny
Fra
nce
Eth
iop
ia
Au
stri
a
Au
stra
lia
Th
ail
an
d
Ele
ctri
c C
ap
aci
ty (
MW
)
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950
1000
1050
1100
1150
1200
1250
1300
1350
2007 2010 2013 2015
Ele
ctri
c C
ap
aci
ty (
MW
)
Indonesia Case Study
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Types of geothermal systems
HEATING & COOLING POWER
Ground-Source Heat Pumps Conventional GeothermalEnhanced Geothermal
Systems (EGS)
Simple Wells Complex Wells
- Hydraulic fracturing.
- Pump cold water from
surface through
fractures and heated
water back to surface
through a second well
to drive turbines.
- Summer: liquid moves heat from
building into ground.
- Winter: pre-warmed air & water
heats the building. Extract hot water hosted in naturally permeable
geological formations
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International Energy Agency (IEA) roadmap vision of
geothermal power production by region thru 2050
“By 2050, geothermal electricity generation could reach 1,400 TWh per year, i.e. around 3.5% of
global electricity production, avoiding almost 800 mega tonnes of CO2 emissions per year.”
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IEA predicted growth of geothermal power
capacities by technology
“By 2050, more than half of the projected increase comes from exploitation of ubiquitously
available hot rock resources, mainly via enhanced geothermal systems (EGS).”
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3. Geothermal Drilling & Producing Well Integrity
Challenges
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What is a well?
1. A well is a pressure vessel
2. It is a pressure vessel that is created in a pressure environment – drilling
3. A completed well consists of a tubular pressure vessel (tubing and casing), an adapter
(wellhead) and a series of valves (bop stack or xmas tree) – production
The challenge is maintaining wellbore integrity through both the drilling and production
phases.
BLOWOUT
PREVENTER (BOP)
DRILLING PHASE
WELLHEAD & XMAS
TREE
PRODUCTION PHASE
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P ≤ 5000 psi
T < 100 °C
Onshore Onshore
Offshore (Shallow Water)
Offshore (Deepwater)
Salt Dome
PP> 10k psi
BHT>300 F
Onshore
Offshore (Shallow Water)
Offshore (Deepwater)
Offshore (Ultra-Deepwater)
Salt Domes
PP>15 to 20K psi
BHT>400F
HP / HT / HPHT XHP / XHT / XHPHT / UHPHT
Rudimentary / Basic Well Design Approach
Low Importance to Material and Connection
Performances
Industry standard well
design software
(StressCheck, TDAS)
Engineered Well Design Approach
Proper Material Selection
Knowledge of suitable connection with reliable performances (ISO 13679 Cal I to IV)
Industry standard Well Design Software
(StressCheck, WellCat)
Advanced Well Design with Life Cycle
Well Integrity Approach
Industry Standard Well Design
Software with Thermal Simulation
(WellCat)
Proper Material Selection
Knowledge of Full Service Connection
Performances (ISO 13679)
Well complexity
Geothermal Wells
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Well integrity challenges in oil and gas wells
In a completed oil and gas well the ISO
standard recognises at least 26 possible leak
paths i.e. loss of integrity, some of which
could lead to an uncontrolled flow.
The oil and gas industry has developed
rigorous standards of best practice over the
last 100 years.
The geothermal industry has not developed
to this level of maturity, and generally follow
oil and gas well design principles.
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Oil & Gas vs. Geothermal wells complexity
20161859 1904
Well
Complexity
Index
Simple Wells Complex Wells Future Wells Prediction
Oil & Gas Geothermal Oil & Gas Geothermal Oil & Gas Geothermal
Max PP (psi) 5,000 5,000 20,000 10,000 20,000 15,000
Max BHT (⁰F) 200 200 400 500 500 1,500
Location Onshore Onshore On/Offshore Onshore On/Offshore On/Offshore
Oil & Gas
Geothermal
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Example loss of control events at geothermal sites
Iceland, 1999New Zealand, 1980
Australia, 2009
USA, 1998
Philippines, 2003
- Blowouts
- H2s release
- Seismicity events
- Landslides
- Pipe ruptures
- Turbine failures
Japan, 2010
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Future challenges for the geothermal industry
Future growth in deeper, hotter rocks (EGS) will need increasingly complex
wells which could become even more challenging than oil and gas wells due to
extreme high temperatures.
More complex wells leads to increased blowout risk and potentially lethal risks
with high pressure water or steam, which is compounded if H2s is involved.
The Geothermal industry need to evolve more complex well skills and Risk
Management to reduce risks of uncontrolled flow.
“We cannot afford the geothermal industry to become
another fracking issue”
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4. Solutions to Geothermal Drilling & Producing Well
Integrity Challenges
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Solutions must suit stakeholders on all sides…
Rigorous implementation of
standards
Appropriate risk ranking
Well drilling review
Proper barrier rules
implementation i.e. RTBC
Risk of losses reduction
Better targeting of premiums
Indication that risk is manageable
Assurance that risk is manageable
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1. To provide the Underwriter with a high level screening to
enable an estimated loss of control insurance premium to be
calculated.
2. The tool does not replace the Drilling Well Review in
determining the final level of risk for the well.
3. The tool is designed to identify risk elements existing
specifically for Geothermal projects.
Appropriate risk ranking
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P ≤ 5000 psi
T < 100 °C
Onshore Onshore
Offshore (Shallow Water)
Offshore (Deepwater)
Salt Dome
PP> 10k psi
BHT>300 F
Onshore
Offshore (Shallow Water)
Offshore (Deepwater)
Offshore (Ultra-Deepwater)
Salt Domes
PP>15 to 20K psi
BHT>400F
HP / HT / HPHT XHP / XHT / XHPHT / UHPHT
Rudimentary / Basic Well Design Approach
Low Importance to Material and Connection
Performances
Industry standard well
design software
(StressCheck, TDAS)
Engineered Well Design Approach
Proper Material Selection
Knowledge of suitable connection with reliable performances (ISO 13679 Cal I to IV)
Industry standard Well Design Software
(StressCheck, WellCat)
Advanced Well Design with Life Cycle
Well Integrity Approach
Industry Standard Well Design
Software with Thermal Simulation
(WellCat)
Proper Material Selection
Knowledge of Full Service Connection
Performances (ISO 13679)
Well complexity
Geothermal Wells
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# Geothermal Well Key Elements Risk Ranking
1Well is tapping a hot water source at a depth where temperatures exceed the boiling
point of water at ambient surface conditions
2Well is tapping a geothermal source rock where the water does not reach boiling point
at ambient surface conditions
3Well is tapping Hot Rock(s) or Enhance Geothermal System (EGS) source reservoir for
steam generation purposes
4 Geological Formations
5 Well Risk Management
6 Casing Design
7 New Technology
8 Multiple Targets/ Objectives
9 Change of Scope
10 Well Barrier Plan
11 Human Factors
Sample of high level risk ranking tool
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People ProcessWell Control
PreparednessEquipmentWell Type
SAFE
OPERATION
MAJOR
INCIDENT
Well Control Event Risk Rating
Well drilling review
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RTBC is a unique CLOUD BASED well barrier validation and monitoring solution that helps
to protect:
People
Assets
Environment
Proper barrier rules implementation i.e. RTBC
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RTBC software operating environment
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RTBC Daily Integrity Report sample
Wear bushing was found stuck across Blind
RAMs, but was subsequently retrieved on
20.12.2015.
Root cause investigation in progress.
Dies of spider slip fell while RIH scraper BHA.
Dies subsequently recovered via pipe RAM
bonnet after POOH BHA and closing Blind RAMs.
Root cause of dies slip fall currently unknown.
Kill line P-tested to 3000 psi for 15 mins
Valve HCR P-tested to 2500 psi for 15 mins on
04.12.2015.
Manifold P-tested to 2500 psi for 15 mins on
10.12.2015.
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Summary of Geothermal integrity issues
Rapid growth of Geothermal power generation
Geothermal wells becoming more complex
Application of Intelligent Risk Solutions to assess and manage risk
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