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Definitions of reserves and main difference between conventional and
non-conventional resources
IEA Energy Training Week
Paris, April 4, 2013
Master of Advanced Studies in International Oil and Gas Leadership
Giacomo Luciani
Ja
nu
ary
20
13
3 2003
Exploration Appraisal Development / Production
Estimated ultimate recovery, MMbbl
Range of
uncertainty
High estimate
Best estimate
Low estimate
Cumulated production
Time 0
Decrease with time of uncertainty in reserve estimation
Reserves
• Reserves are those quantities of petroleum which are anticipated to be commercially recovered from known accumulations from a given date forward.
• All reserve estimates involve some degree of uncertainty.
• Classification according to the relative degree of uncertainty: Proved reserves
Unproved reserves
• Probable reserves
• Possible reserves
Source: Society of Petroleum Engineers (SPE) Inc., 2000
Proved reserves (P90)
• Quantities of petroleum which, by analysis of geological and engineering data, can be estimated with reasonable certainty (90% probability) to be commercially recoverable…
• Recoverable: From a given date forward,
From known reservoirs, and
Under current economic conditions, operating methods, and government regulations.
• Proved reserves can be categorized as: Developed, or
Undeveloped.
Source: Society of Petroleum Engineers (SPE) Inc., 2000
Unproved reserves
• Based on geologic and/or engineering data similar to that used in estimates of proved reserves;
• But technical, contractual, economic, or regulatory uncertainties preclude such reserves being classified as proved.
• Unproved reserves may be further classified as:
Probable reserves, and
Possible reserves.
Source: Society of Petroleum Engineers (SPE) Inc., 2000
Probable reserves (P50)
• Unproved reserves which analysis of geological and engineering data suggests are more likely than not to be recoverable.
• There should be at least a 50% probability that:
the quantities actually recovered will be ≥
estimated proved reserves + probable
reserves.
Possible reserves (P10)
• Unproved reserves which analysis of geological and engineering data suggests are less likely to be recoverable than probable reserves.
• There should be at least a 10% probability that:
the quantities actually recovered will be ≥
estimated proved + probable + possible
reserves.
Source: Society of Petroleum Engineers (SPE) Inc., 2000
Speculative or Undiscovered Resources
• Estimates of petroleum that might exist in a basin based on extrapolation of data on discovered resources, exploration intensity, number of wells drilled etc.
• Based on geological knowledge, but no two basins are the same…
From resource in place to proved reserves
Reserves “growth”
• Reserves are always estimated, they cannot be exactly measured
• The estimate of the reserves in a field changes with time, because our knowledge of the field improves while producing the oil from it
• Normally, the estimate increases, and reserves are said to “grow”: it is not the reserves that grow, it is just our knowledge and consequently our estimate that changes
• But sometimes our estimate is reduced
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Given the current proven reserves base, a 1% increase in the
average recovery rate would add 1 year extra oil production
Source: IEA, World Energy Outlook 2005
Unconventional vs. Conventional
Upside Downside
• Expensive drilling and
completion
• Oil upgrading is capital
intensive
• Low energy return on
investment
• Large greenhouse gas
emissions
• High oil recovery requires large
amounts of water
• High gas recovery requires
high well density
• Potential for groundwater
contamination
• Low exploration risk
• Long-life reserves
• Stable, predictable
production
• Assembly-line development
• Long project life provides: opportunity to improve
recovery
opportunity to improve
efficiency
security of supply
• Gas decline rates decrease
with time
Shale oil and Tight oil
In contrast to shale oil, which remained trapped in the original shale source
rock, the producing area, like the Bakken, contains migrated oil trapped in
siltstone and sandstone between layers of shale. The Eagle Ford’s oil is
trapped in carbonate rocks overlying shale from which it migrated
Tight shale oil: conventional oil extracted by unconventional means
because of lack of porosity and permeability
Horizontal drilling & hydraulic fracturing: « fracking »
The top three producing tight oil plays: Bakken, Eagle Ford, and Niobrara
account for 90% of total US tight oil output, currently about 620,000 b/d
extensive areas, high first-year well decline rates varying from 65% to
90%, and low recovery efficiencies averaged over the entire play: 1-2%
for tight oil. For 'sweet-spots' in the play such as Elm Coulee field, oil
recoveries can reach 5-6%
Potential in China, Australia, Middle East, Central Asia, Russia, Europe,
Argentina and Uruguay
Source: « evaluating production potential of mature US oil shale plays », Rafael Sandrea, IPC Petroleum
Consultants Inc., Dec 2012
Tight Oil Production for selected plays in the US
Source: Oil & Gas Journal, Dec 3, 2012
Heavy, Extra-Heavy Oil and Oil Sands
Essential component of oil resources
OIP estimated between 4,000 and 5,000 Gb
Reserves up to 600 Gb
80% of all heavy oils are in fact extra-heavy
Oil sands are included in this category
Accumulations in all parts of the world: Russia, USA, Middle East, Africa, Cuba,
Mexico, China, Brazil, Madagascar, Europe, Indonesia
The largest are located in Venezuela (The Orinoco Belt) and Canada (Province of
Alberta
Heavy oil is oil that has become extremely viscous as result of biodegradation
Bacteria active at low temperatures associated with shallow deposits consume the
lighter hydrocarbons, leaving behind the more complex compounds such as resins &
asphaltenes
Heavy Oil Classification
Source: F. Cupcic (TOTAL) - ASPO 2003
20,0
d°API: between 7° and 20°
Viscosity: between 100 cPo and 10 000
cPo = mobile at reservoir conditions –
can be recovered using Cold production methods
d°API: 7° << 12°
viscosity: 10 000
cPo<< 8 000 000
cPo) = non mobile.
Mining up to 100 m.
Deeper, Thermal
recovery methods
Canada
Venezuela
Light > 31
°API = 141.5/ density - 131.5
23
Orinoco Belt versus Alberta: same order of magnitude for the
reserves
IOIP: 1400 Gb (source: PDVSA)
Reserves: 180 Gb* (source: PDVSA)
IOIP: 1800 Gb (Source: AEUB)
Reserves: 160 Gb (Proven)
* Proven reserves with a mixed cold / thermal technology
Source: PDVSA, AEUB (Alberta Energy and Utilities Board), BeicipFranlab 2012
24
Oil Sands: Production Techniques
Source: Total
SA
GD
pro
du
cti
on
Surface Mining
Depth < 100m
20% of deposit
50% of today production
Lower energy intensity
Lower relative GHG
emissions
In situ
Depth > 100m
80% of deposit
50% of today production
Higher energy intensity
Higher relative GHG
emissions
Higher break even point
Surface Mining (1)
5 M$ each – 400 t
Technical cost
40%: mining
37%: separation bitumen from sand
23%: upgrading
In Situ
27
In-Situ Exploitation
By Steam water
Recovery rate
20-25% Cycling injection: 1 well alternatively for injection and
production
40-60% Steam Assisted Gravity Drainange (SAGD)
Scale: 50 000 b/d
Usually no upgrading but diluted bitumen
Huge quantity of water required
1 b of water / 1 b of bitumen
to produce the steam water (energy source: natural gas)
Other techniques of injection (R&D)
Solvant injection
Combustion in-situ
28
Oil Sands production Technologies: IN SITU (1) (thermal)
Cyclic Steam Stimulation (CSS) since 1985
CSS: better adapted to heterogeneous reservoirs and less viscous fluids of the
Cold Lake Area
Source: Total
29
Steam is injected into the oil producing reservoir
As the steam permeates the sand, the oil is heated and becomes less viscous
The oil flows more freely through the wellbore's slotted liner and is pumped to the surface
Better adapted to homogeneous reservoirs and highly viscous fluids of the north & south
Athabasca area
Source: Total
Oil Sands production Technologies: IN SITU (2) (thermal)
Steam Assisted Gravity Drainage (SAGD) since 2001
31
Naphta (for
transportation
Mining
Upgrading
Extraction
in-situ
Bitumen
Dilution Diluted Bitumen:
Dilbit (75+ Bit. + 25%
Naphta) / Synbit (50% Bit. + 50% SCO)
Synthetic Crude
Oil (SCO)
Refinery SCO or Naphta
(for commercialization)
50%
50%
Processes from Production to Refining
The bitumen extracted from the oil sands is very heavy and viscous. Once extracted, lighter
hydrocarbons (Naphta) can be added to the bitumen in order to be further processed or upgraded into a
form of synthetic crude oil (SCO) that is less viscous. After that, it can be sold to a traditional oil
refinery, though some bitumen is also sold in raw form for the production of heavy products like tar and
asphalt
Currently 5 operational upgraders in Alberta, 2 of which commenced commercial operation in 2009 –
Horizon & Long Lake
Sand
Water
Bitumen
Tailing Pond
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Production costs