Petroleum Geology
Prepared by:
Dr. Emmanuel V. Tamesis
Oil and Gas Exploration
A. Introduction
& Petroleum exploration is very expensive. It will cost
around US$ 4 to 10 million onshore to as much as US$
30 million offshore to test if oil is present in a prospect.
These costs include pre-drilling expenses for geology
and geophysical activities
& A good understanding of the sedimentary basin is
essential for a drilling decision, and all available
information must be used to evaluate a drilling prospect
& Drilling an exploratory (wildcat) well is the testing of a
hypothesis developed out of gathering, classifying and
evaluating related scientific data
& If successful, the efforts and fruit of labor is very
rewarding -- most of the world’s top corporations are oil
companies
Oil and Gas Exploration
B. Where Do We Start?
Since petroleum formation, generation and entrapment
involves the sedimentary sequence, the petroleum
geologist has to identify where the sediments, the
source of organic matter and reservoir rocks have been
deposited -- the sedimentary basin
1. What is a sedimentary basin?
& A depression formed by tectonic processes, flanked by
topographically high areas that shed thin detritus into
this depression
& It is a settling pond, underlain by basement rocks such
as igneous rocks, metamorphic rocks or even
sedimentary rocks which are not capable of generating
oil or gas (sometimes called economic basement)
Oil and Gas Exploration
B. Where Do We Start?
Sedimentary
Basins
of the Philippines
Oil and Gas Exploration
Central Luzon Basin
Oil and Gas Exploration
What is a sedimentary basin?
& The basin, besides containing detritus and organic
matter, also contains water entrapped with the clastic
sediments during the basin-filling stage
& The sedimentary fill may consist of sandstones, silts,
conglomerates, coal and carbonate deposits such as
limestone and dolomite
2. Objectives of a Sedimentary Basin Analysis
a. Depositional history
i. Environment of deposition
ii. Facies analysis - a study of changing deposits
within a stratigraphic unit, or, bound by
contemporaneous time lines
Oil and Gas Exploration
2. Objectives of a Sedimentary Basin Analysis
a. Depositional History (cont’n)
iii. Sedimentary history
iv. Stratigraphic hiatus - breaks in the rock record
represented by unconformities, diatoms, etc.
And from these, determine which stratigraphic units are
the potential source rocks, reservoir and seal
b. Structural Evolution
i. Basin settings
ii. Basin-forming processes
iii. Syn-depositional deformational processes
iv. Post-depositional deformational processes
And from these, identify structural style and play types
Oil and Gas Exploration
2. Objectives of a Sedimentary Basin Analysis (cont’n)
c. Geological Disciplines Employed in Petroleum
Exploration
• Sedimentology
• Stratigraphy
• Structural Geology
• Geochemistry
• Petrography
• Geophysics
Exploration Strategy
Economic
Frontier
Geologic Basin Basin Appraisal Prospect
Exploration
Considerations Delineation Evaluation of Plays Generation
Strategy
Political
Appraisal of Plays
Acquisition
of Seismic
Detailed
Satellite Imagery
Analysis to
Appraisal Localize Structural
of Plays Anomalies
On-Site
Construction Reflectance
of Geologic Map Spectra
Subsurface
Sedimentologic Stratigraphic
Outcrop Analysis Projections
Geological
Field Party
Conventional
Stratigraphic
Mapping
Prospect Generation
Semi-Regional
Seismic with
In-Fill
Determination of
Size of Structures
and Geologic
Growth History
Prospect Specific Prospect Operational
Generation Evaluation Preparation
Determination of
Petrophysical
Synthesis and Pore Water
Prognosis Salinities Porosity and
Permeability
General Evaluation Sedimentologic
of Prospect Location Projections
with in Play Framework Environmental
Setting as Determined
by Sedimentologic
Synthesis Sedimentologic
Projections
Environmental
Flow of Upstream Petroleum Activities
BASIN EVALUATION
EXPLORATION
Í
PROSPECT IDENTIFICATION
Í
EXPLORATION WELL DRILLING
Í
Petroleum E & P
FIELD DELINEATION AND DEVELOPMENT PLANNING
Í
DEVELOPMENT WELL DRILLING AND FIELD PRODUCTION
Í
REVISIONS TO DEVELOPMENT STRATEGY
Í
WORKOVERS AND INFILL DRILLING
PRODUCTION
Í
ENHANCED RECOVERY
Í
FIELD DECLINE
Simplified Exploration Cycle
2 1 8 9 10
Literature
Exploration Extended
Procurement research or
drilling Discovery Well, Prod.
of block Farm-in
NX6 Test
Proposal
3 7
if packaged by farmor
9A 11
6
Technical Step-
Geological Basin Prospect
Problems, out
activities1 Evaluation44 Generation5
Dry, Show well
2-D
Pre-seismic
Seismic Appraisal 3-D
geophysical 5
survey 33 ABANDON AREA wells seismic
surveys 2
7
13
4 5 A
12
DECLARATION
OF
COMMERCIAL DISCOVERY
14
4 - BASIN EVALUATION 5 - number of exploration or
1 - GEOLOGIC ACTIVITIES 2 - PRE-SEISMIC GEOPHYSICAL 3 - 2-D SEISMIC SURVEY Seismic interpretation geologic plays
Field mapping & sampling Gravity & Magnetics Reconnaissance Integration of geological and = number of valid tests
Laboratory analyses Detailed geophysical data before abandonment
Photogeologic interpretation Data synthesis
Structural & stratigraphic studies 6 - number of exploration
Post-mortem analyses of well plays
results
Petroleum Exploration
Three main stages involved in searching for petroleum deposits:
Surface mapping of a sedimentary basin, which includes rock sampling and
laboratory analysis, and the study of all Geological and structural data.
Geophysical methods such as magnetic, gravity and seismic surveys are
employed to gather more information about the subsurface.
Drilling of an exploratory of ‘wildcat’ well over an identified prospect is the
final test to confirm the presence of any hydrocarbons.
Oil and Gas Exploration
2. Objectives of a Sedimentary Basin Analysis
d. Four Levels of Petroleum Investigation
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance – field geology, gravity, magnetic and seismic
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance – field geology, gravity, magnetic and seismic
a. Field Geology
Road Mapping Coastal Mapping Aerial
Reconnaissance
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance – field geology, gravity, magnetic and
seismic
a. Field Geology - rock identification and sampling
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
b. Gravity and Magnetic
Ship-borne
Survey
Gravimeter:
Measures
minute
differences in
Magnetometer: the pull of
measures variations in the gravity at the
earth’s magnetic field earth’s surface
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
b. Gravity
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
b. Magnetic
Air-borne Survey Aircraft
Land Gravity Meter
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
c. Seismic
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
c. Offshore Seismic
An energy pulse (from an air explosion or an electrical discharge) is sent
to the subsurface layers and reflected waves are picked up by
hydrophones contained in a streamer being towed by the survey vessel.
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
c. Offshore Seismic
Streamer Cable
Air-Guns
Seismic Boat
3D Offshore Seismic Survey
In 3D surveys, a multi-streamer array is
towed by the seismic ship, acquiring
overlapping swaths of data over the
entire survey area, which are then
merged to form a 3D survey block.
Offshore Data Recording
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
c. Onshore Seismic
Shot holes are drilled to penetrate the weathering zone.
An explosive charge, usually dynamite, is loaded into the shot holes and
detonated, sending sound waves into the sub-strata which are variably reflected
back to the surface.
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
c. Onshore Seismic
In some instances,
an array of huge
truck-mounted
vibrators is used as
the energy source,
instead of an
explosive charge, for
transmitting sound
waves to the sub-
surface.
Wave Propagation
(through homogenous medium)
Energy Source
Wave Propagation
(through layered medium)
Energy Source
Seismic Interpretation Workstation
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
1. Reconnaissance (cont’n)
c. Onshore Seismic
Sound waves reflected from the sub-surface are
picked up by an array of geophones which are laid
out on the ground along a seismic line and
connected to recording instruments through a
seismic cable.
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
2. Detailed Seismic
2D vs. 3D Seismic Data
Three-Dimensional (3D)
Seismic
Two-Dimensional (2D)
Seismic Z
X
Y Y
2D Seismic Interpretation
Pinnacle Reefs
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
2. Detailed Seismic
Un-interpreted Section
Interpreted Section
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
2. Detailed Seismic
W E
MA-1 MA-2
3000
3D Seismic Interpretation
Seismic Interpretation
Composite 2D / 3D Display
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
2. Detailed Seismic
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
2. Detailed Seismic
3D Display
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
3. Wildcat Drilling
Oil and Gas Exploration
C. Five Stages in Petroleum
Exploration
3. Wildcat Drilling
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
4. Appraisal Drilling in Case of Discovery
Oil and Gas Exploration
C. Five Stages in Petroleum Exploration
5. Production
Oil and Gas Exploration
D. Drilling Rigs
1. Onshore
Oil and Gas Exploration
D. Drilling Rigs
2. Offshore
Oil and Gas Exploration
D. Drilling Rigs
2. Offshore Drilling and Production Facilities
Oil and Gas Exploration
E. Production Facilities
Nido-Matinloc
Oil and Gas Exploration
E. Production Facilities
Galoc
Oil and Gas Exploration
E. Production Facilities
Alcorn
Oil and Gas Exploration
E. Production Facilities
2. Malampaya
Oil and Gas Exploration
E. Production Facilities
2. Malampaya: Subsea Manifold
Malampaya Deep-Water Gas to Power
Project
• Initial Development consists of five
production wells drilled from a central
location into the main culmination of
the Malampaya reservoir
• Subsea wells and a subsea manifold
were installed at approximately 820
meters deep and connected to the
production platform via two 30-km
flowlines. Umbilical cables remotely
control the wells and manifold
• Each well is designed to produce 180
million cu. ft. of gas per day
• Four additional production wells are
planned for 2009
Malampaya Offshore Facilities
• The Offshore Platform can
handle 500 million cu. ft. of
gas and 26,000 barrels of
condensate per day
• The concrete gravity
structure has a storage
capacity of 300,000 barrels;
stored condensate is
offloaded by shuttle tankers 113 m
for shipment to markets
• The export pipeline to
Luzon has a capacity of 650
million cu. ft. of gas per day
Malampaya Subsurface Facilities
MA-9
MA-5
Subsea Manifold
MA-6
MA-7
MA-8
Wellhead
Oil and Gas Exploration
E. Production Facilities
2. Malampaya: Topside, Offshore Platform
Oil and Gas Exploration
E. Production Facilities
2. Malampaya: Onshore Power Plant
Malampaya Downstream Component
SAN LORENZO POWER PLANT /
First Gas Corp, 500 MW / Oct 2002
STA. RITA POWER PLANT /
First Gas Corp. 1,000 MW / Jan 2002
ONSHORE GAS PLANT/
SC 38 Consortium/Oct 2001
ILIJAN POWER PLANT /
KEILCO 1200 MW / June 2002
Petroleum Products
A Barrel of Crude Oil Provides:
Gasoline - 19.5 gallons
One Barrel
= 42 gallons Fuel Oil - 9.2 gallons
Jet Fuel - 4.1 gallons
Asphalt - 2.3 gallons
Kerosene - 0.2 gallons
Lubricants - 0.5 gallons
Petrochemicals,
other products - 6.2 gallons
American Petroleum Institute, 1999
&
Importance of Petroleum
• Energy Source
– over 2/3 of the world’s energy sources comes from
petroleum
– in the Philippines, 46% of our energy (power, fuel and
transport) requirements comes from oil
• The Philippines consumes around 350,000 BOPD, of
which nearly 99% is imported
Petroleum Use in the Philippines
Form / Use %
• Power 25.7
• Diesel 35.4
• Premium Gasoline 14.4
• Regular Gasoline 4.6
• LPG 9.9
• Jet Fuel 5.4
• Kerosene 3.9
• Others (asphalt, avgas, etc.) 0.7
Philippine Energy Plan 2004 - 2013
Primary Energy Mix 2004
Coal
Oil 2.6% Hydro
2.1% 5.3%
imported oil
Gas 36.6%
6.7%
Geothermal
7.9%
Other RE imported coal
30.9% 7.9%
Indigenous Energy - 152 MMBFOE Imported Energy - 122 MMBFOE
Self-sufficiency – 55.5%
TOTAL : 274 MMBFOE
