PS
Geochemical Exploration in Northern South America: Recent Successes from Venezuela, Colombia, and Peru*
Dietmar Schumacher1
Search and Discovery Article #30287 (2013)**
Posted October 29, 2013
*Adapted from a poster presentation given at AAPG International Conference and Exhibition, Cartagena, Colombia, September 8-11, 2013
**AAPG©2013 Serial rights given by author. For all other rights contact author directly.
1
E&P Field Services, USA, France, and Malaysia ([email protected])
Abstract
Detailed geochemical and research studies document that hydrocarbon microseepage from petroleum accumulations is common, is
predominantly vertical (with obvious exceptions in some geologic settings), and is dynamic (responds quickly to changes in reservoir
conditions). Since microseepage is nearly vertical, the extent of an anomaly at the surface can approximate the productive limits of the
reservoir at depth. Furthermore, the detailed pattern of seepage can reflect reservoir heterogeneity, discriminate between charged and
uncharged compartments, and identify areas of bypassed pay.
Results of recent microbial and soil gas surveys in Venezuela, Colombia, and Peru establish the value of hydrocarbon microseepage data for
high-grading prospects and aiding field development projects. These surveys were conducted in the Eastern Venezuela basin, the MaracaiboCatatumba basin in western Venezuela, the Guajira and Cesar Rancheria basins in northern Colombia, the Middle Magdalena Valley basin in
central Colombia, and the Lancones basin in Peru. Results from the underexplored Lancones basin identified structures that warrant additional
study due to strong hydrocarbon indications. The Guajira survey documented previously unrecognized oil potential in a basin known only for
its biogenic dry gas. Results from eastern Venezuela and Cesar Rancheria successfully discriminated prospects on basis of probably
hydrocarbon charge. Surveys over two old oil fields in western Venezuela and in the Middle Magdalena Valley identified bypassed pay and
several new drilling opportunities.
High-resolution microseepage surveys offer a flexible, low-risk and low-cost environmentally friendly technology that not only complements
traditional geologic and seismic data, but add value to such data. Properly integrated with other exploration data, their use has led to discovery
of new reserves and drilling fewer dry or marginal wells.
Geochemical Exploration in Northern South America:
Recent Successes From Venezuela, Colombia, and Peru
Dietmar (Deet) Schumacher, E&P Field Services -- USA, France, and Malaysia
ABSTRACT
Detailed geochemical and research studies document that
hydrocarbon microseepage from petroleum accumulations
is common, is predominantly vertical with obvious exceptions in some geologic settings), and is dynamic (responds
quickly to changes in reservoir conditions). Since
microseepage is nearly vertical, the extent of an anomaly at
the surface can approximate the productive limits of the
reservoir at depth. Furthermore, the detailed pattern of
seepage can reflect reservoir heterogeneity, discriminate
between charged and uncharged compartments, and identify areas of bypassed pay.
Results of recent microbial and soil gas surveys in Venezuela, Colombia, and Peru establish the value of hydrocarbon microseepage data for high-grading prospects and aiding
field development projects. These surveys were conducted in the Eastern Venezuela basin, the MaracaiboCatatumba basin in western Venezuela, and Guajira and
Cesar Rancheria basins in northern Colombia, the Middle Magdalena Valley basin in central Colombia, and
the Lancones basin in Peru. Results from the under explored Lancones basin identified structures that warrant additional study due to strong hydrocarbon indications. The Guajira survey documented previously
unrecognized oil potential in a basin known only for its biogenic dry gas. Results from eastern Venezuela
and Cesar Rancheria successfully discriminated prospects on basis of probably hydrocarbon charge. Surveys
over two old oil fields in western Venezuela and in the Middle Magdalena Valley identified bypassed pay
and several new drilling opportunities.
High-resolution microseepage surveys offer a flexible, low-risk and low-cost environmentally friendly technology that not only complements traditional geologic and seismic data, but add value to such data. Properly integrated with other exploration data, their use has led to discovery of new reserves and drilling
fewer dry or marginal wells.
BASICS OF HYDROCARBON MICROSEEPAGE
Most oil and gas accumulations have a surface geochemical expression, unless they are greatly
underpressured or contain heavy oil (API Gravity < 15)
Petroleum accumulations are dynamic and their seals imperfect
Hydrocarbons can move vertically through thousands of meters of strata without observable faults
or fractures in relatively short time (weeks to months)
Microseepage is dominated by hydrocarbon gases (C1 - C5) and aromatic hydrocarbons
Microseepage is predominantly vertical except in structurally complex areas with many faults or
fracture leak points
Prospects with an associated microseepage anomaly are 4 to 6 times more likely to result in a commercial discovery than prospects lacking such an anomaly.
MICROSEEPAGE DETECTION METHODS
Due to the varied surface expressions of hydrocarbon microseepage, a number of different methods are
available for detecting and mapping hydrocarbon microseepage. Some of these methods are surface geochemical methods, some are microbiological, and some are non-seismic geophysical methods.
MICROSEEPAGE MODEL
Halo
Apical
Halo
Anomaly
GEOCHEMICAL
Anomalous Surface Concentrations
Carbonate Precipitation
Oxidizing Zones
Pyrite Precipitation
High Polarization Anomaly
also sulphur, pyrrhotite
greigite, uranium, etc.
Bacterial Degradation
of Hydrocarbons
Light Hydrocarbons Seep
Upward from Trap Creating
a Reducing Zone
GEOPHYSICAL
High Resistivity Anomaly
Reducing Zones
Magnetic Anomaly
Low Resistivity Anomaly
Seismic Velocity Anomaly
Gas
Oil
Water
Remote sensing, satellite imagery analysis.
Detects hydrocarbon-induced alteration of soils and
sediments
Aeromagnetics, micromagnetics.
Detects seep-induced magnetic anomalies in shallow
subsurface
Soil gas, acid extracted soil gas, fluorescence.
Measures concentration and composition of hydrocarbon gases and aromatic hydrocarbons in soils
Microbiological.
Measures concentration and distribution of hydrocarbon-utilizing bacteria
Biogeochemical, geobotanical.
Measures trace elements and vegetation stress due
to hydrocarbon leakage
Survey Design Considerations
Sampling Strategy - Survey Design
Survey Objectives
Target Size, Shape
Geologic Setting
Topography, Vegetation
Logistical Considerations
Ability to Sample Along, Between Seismic Lines
Geologic Analogs for Calibration
Permitting; Environmental Issues
Prior Experience
Data Integration
PANEL 1
MOST & SSG Anomalies
N 1790000m
H
-30C1
A -29C1
-28C1
C1 -11
-27WB
C1
-7A
-5A
-32
WB26
WB
-25C1C1
C1
-23 -24
-33
C1 C1
C1
-22
C1
-34
C1
-21
1
C1-3)
G-Ballena-1
(C2
-35
-20
C1
C1
G-2
-19
-36
G-3
C1
C1
G-4
-18
-37
C1 G-11
C1
G-5
-17
G-6
C1 G-10
-38
C1
G-7
-16
C1
-39
G-8
C1
-15
C1
-14
G-9
-40
C1
C1
N 1785000m
N 1780000m
C1
-12
C1
C1
N 1775000m
-13
C1
C1
-45
C1
-46
C1
-47
C1
Rancheria-2
C1
-5
C1
C1
N 1765000m
C1
-3
-2
-1
C1
1K-4
-1 -5
2K1K
-7
1K-6 1K 1K-8
-2
2K
-3
2K
B-1
L-1
-4
2K
B-2
-9
1K 1K-10
-5
2K
-6
2K
-7
2K
L-2
L-3
B-4
L-4
B-6
-11
1K 1K-12
-13
1K
-14
1K
B-5
X
X
X 2K 1K
3K
E
N 1750000m
-15
1K 1K-161K-17 -18
1K 1K-19 0A
K-3 -209A A
1KK-2 1-1
-21
A 8A -227A
AL1KK-2
1-2 1K
AK-2 -236A
ALA 1-6
1KK-2 -245A
ALA
1KK-2
1-3
AL1-4
AL A
-25
4A
1K
K-2
3A
-26
AL1-5
1K
K-2
2A
-27
Almirante
1K
K-2
L-5
Aruchara-2
N 1740000m
0A
S-2
9A
S-1 8A
3A
S-1
L-2
7A
4A
S-1
L-2
6A
S-1
5A
5A
L-2
S-1
6A
4A
L-2
S-13A
7A
S-1
L-2
2A
8A
S-1
L-2 9A
A
L-2 0A
S -11
A
L-3
SA-10
1A
L-3 2A
S-9
3A
L-3 L-3 4A 5A
A
6A
L-3 L-3
S-8
9A 0A 1A 2A
L-3 L-37A 8A
-3A-2AA-1A
4A 5A
L-3 L-3 L-4 L-4 L-4 L-43A
SESES-7
L-4 L-4 L-46A 7A
SE
A8A A
A
L-4A-1
9A
L-4A-2
S-6
L-4A-3A0A A
1A
A
L-5A-4
L-5 A2A
S-5
A-5
L-5A-6A3A
A
L-5A-7A4A
S-4
L-5 A5A
A
A-8
L-5 A6A
S-3
A-9
L-5 0A
7A
A
A-1
8A2A
L-5A-11A
S-2
9A 0A
1A 5A
3A4A
4A 8A
5A 9A
7A
L-5A-1
2A 6A
A
6A 0A
7A 1A
8A 2A
3A
9A 3A 4A 5A 6A
L-5 L-6
L-6A-1
A-1A-1
L-6A-1
L-6A-1
L-6A-1
7A 8A 9A0A
L-6A-2
L-6A-2
L-6A-2
S-1
L-6A-1
L-6A-2 A-2 A-2A-2
A-2 A-2 A-2A-3
A
-6A
SN
-5A
SN
-4A
SN
-3A
SN
-2A
SN
-1A
SN
B
N 1735000m
C
N 1730000m
I
K
4A
L-1
5A
L-1
6A
L-1
7A
L-1
8A
L-1
9A
L-1
0A
L-2
1A
L-2
2A
L-2
N 1745000m
1A
U-3
0A
U-3 9A
U-2
8A
U-2 7A
U-2 A
U-265A
U-2
4A
U-2 3A
U-2 A
U-22
1A
U-2
0A
AF-2
A A
U-2 9A
AF-3
F-5F-4
U-1
A
8A
A
F-7
U-17A
F-8
A
U-1
0A
1AF-9
7A6A 5A 3A2AF-1
3A2A1A0A 9A F-1
F-2
AB 6A
F-2
F-2
F-2F-1 F-1 F-1 F-1F-1F-1
AB5A
U-2 U-1
5A
U-1U-1 A
F-2
U-14
3A
U-1 2A
6L-1A
U-1 1A
6L-2A
U-1
21AB
-1A
0A
M-3A
AB
WM
-2A
U-1 A-3A
6L
20
AB
-51
M199A
WMWM
1K
U-9
6L-4A
-52
MF-3
A
AB
1K
181A
-53
-5A
U-8Maicao-1
MF-4AB
A
1K
6L
17
-54
U-7
M-AB
1K
3A
-55
A
6L-6A
16
1K 1K-56
F-4
U-6 A
M15AB 4 6A
A
-57
M1K 1K-58 -59
AB F-4M6L-7A
5A58
U-5
F-4 F-4A
1K
A
M-14
-60
57
6L-8A
1K 1K-61 -62
U-4A
AB M-A
1K
-63
56
M-13
U-3 A
6L-9A
1K
-64
AB M- A
A
1K
-65
U-2A
M-12 M-55
1K
-66
6L-10
A
1K 1K-67 -68
U-1
1K
-69
6L-11
A
1K 1K-70
7A 6A
6L-12
Z-1Z-1Z-15A4A 3A 2A
A
Z-1Z-1Z-1 1A 0A A
A
6L-13
Z-1Z-1Z-9 A A A
Z-8Z-7Z-6 A A
M-A54
53
M-A
Z-5Z-4
A
Z-3Z-2A A
M-A52
Z-1
9AB
A51
M50
MM-A
AB
M-A49 M-10
M-A48
11AB
MM-47
46A
M-A
M-A45
M-A44
43
M-A
42
M- A
M-41
40A
M39A
M38A
M- A
M-A37
A
M-36
M-35
34A
M- A
M-33
32A
M- A
31
MA
saure-1
M-30
29A
MA
28
M27A
M-A
26
M-A
M-A25 1AB
24
M-A
M23
M-A
2AB
M-A22
MB
21
Guaitapa-1
M20A
M-3A B
M-A
4A
MB
M-19
18A
M-5A
MA
B
A
17
MM-6A
A 16
A MA 14
B
M-15
M-A13MA 12
M-7AB
A MM-11
M-8A
M-10
9A
A
3A
-14
2A 1A 1-1
0A
PF
1-1
1-1
PF PF1-1PFPF
5A 1-8AA
1-1 PF1-9
PF PF
A
1-7
Epehin-1
PF A
1-6
PF A
1A
-28
0A 9A
1K
K-2
-29
1-5
-30
1K
PF A
K-2 1K
8A 7A
K-1
-31
1-4
1K
-32 -33
K-1 K-1
6A
PF A
1K 1K
5A
K-1
-34
1-3
K-1
1K K-14A
-35 3A
PF A
1K K-1-36
1K K-12A
-37
1-2
-38
1K K-11A
PF A
1K K-10A
A-40
1-1A
1K-39
K-9
PF
1K K-8 -41 A
1K K-7 -42 A
1K K-61K-43 A
-44 A -45 A -46 A
K-5
A
1K K-41K
K-31K K-21K-47
K-11K-481K-49
-50
1K
-8
2K -9
2K -10A
2K A
-11
2K -12A A
-28
2K -13 A
2K
2K -14
-29
2K
A
Tinka-12K-15 A 2K -30
3
2K
-16
-24
2K -17A-18 -19
-31 -212K-222K-2 2K
-25 -26 -27
2K2K-20
2K 2K 2K
2K
2K 2K 2K
-32
2K
-33
2K
-34
2K
Aruchara-1
L-6
A
B-7
A
L-7
A
B-8
A
L-8
A
B-9
A
L-9
0A
B-1
0A
L-1
1A
B-1
1A
L-1 2A
B-1
2A
L-1 3A
B-1
3A
L-1 4A
B-1
N 1755000m
-50
F
B-3
N 1760000m
-48
-49
C1
-4
C1
C1
-2
1K
-3
1K
-41
-43
-44
C1
G
-1
1K
GUAJIRA BASIN-BAJA GUAJIRA AREA NORTHERN COLOMBIA
METHANE CARBON ISOTOPES
sample S-1A
-57.1
sample A-26A
-50.9
sample A-27A
-45
sample A-29A
-26.8
sample A-30A
-28.1
-50.6
sample M-5AB
-42
C1
-11
-10
C1
-9
C1
-5A
WA
-4A
WA C1-8
-3A
-2A
WA
-7
WA
C1
-1A
WA -6
Riohacha-1
C1
N 1770000m
-31
J
D
AAA
-12
-11
-10
-9A
-8A
-7A
-6A
-5A
-3A
-4A
-2A
-1A
-6A-5A-4A
SO
SO
SO
SO
SO
SO
SO
SO
SO
SO
SO
SESESE SO
MM-8A
M-7A
M-6A
4A 5A
M- MM-3A
M-2A
M-1A
Sorpresa-1
Manantiales-1
2A 1A4A
A-3
A-3 A-3
3A
A-3 6A
A-3
8A
A
A-3
E-1
N 1725000m
Sistema de fallas de OCA
N 1720000m
E 1120000m
E 1125000m
E 1130000m
E 1135000m
E 1140000m
E 1145000m
E 1150000m
E 1155000m
E 1160000m
E 1165000m
0 Km
E 1170000m
2 Km
4 Km
E 1175000m
6 Km
E 1180000m
E 1185000m
E 1190000m
E 1195000m
E 1200000m
E 1205000m
E 1210000m
E 1215000m
E 1220000m
8 Km
Geologic Setting
The Guajira basin occupies the southern part of the Guajira Peninsula in northern Colombia. Exploration
targets are primarily of Early Miocene age, but the area may also have potential in older reservoirs
(Eocene, Oligocene, Cretaceous). Existing production in the Guajira basin is biogenic dry gas. No oil or
thermogenic gas has been discovered in the basin to date.
Survey Objectives
The objectives of this reconnaissance survey are:
To determine if a petroleum system for oil and thermogenic gas exists in the basin.
To evaluate the magnitude and extent of the microseepage anomalies.
To establish the composition of the migrating hydrocarbons (oil, condensate, gas).
Guajira Basin, Northern Colombia
Ethane (C2) vs. Propane (C3) / Sorbed Soil Gas Composition
Geochemical Lead / Hydrocarbon Microseepage Survey / Guajira Basin, Northern Colombia
Line B / Sum (C2-C4)
50.00
140.00
40
FREQUENCY
Oil
120.00
C2
30
Tinka-1
40.00
/ C3
=2
Condensates
20
Propane (C3), ppm
Sum (C2-C4), ppm
100.00
30.00
Aruchara-1
20.00
10
Gas
80.00
0
0
2
4
6
OIL
8
ETHANE / PROPANE
60.00
OIL & GAS
40.00
10.00
Sample Locations
2K-27
2K-26
2K-25
2K-24
2K-23
2K-22
2K -31A
2K -20A
2K -19A
2K -17A
2K -18A
2K-21A
2K -15A
2K -16A
2K -8
2K -9
2K -13A
2K-14A
2K -7
2K-12A
2K -5
2K -6
2K-11A
West
2K-10A
2K -3
2K -4
2K -2
1K -4
2K -1
1K -2
1K -1
0.00
1K -3
20.00
0.00
East
0.00
50.00
500.00
100.00
150.00
Geochemical Lead / Hydrocarbon Microseepage Survey / Guajira Basin, Northern Colombia
Line C / Sum (C2-C4)
BIOGENIC GAS
C1/(C2+C3)
Sopresa-1
200.00
CONDENSATE
10.00
L
E
OIL
I
Guajira Basin, Colombia
Geochemical
Lead Near Previously
Drilled
Hole
Isotopic
Composition
of Sorbed
Soil Dry
Gas
SO-1A
SO-4A
SO-7A
SO-10A
SE-5A
SO-4M
SO-7M
SO-10M
S-1A
L-68A
L-65A
L-64A
A-33A
A-32A
A-28A
A-23A
A-20A
L-62A
A-14A
L-59A
A-11A
A-8A
L-56A
A-5A
L-53A
A-2A
L-50A
L-32
L-47A
L-44A
L-41A
L-38A
L-29A
L-35A
L-26A
L-23A
L-20A
L-17A
L-14A
H
Sample Locations
350.00
Santa Ana-1
East
A
C
D
E
F
G
H
I
J
K
SINGLE DRY GAS
MIXED DEEP GAS
100.00
West
300.00
Guajira Basin, Northern Colombia
100.00
300.00
0.00
250.00
Hydrocarbon Composition, Sorbed Soil Gas
C1/(C2+C3) vs. C2/(C3+C4)
1000.00
400.00
Sum (C2-C4), ppm
200.00
Ethane (C2), ppm
Ethane - Propane Correlation for Sorbed Soil Gas
Geochemical Lead Near Previously Drilled Dry Holes
C
A
J
K
G
LEGEND
Anomaly A
Southwest of Sorpresa-1
Sorpresa-1
Tinka-1
Aruchara
Northeast of Riohacha-1
West of Ballena-1
Between Epehin-1 & Maicao-1
Near Manantiales-1
Z1A, Z2jA
ALTERED
F
D
SOURCE ROCK
1.00
0.00
1.00
2.00
C2/(C3+C4)
3.00
4.00
5.00
Hydrocarbon Composition of Selected Microseepage Anomalies
SURVEY LOGISTICS
The surface geochemical reconnaissance survey was conducted along roads and trails across an area of
5400 square kilometers. Samples were collected at 250-1000 meter intervals. Four 2-man crews collected
samples from 598 locations in 12 days. Microbial samples were collected at 20 cm depth; sorbed soil gas
samples were collected at a depth of one meter.
Guajira Basin, Colombia: Isotopic Composition of Sorbed Soil Gas
Guajira Samples
1.
2.
3.
4.
5.
6.
S-1A
A-26A
A-27A
A-29A
A-30A
M-5AB
Genetic characterization of natural
gases by compositional and isotopic
variations (Schoell, 1983). Figure shows
relative concentrations of C2+ hydrocarbons in relation to carbon isotopic composition of methane. Arrows Ms and Md
indicate expected compositional changes due to shallow and deep migration,
respectively. B represents biogenic gas,
M is mixed thermal and biogenic gas. To
represents oil-associated gas, Tc is gas
associated with condensate, and TT
represents thermal dry gas derived from
oil-prone (m) or humic (h) source rocks.
Numbers 1-6 identify Guajira basin
sorbed soil gas samples. Four of the
samples represent oil-assiciated methane, however, samples 4 and 5 may represent coal-derived gases.
6
Legend
5
X
B
X
4
Biodegrated North Sea Oils
I
X
R1 3
3 Ring/2-Ring
Carbonate Source Oil
North Sea Clastic Marine Shale
C
X
2
Nonmarine Lacustrine /
Deltaic / Paralic Sources
A
X
X
X
1
0
0
10
20
30
40
50
60
API Gravity
A crossplot of API Gravity against fluorescence parameter R1, approximate equal to the 3-Ring/wRing intensity ratio, for oils derived from a variety of source types (Barwise and Hay, 1996). The red
dashed line is the North Sea API Gravity versus R1 correlation for non-degraded oils. Letters refer to
specific microseepage anomalies in the Guajira basin. The data suggest that anomalies A and C (Oca
fault zone) and anomaly F (Aruchara) may be associated with higher gravity oils than anomalies B
(Oca fault zone) and I (central area).
CONCLUSIONS
The results of this reconnaissance surface geochemical survey of the Guajira basin support the
following conclusions:
One, possibly two, petroleum systems exist in addition to the previously known biogenic gas
hydrocarbon system.
Oil and oil-associated gas generation and migration have occurred in the basin. The presence of oil and associated thermogenic gas is documented by sorbed soil gas data, carbon
isotopic composition of methane and ethane, fluorescence analysis of soil extracts, and gas
chromatography of selected solvent extracts.
The principal microbial and soil gas anomalies occur in the southwestern and south-central
parts of the basin. Seepage is especially strong near the Oca fault zone.
The survey identified a number of geochemical leads that warrant additional geological,
geophysical, and geochemical evaluation.
PANEL 2
QLC BLOCK, EASTERN VENEZUELA BASIN - PROSPECT EVALUATION
25
N 1083000 m
70
167
3DL-23
5
3DL-25
N 1081000 m
NL-113
156
3DL-22
133
74
NL-121 121
3DL-21
NL-114
122
3DL-20
103
3DL-24
102
125
208
NL-101
NL-102
209
126
NL-131
151
197
93
NL-122
NL-115
N 1080000 m
191
NL-116
222
NL-134
NL-142
93
142
NL-143
NL-135
N 1079000 m
NL-124
50
NL-118
146
149
102
NL-136
NL-126
65
NL-145
NL-137
CPZ-8S
65
31
NL-107
130
NL-127
NL-120
109
124
199
NL-146
NL-138
NL-128
V6-37
115
143
113
109
NL-148
NL-130
V3-10
STR-9
88
21
109
V3-9
V4-18
149
10
NL-149
N 1076000 m
76
NL-150
V3-8
96
NL-151
V4-17
141
V5-28
STR-10131
148
NL-60
145
NL-61
NL-75
NL-76
145
113
V9-34
LVF-2
STR-11
68
V5-27
LVF-19
152
LVF-18
V7-32
55
LVF-17
LVF-16
180
NL-34
NL-63
75
211
NL-35
135
280
120
VZ-29S
NL-95
59
NL-36
66
NL-78
V5-26
V6-30
71
151
145
73
V3-7
V4-16
V5-25
V6-29
V7-29
V7-30
NL-85
83 64
16
61
NL-100
NL-97
460 m62
CLIFF-N1
V9-N-CLIFF
CLIFF-N2
39
V9-29
95
NL-6
34
NL-18
192
36
NL-19
94
67
V12-30
V11-30
NL-7
NL-29
125
NL-38
67
CLIFF-N4
177
NL-30
90
97
VZ-103S
V3-6
NL-152
N 1074000 m
25
104
NL-153
V3-5
VZ-102S
N 1073000 m
104
111
V4-15
V5-24
73
V6-28
34
VZ-30S
72
120
V4-14
V5-23
102
GOS-1A
GOS-1
78
V3-4
44
133
V3-3
V4-12
V5-21
64
131
V3-2
V4-11
V6-27
112
75
V5-22E
V4-13
82
16
41
V7-28
V8-28
NL-20
29
24
25
V13-NCL
35
36
6
V11-29
V12-29
V13-29
V14-29
V15-29
167
38
V8-27
V6-25
V7-26
51
49
35
V9-27B
V9-27A
63
117
V8-26
V9-26
UTM Northing (meters)
V12-28
V9-25
V8-25
VG-2S
64
V11-27
38
V13-28
60
25
V12-27
V13-27
24
41
V14-28
V15-28
37
V14-27
13
NL-9
48
V16-29
28
V16-28
70
V17-28
48
23
48
V16-27
V17-27
L1-31
65
V15-27
61
51
44
54
33
54
58
39
17
V11-26
V12-26
V13-26
V14-26
V15-26
V16-26
V17-26
L1-30
79
49
19
56
V11-25
V12-25
V13-25
33
V14-25
38
60
14
33
V15-25
V16-25
L1-29
V17-25
V10-25
171
49
56
101
21
V5-20
V6-24
V7-24
V8-24
V9-24
72
105
62
47
140
41
65
V3-1
V4-10
V5-19
V6-23
V7-23
V8-23
V9-23
3
L2-31
V10-27
V10-26
34
400 m
V10-24
N 1072000 m
87
V11-28
50
VG-1S
93
40
V7-25
46
33
V10-28
83
V7-27
124
V6-26
NL-8
92
NL-39
V10-29
67
70
V9-28A
V9-28
32
25
V12NCLCLIFF-N3
37
V10-30
30
NL-5
99
NL-21
63
NL-65
VZ-27S
40
30
NL-17
NL-37
55
53
54
NL-4
150
NL-22
34
NL-16
67
NL-28
44
44
75
NL-96
NL-15
NL-27
147
NL-84
94
65
NL-99
NL-23
85
NL-51
LA VIEJA DEEP
110
128
78
NL-26
NL-50
70
14
NL-3
76
NL-14
NL-49
NL-64
37
V7-31
V6-31
174
NL-48
130
NL-112
139
NL-13
93
NL-25
56
V7-33
109
28
NL-2
NL-24
120
LVF-1
82
VZ-26
NL-111
67
NL-33
115
VZ-25
NL-62
209 105
VZ-21
VZ-22
65
VZ-18
80
LVF-3
VZ-3 VZ-13
VZ-6VZ-28 132 VZ-23
LVF-4
VZ-11
LVF-5
LVF-14
LVF-22
VZ-24
VZ-10
152 166
52 VZ-20
145 VZ-5
VZ-4VZ-17
103 73 LVF-6
VZ-1
71
VZ-19
VZ-14
LVF-13
42
V9-33
LVF-21
171
V8-33
VZ-7
VZ-12
LVF-8 LVF-7
133
112
127
VZ-15
LVF-9
VZ-9 152
LVF-10
LVF-12
LVF-20VZ-2
NL-77
VZ-8
LVF-11 VZ-16
74
88
LVF-23
135
123
NL-47
79
120
120
NL-1
98
NL-12
91
85
142
67
132
V8-34
LVF-15
126
120
NL-11
211
NL-32
129
NL-74
V9-35
NL-98
NL-31
74
NL-46
81
V9-36
NL-94
114
141
NL-45
NL-59
98
320 m
120
NL-110
110
59
V9-37
92
91
VZ-104S67
N 1075000 m
125
NL-72
NL-73
NL-93
96
NL-10
NL-44
68
NL-58
146
3DL-1
83
STR-7
STR-6
132
V10-39
92
101
81
V5-29
129
V12-40
124
V9-38
114
138
81
NL-129
NL-139
NL-147
STR-5
127
NL-57
NL-92
3DL-2
161 NL-109
157
105
185
NL-91
118
3DL-3
165
V5-30
N 1077000 m
V6-38
V12-41
138
NL-43
NL-71
113
3DL-4
113
159
NL-56
V9-39
V5-31
80
V12-42
158
NL-83
104
V5-32
219
58
NL-42
119
NL-70
V9-40
107
NL-90
171
89
143
81
V5-33
65
157
NL-119
3DL-12
3DL-13 72 NL-108
V12-43
152
NL-69
198
3DL-5
146
3DL-14
139
186
NL-41
49
NL-55
NL-82
117
3DL-15NL-106
247
NL-125
NL-144
116
118
NL-40
70
45
87
3DL-16 NL-105
NL-117
NL-81
131
NL-89
138
3DL-6
217
90
49
69
186
N 1078000 m
102
NL-123
104
NL-54
NL-68
128
NL-88
158
3DL-7
173
V11-44
V10-44
42
90
NL-80
3DL-11
259
NL-104
91
43
NL-53
84
118
NL-87
150
NL-103
131
3DL-17
118
146
3DL-18
3DL-19
66
NL-132
CPM-1X
NL-133
135
3DL-9
3DL-8
164
132
31
84
NL-67
NL-86
144
3DL-10
143
NL-140
NL-141
NL-52
NL-66
45
NL-79
99
N 1082000 m
15
45
91
V12-24
V11-24
43
29
V14-24
V13-24
68
77
44
78
V11-23
V12-23
V13-23
V14-23
96
31
54
L1-28
73
V17-A24
V17-B24
46
V15-24
V16-24
57
V15-23
30
L2-30
48
39
L2-29
L3-29
104
80
L2-28
L3-28
37
49
25
132
29
V16-23
V17-23
L1-27
L2-27
L3-27
L5-28
N 1071000 m
37
37
63
96
56
V5-18
V6-22
V7-22
V8-22
V9-22
59
25
69
V4-8
V5-17
V6-21
52
31
V4-7
V5-16
87
N 1070000 m
V4-6
N 1069000 m
230
220
210
200
190
180
170
160
150
460140
m
130
120
110
CM-1052
100
90
80
70
60
50
40
30
SCE-1
20
10
N 1066000 m
N 1065000 m
N 1064000 m
N 1063000 m
N 1062000 m
36
90
71
73
67
75
50
30
V10-21
V11-21
V12-21
V13-21
V14-21
V15-21
V16-21
V17-21
L1-25
L2-25
L5-25
20
79
46
54
V9-20
V10-20
V11-20
V12-20
34
V8-19
V7-19
V9-19
64
60
49
47
V5-14
V6-18
V7-18
V8-18
18
99
30
V10-19
V11-19
V12-19
70
59
55
22
V9-18
V10-18
V11-18
V12-18
68
V13-20
360 m
44
V13-19
39
V13-18
71
33
36
49
42
26
75
61
89
49
V5-13
V6-17
V7-17
V8-17
V9-17
V10-17
V11-17
V12-17
V13-17
43
115
48
43
V5-12
V6-16
V7-16
60
63
V4-2
V5-11
24
71
V4-1
V5-10
V8-16
52
77
V6-15
V7-15
50
46
V6-14
45
69
V5-9
V6-13
45
V6-12
38
V10-16
20
100
V8-15
V10-15
V11-15
33
V8-14
V9-14
45
13
52
V8-13
V9-13
47
16
V7-12
36
V10-14
V12-B16
44
19
V12CLIFF
V12-15
VAC-1
29
V11-14
38
42
V10-13
V11-13
99
26
134
V11-16
122
V9-15
41
V7-14
28
V9-16
75
V7-13
52
92
V5-8
V10-12
65
V14-19
39
41
93
V15-17
V14-N16
101
54
V14-16
V15-16
57
V14-15
63
21
60
V16-19
L1-23
V17-19
120
V15-18
31
23
V17-20
L1-24
30
V16-20
V15-19
92
3
24
76
V15-20
V14-18
V14-17
18
59
742
42
L1-22
V17-18
V17-A18
V16-18
37
43
20
V16-16
V17-16
L1-20
52
29
40
L3-24
L4-24
L5-24
99
L2-23
50
55
L5-22
25
12
L4-21
12
66
L2-20
L3-20
L5-23
45
L4-22
80
L3-21
L2-21
77
L4-23
L3-22
99
280 m
62
82
L3-23
42
L2-22
60
36
V17-17
L1-21
11
V16-17
L5-26
45
L2-24
L5-21
49
28
L5-20
L4-20
62
48
25
31
4
52
30
V16-15
V17-15
L1-19
L2-19
L3-19
L4-19
L5-19
V15-S15
57
33
V13-14
50
64
V12-12
V11-12
28
V14-20
V13-15
V12-14
V12-13
73
30
V13-16
78
124
V14-14
V15-14
43
51
32
V13-13
V14-13
V15-13
22
25
38
49
V16-14
V17-14
L1-18
L2-18
33
36
71
L3-18
L4-18
L5-18
81
31
22
15
40
45
31
V16-13
V17-13
L1-17
L2-17
L3-17
L4-17
L5-17
22
93
23
42
29
70
20
32
37
29
58
V13-12
V14-12
V15-12
V16-12
V17-12
L1-16
L2-16
L3-16
L4-16
L5-16
VACA CAPAYA
V9-12
V8-12
L5-27
117
V15-22
43
13
64
24
L2-26
22
V14-22
63
V8-20
44
65
V6-19
V9-21
26
24
V17-22
L1-26
92
V13-22
84
80
V11-22
V4-4
52
N 1067000 m
94
V7-20
V4-5
V4-3
N 1068000 m
57
V8-21
53
V16-22
51
V12-22
35
53
V10-22
VACA MERECURE
62
V6-20
72
V5-15
101
V7-21
34
78
42
L4-27
V10-23
49
V4-9
V13A-12
97
21
60
19
V5-7
V6-11
V7-11
V8-11
37
34
83
42
V5-6
V6-10
V7-10
V8-10
44
36
34
39
41
42
28
34
66
88
46
51
40
76
V9-11
V10-11
V11-11
V12-11
V13-11
V14-11
V15-11
V16-11
L1-15
V17-11
L2-15
L3-15
L4-15
L5-15
39
55
33
59
36
98
16
61
39
45
29
33
24
22
V9-10
V10-10
V11-10
V12-10
V13-10
V14-10
V15-10
V16-10
V17-10
L1-14
L2-14
L3-14
L4-14
L5-14
51
42
36
71
54
33
51
92
23
V5-5
V6-9
V7-9
V8-9
V9-9
V10-9
V11-9
V12-9
V13-9
48
8
43
73
V5-4
V6-8
V7-8
V8-8
35
65
V5-3
V6-7
50
39
V5-2
V6-6
79
21
V5-1
V6-5
21
23
V5-S1
V6-4
42
48
26
50
36
30
32
38
V15-9
V16-9
V17-9
L1-13
L2-13
L3-13
L4-13
L5-13
46
96
26
76
33
27
51
56
24
37
26
50
72
52
V9-8
V10-8
V11-8
V12-8
V13-8
V14-8
V15-8
V16-8
L1-12
V17-8
L2-12
L3-12
L4-12
L5-12
23
40
42
40
36
58
54
54
37
43
70
20
24
23
26
V8-7
V9-7
V10-7
V11-7
V12-7
V13-7
V14-7
V15-7
V16-7
L1-11
V17-7
L2-11
L3-11
L4-11
L5-11
73
42
24
29
177
148
64
82
48
53
2930
32
34
115
27
V7-6
V8-6
V9-6
V10-6
V11-6
V12-6
V13-6
V14-6
V15-6
V16-6
V17-6
L1-10
L2-10
L3-10
L4-10
L5-10
114
V7-7
440 m
73
V14-9
VZ-201S
SVA-1
36
16
38
18
53
48
84
52
32
33
79
85
50
30
26
39
V7-5
V8-5
V9-5
V10-5
V11-5
V12-5
V13-5
V14-5
V15-5
V16-5
L1-9
V17-5
L2-9
L3-9
L4-9
L5-9
50
31
31
126
54
65
40
57
59
35
25
17
15
19
18
V8-4
V9-4
V10-4
V11-4
V12-4
V13-4
V14-4
V15-4
V16-4
V17-4
L1-8
L2-8
L3-8
L4-8
L5-8
21
V8-3
78
20
V9-3
V10-3
25
N 1061000 m
12
30
V8-2
V9-2
39
82V11-E3
V11-N2
35
52
61
V12-3
25
V13-3
V14-3
58
46
V16-3
V17-3
L1-7
61
69
11
V14-2
V15-2
V16-2
2
95
V17-2
L1-6
74
V14-1
5
47
91
36
V13-2
V15-3
V12-2
36
V9-1
V8-S1
64
V15-1
50
48
2
L3-7
L4-7
L5-7
36
L2-7
ISLA
62
50
53
49
L2-6
L3-6
L4-6
L5-6
61
40
16
34
V16-1
L1-5
L2-5
L3-5
93
5
V9-S1
L2-4
15
L3-4
106
51
N 1060000 m
V10-2
15
V8-1
V9-S2
V8-S2
N 1059000 m
N 1058000 m
E 366000 m E 367000 m E 368000 m E 369000 m E 370000 m E 371000 m E 372000 m E 373000 m E 374000 m E 375000 m E 376000 m E 377000 m E 378000 m E 379000 m E 380000 m E 381000 m E 382000 m E 383000 m E 384000 m E 385000 m
UTM Easting (meters)
Scale 1:50000
0 km
1 km
2 km
3 km
4 km
5 km
Geologic Setting
The Quiamare La Ceiba (QLC) block in the Eastern Venezuela basin lies within a structurally complex zone
just beyond the western edge of the prolific petroleum province known as the El Furial trend. The QLC concession is located in the Santa Rosa structural block and includes the Quiamare, La Vieja, La Ceiba, and
Tacata oil fields. Production is primarily from the Milocene Oficina and Eocene Merecure formations. Heavy
oil is present in the shallow reservoirs of the old La Vieja field; light oil and condensate characterize deeper
reservoirs.
Tacata Area: Example of Integration Between Geology and Microbial Data
South Edge
Tacata Field
250
North Edge
Tacata Field
4 km
250
30
00
20
TAR 1
200
TAG 12
Microbial Values
L17-39
L17-38
L17-37
L17-36
L17-35
L17-34
L17-33
L17-32
L17-31
L17-30
L17-29
L17-28
L17-27
L17-26
L17-25
L17-24
L17-23
L17-22
L17-21
L18-9
L17-20
L17-19
L17-18
L18-8
L18-7
L17-17
L17-16
L17-15
L17-14
L18-10
L18-8B
L18-8A
L18-8C
L18-6
L18-5
L18-4
L18-3
L18-2
L18-1
24
00
00
0
South
M icrobial Values
00
00
24
00
13
14
3000
16 Ma event
TWTT (ms)
Datum =+500m
TAR 1
00
Sample Locations
30
00
30
North
40
00
50
30
100
50
30
0
24
00
24
Smoothed Microbial Values
12
150
100
0
00
30
30
00
200
500M West
150
Sm oothed M icrobial Values
North to South microbial profile across Tacata field illustrating the strong microseepage anomaly associated
with the field. The accompanying seismic section and structure map illustrate the structural complexity of
the Tacata area.
Survey Objectives
The objectives of the QLC geochemical survey are:
Determine the magnitude and lateral extent of hydrocarbon microseepage anomalies associated
with the various exploration prospects, and with the La Vieja and Tacata fields.
High-grade the major prospects based on their probable hydrocarbon charge.
Determine the composition of the migrating and/or reservoired hydrocarbons.
Identify geochemical leads that warrant further geologic and seismic study.
Survey Logistics
A geochemical survey was conducted over a 575 square kilometer area in the eastern half of the QLC block.
Surface conditions ranged from open grassland in the eastern part of the ara to dense, almost impenetrable
jungle in the west. Samples were collected at 500-1000 meter intervals in a grid pattern. Sample sites were
located with hand held 12 channel Garmin GPS units. Two to three 3-man crews collected 1587 microbial
samples and 200 sorbed soil gas samples in 60 days. Microbial samples were collected at 20 cm depth; sorbed
soil gas samples were collected from a depth of one meter.
CONCLUSIONS
The results of microbial and sorbed soil gas analyses support the following conclusions:
The most intense microseepage is associated with the surface expressions of the Urica fault
near Urica and extending west to just north of La Vieja field.
Significant microseepage anomalies are associated with the La Vieja Deep prospect and the
central part of the Vaca Merecure prospect. There is no geochemical anomaly associated
with the Vaca Capaya prospect.
A cluster of microseepage anomalies extends E-W along the acial portion of Tacata field. The
absence of a single large anomaly -- one coincident with the mapped closure -- suggests that
the trap is either not fully charged, or more compartmentalized than seismic data suggest.
PANEL 3
APPLICATIONS FOR FIELD DEVELOPMENT AND PRODUCTION
Because hydrocarbon microseepage is predominantly vertical, the extent of the anomaly at the surface can
approximate the productive limit of the reservoir at depth. The detailed pattern of microseepage over a producing field can also reflect reservoir heterogeneity and distinguish hydrocarbon-charged compartments from
drained or uncharged compartments. Additionally, since hydrocarbon migration is dynamic, seepage patterns
change rapidly in response to production-induced changes. Evidence for such changes are identified with
detailed soil gas, microbial, and/or fluorescence surveys. When such surveys are repeated over the life of a
producing field or waterflood project, the changes in seepage patterns can reflect hydrocarbon drainage.
Los Manuelas Field, Western Venezuela
The Los Manuelas Field is located in the southwestern
Maracaibo-Catatumbo basin, and occurs on the crest of a
tightly folded anticline bounded on the east side by a westdipping reverse fault. The principal reservoirs occur in the
Eocene Mirador, but other reservoirs occur in the Oligocene,
Paleocene, and Cretaceous. The field was discovered in 1930
and is now largely depleted. The principal objective of the
microseepage survey was to determine (1) if the field has a
surface geochemical expression, and (2) to document the
geochemical evidence for the likely presence of bypassed
pay in the old field, and (3) and the possible field extension
to the north beyond the present productive limits. For comparison with the old oil field, we also acquired samples
across a recently discovered and as yet undeveloped field
(La Palma) nearby.
Old Oil Field - Microseepage Pattern
100
75
55
Microseepage values are generally low over the old (1930) oil field, however, the presence of
several well-defined microbial anomalies may indicate location of by-passed pay. Note that
most of the anomalies terminate against the trapping fault at east edge of the field.
The results of the microbial and sorbed soil gas analyses
form document very strong hydrocarbon microseepage over
the new field, and lower but still significant microseepage
over portions of the Los Manuelas field. The relatively low
microseepage values over the old field are believed to
reflect its long production history and lower reservoir pressures. High seepage values from over the northeast portion
of Los Manuelas may reflect its shorter production history
and greater remaining potential. New productive wells have
been drilled within several of these microseepage anomalies,
one of which is illustrated on the seismic section to the right.
Santa Lucia Field, Middle Magdalena Valley Basin, Colombia
The Santa Lucia field is a small 3-well field situated on a faulted anticline in the Middle Magdalena Valley
basin, central Colombia. The field produces 19-21 API Gravity oil and some associated gas from Lower Tertiary fluvial sands in the Esmeraldes-La Paz formations. At the time of the microseepage survey, 3 wells were
producing 150-300 BOPD from depths of 2500-2600 meters. The survey area encompassed approximately
16km2, and consisted of low-lying farm and pasture land. Soil samples were collected at 250 meter intervals
in a grid pattern. The objectives of the Santa Lucia microseepage survey were:
Determine magnitude and areal extent of hydrocarbon
microseepage anomalies associated with the oil field.
Identify areas that may represent by-passed pay or leakage
from an undrained reservoir compartment.
Determine the composition of the migrating and/or
reservoired hydrocarbons.
Determine if the fault between wells SL-1 and SL-2 is a
sealing fault.
Correlate hydrocarbons from surface microseepage anomaly with the reservoired hydrocarbons.
The results of the microbial and adsorbed soil gas analysis documented the presence of strong microseepage
at a number of locations north and east of the producing wells. The most prospective microseepage anomaly
occurs as a 500-800m wide zone along the eastern edge of the field, between wells SL-1 and SL-2. The data
suggest that this represents by-passed oil, or possibly oil from an untested reservoir compartment.
Gas chromatographic and fluorescence analysis of crude oil from the producing well were correlated with
results of similar analyses performed on solvent extracts of soil from the microseepage anomaly. Chromatographic data support the conclusion that SL-1 oil is not in communication with oil from the SL-2 reservoir,
and that the intervening fault is a sealing fault. Fluorescence characteristics of the crude oils independently
support this conclusion and show a high degree of correlation with the soil extract data.
N 1,359,000m
-9.50
Map 3
Microbial Values Image Map
0
-9.50
0
INDEX MAP - SANTA LUCIA FIELD
1800000
160
-9.000
S8-17 S9-16
SANTA
LUCIA-2
2040
S7-14
540
S8-16
S8-15
400
S6-15
340
360
2080
S10-11
S8-14 S9-13
S7-12
S6-14
520
300
S7-11
380
S11-11
S6-13
S7-10320 S8-12
240
PC-81-10
S6-12
2060
S6-11
500
2000
S8-11
S8-10
S6-10
S2-10
2080
300
S2-9
2020
-9.0
00
S1-7
2040
-8.5
00
S2-6
S6-8
S3-5
480
S1-4
PT-96-004
2060
S10-7 S11-7
S7-1
S1-2
S2-1
2080
S3-4A
S9-3
340
360
2200
L85-130
-8.5
2680
S11-5
2100
2120
S15-7 380
S15-6
2040
S16-1
S6-2
S15-3
S16-5
S16-6
S8-1
S3-15A
S3-14A
S16-9
S16-10
2080
2620
260
2160
275
325
375
425
475
L85-152
S15-1
S16-7
S16-8
S6-1
2100
EG-778
2120
2600
2180
340
225
2060
S3-10A
2100S3-12A
2100
375
425
475
275
325
375
425
Wavelength (nm)
S9-16 Dilution 1:1
475
25
23
20
18
15
13
10
8
5
3
0
225
475
25
23
20
18
15
13
10
8
5
3
0
225
S9-15 Dilution 1:1
0
S15-2
S3-11A
420
SL-3
60
325
275
325
375
425
Wavelength (nm)
475
45
Wavelength (nm)
S16-3
S15-4
400
280S16-4
S3-13A
S3-1A
-8.0
00
2640
MUZANDA-1
S16-2
S15-5
S9-1
S4-1
S3-9A
S3-2A
320
SL-2
75
15
2160
S15-9
S15-8
275
Wavelength (nm)
2140
300
2020
360
S15-10
2140
S3-8A
S3-3A
2120
300
2660
S11-3
S11-1
S9-2
S8-2
S6-3
225
SL2 Dilution 1:200000
30
320
S11-4
2180
S10-2 S11-2
S10-1
440
S3-7A
280
N 1,349,500m
N 1,349,000m
2160
00
2080
S11-6
S10-5
S10-4
S10-3
340
S4-2
S3-5A
S1-1
S9-4
S8-3
S6-4
2140
S3-6A
S9-5
S8-5
2160
S8-4
2120
-8.500
S2-2
N 1,350,000m
S9-8S10-6
S9-7
S9-6
S8-6
S7-3
S7-2
S2-3
S1-3
260
S7-4
SL-1
460
S2-4
2060
N 1,350,500m
S8-8
2000
S6-6
S3-2
S3-1
0
125
113
100
88
75
63
50
38
25
13
0
225
SL-1
90
1020
340
S11-8
S10-8
S9-9
S8-9
S7-7
S7-6
S6-7
2100
S3-3
S2-5
S1-5
PC-81-6
320
S7-5
S8-7
SANTA LUCIA-1
S3-4
S2-7
S1-6
N 1,351,000m
S6-9
S3-6
S2-8
N 1,351,500m
105
400
2140
S9-10
280
-9.0
00
N 1,352,000m
360
2120
S11-9
S10-9
S9-11
2040
S7-9
S7-8
A "C"
FALL
260
N 1,352,500m
120
S11-10
S8-13 S9-12 S10-10
2220
2020
SL-1, SL-2, & SL-3 NORMALIZED
380
2060
S11-12
2100
PC-81-4
2040
Tr8X8
Tr7X4
2020
320
S11-13
280
220
N 1,353,000m
Tr6X8
PT-96-005
2000300
2260
S10-12
S9-14
260
-9.000
L85-152
1020
M7815
S11-16
S11-15
S11-14
S10-13
S9-15
2240
S7-13
30
2280
280
S10-17
S11-17
S10-16
S10-15
SL-2
S10-14
S6-17
S27S28
S6-16
Intensity
S7-15
S9-18
0
S9-17
-8.00
S7-16
S26
15
420
260
S9-20
S9-19
S8-19 560
S7-17
S6-20
S25
240
60
Intensity
S11-19
S11-18
S10-18
360
S12-1
SL-3
S7-19
S8-22
S8-21 S8-20
S7-18A
S7-18
00
S6-21
-8.0
S6-19
S6-18
S24
220
2020
S9-16
S10-11
240
Fingerprinting of Santa Lucia oils suggests SL1 oil not in fluid communication with SL2 and SL3 oils. Upper figure represents a C7 Oil Transformation
Star Diagram; lower figure shows Fluorescence Data
25
23
20
18
15
13
10
8
5
3
0
225
S10-11 Dilution 1:1
Intensity
FALL
A "A"
S10-19
580S9-21
S8-23
S6-23
S6-22
2020
S23
L85-130
SL-2, S9-15, S9-16, S10-11 NORMALIZED
S9-15
90
75
45
Tr1X2
Tr5
340
SL-2
120
105
Intensity
S1
S7-20
S6-24
-8.500
S9
S19
S22
PC-81-8
-9.0
00
S2
S8
S18
S20
S21
PC-81-2
N 1,354,500m
-9.00
0
S7
S17
N 1,355,000m
440
2300
S12-2
SANTA LUCIA-3
S30
S7-21
S10-20
S9-22240
S8-24
S29
S11-20
S6-25
S3
S16
N 1,355,500m
GM000002
320
S12-3
S11-21
S10-21
S9-23
150
GM000001
Tr2
GM000003
S10-22
S8-25
S7-22
S31
S4
S6
600 S11-22
S9-24
S32
220
S5
S10
S14
N 1,353,500m
2320
S13-1
S33
S7-23
L85-128
S11
S13
S12
1800000
S15
N 1,354,000m
460
-9.500
0
1600000
Tr3X2
Tr4X2
280
S12-4
S11-23
135
2340
PT-96-006
M-11-78
1980
"B"
300
S9-25
-8.50
800000
400000
200000
1400000
LA
S13-3
S13-2
S7-24
S34
10
1200000
FAL
S13-4
S35
0
1000000
260
S13-5
S12-6
S12-5
S11-24
S7-25
1020
0
S12-7
S11-25
620
S9-27A
S9-27
S9-26
S36
20
Intensity
S37
S9-28
S9-28A
S40
S39
S38
50
40
30
2000
M-78-07
2090 480
S13-6
S12-8
-8.50
80
70
800000
S14-5
240
60
N 1,356,000m
Reservoir Oil Fingerprinting
640
Intensity
220
Map 3 Microbial Values Image Map.srf
1400000
BOGOTA
600000
Soil-to-Oil Correlation
-9.000
120
110
100
90
00
-8.5
N 1,356,500m
00
-10.0
L-84/85-126
130
600000
N 1,357,000m
660
140
VALLEDUPAR
DPTO
CESAR
1000000
N 1,357,500m
1200000
N 1,358,000m
150
VALLEDUPAR
1600000
N 1,358,500m
275
325
375
425
Wavelength (nm)
275
325
375
425
Wavelength (nm)
475
Comparison of fluorescence fingerprint of SL2 oil with soil extracts
from nearby seepage anomaly shows strong correlation with SL2 oil.
2120
360
280
400
2080
N 1,348,500m
380
2580
2200
300
220
2140
400
320
N 1,348,000m
E 1,041,000m
E 1,041,500m
E 1,042,000m
E 1,042,500m
E 1,043,000m
E 1,043,500m
E 1,044,000m
E 1,044,500m
E 1,045,000m
E 1,045,500m
E 1,046,000m
E 1,046,500m
E 1,047,000m
E 1,047,500m
E 1,048,000m
E 1,048,500m
E 1,049,000m
E 1,049,500m
E 1,050,000m
E 1,050,500m
E 1,051,000m
E 1,051,500m
E 1,052,000m
E 1,052,500m
Scale 1:25,000
0m
500 m
1,000 m
1,500 m
2,000 m
2,500 m
PANEL 4
LANCONES BASIN, PERU - RECONNAISSANCE SURVEY
Geologic Setting
The Cretaceous Lancones basin is one of a number of rift-related marginal basins in western South America. It
is located in northwestern Peru and is bordered by the Amotape-Tahuin Massif (La Brea Mountains) on the
west and volcanic arc strata on the east. Sediments in the basin are primarily of Upper Cretaceous and
Cenozoic age, however Paleozoic rocks are present in the Paito area. Surface anticlines in the northern part
of the basin represent potential exploration leads and prospects.
Survey Objectives
The objectives of this reconnaissance survey are:
to determine the presence of a petroleum system for oil and/or thermogenic gas.
to high-grade the major anticlines and other exploration leads on the basis of likely hydrocarbon
charge.
to document the composition of the migrating hydrocarbons (oil, condensate, or dry gas).
to identify geochemical leads that warrant geologic and seismic evaluation.
Survey Results
The results of this reconnaissance geochemical survey:
BPZ
Lancones Project / Northern Peru
Legend
C1/(C2+C3) vs. C2/(C3+C4) / Sorbed Soil Gas Analysis
1000.00
Totoras Anticline
Jabomillos Anticline
Galinazos
document the presence of at least one,
possibly two, petroleum systems in the basin.
Anticline 2
Anticline 3
The Gap
Abejas Well
Olympic Gas Field
BIOGENIC GAS
100.00
C1/(C2+C3)
identified several anticlines or portions of anticlines
with strong hydrocarbon microseepage anomalies.
SINGLE DRY GAS
MIXED DEEP GAS
CONDENSATE
10.00
the composition of the migrating hydrocarbons ranges
from thermogenic dry gas to gas associated with light
oil and/or condensate.
OIL
ALTERED
SOURCE ROCK
1.00
0.00
1.00
2.00
C2/(C3+C4)
3.00
4.00
5.00
SUMMARY AND CONCLUSIONS
The results of recent microbial and soil gas surveys in Venezuela, Colombia, and Peru document the value of
hydrocarbon microseepage data for high-grading prospects and aiding firld development projects. These surveys were conducted in the Eastern Venezuela basin, the Maracaibo-Catatumba basin in western Venezuela,
the Guajira and Cesar Rancheria basins in northern Colombia, the Middle Magdalena Valley basin in central
Colombia, and the Lancones basin in Peru. Results from the underexplored Lancones basin identified structures that warrant additional study due to strong hydrocarbon indications. The Guajira survey documented
previously unrecognized oil potential in a basin known only for its biogenic dry gas. Results from eastern Venezuela and Cesar Rancheria successfully discriminated prospects on basis of probably hydrocarbon charge.
Surveys over two old oil fields in western Venezuela and in the Middle Magdalena Valley identified bypassed
pay and several new drilling opportunities.
High-resolution microseepage surveys offer a flexible, low-risk and low-cost environmentally friendly technology that not only complements traditional geologic and seismic data, but adds value to such data. Properly
integrated with other exploration data, their use has led to discovery of new reserves and drilling fewer dry
or marginal wells.
SELECTED REFERENCES
Klusman, R.W., 2002, The interpretation and display of surface geochemical data, in D. Schumacher and L.A. LeSchack, eds., Surface Exploration
Case Histories: AAPG Studies in Geology No. 48, and SEG, Geophysical Reference Series No. 11, p. 1-24.
Lopez, J.P., D.C. Hitzman, and J. Tucker, 1994, Combined microbial, seismic surveys predict oil and gas occurrence in Bolivia: Oil and Gas Journal,
24 October 1994, p. 67-69.
Rice, G.K., J.Q. Belt Jr., and G.E. Berg, 2002, Soil-gas hydrocarbon pattern changes during a West Texas waterflood, in D. Schumacher and L.A.
LeSchack, eds., Surface Exploration Case Histories: AAPG studies in Geology No. 48 and SG Geophysical Reference Series No. 11, p. 157-174.
Schumacher, D., 1996, Hydrocarbon-induced alteration of soils and sediments, in D. Schumacher and M.A. Abrams, eds., Hydrocarbon Migration
and its Near-Surface Expression: AAPG, Memoir 66, p. 71-89.
Schumacher, D., 1999, Surface geochemical exploration for petroleum, in T. Beaumont and N. Foster, eds., Exploring for Oil and Gas Traps: AAPG,
Treatise of Petroleum Geology Handbook, p. 18-1 to 18-27.
Schumacher, D., 2010, Integrating hydrocarbon microseepage data with seismic data doubles exploration success: Proc. Indonesian Petroleum
Association, 34th Annual Conference, IPA-10-G104, 11pp.
Schumacher D., and M.A. Abrams, edgs., 1996, Hydrocarbon Migration and its Near-Surface Expression: AAPG, Memoir 66, 445 pp.
Schumacher, D., and L.A. LeSchack, eds., 2002, Surface Exploration Case Histories: Applications of geochemistry, magnetic, and remote sensing:
AAPG Studies in Geology No. 48 and SG Geophysical Reference Series No. 11, 486 pp.
Tucker, J., and D.C. Hitzman, 1994, Detailed microbial surveys help improve reservoir characterization: Oil and Gas Journal, V. 92, no. 23, p. 6568.
ACKNOWLEDGMENTS
I would like to thank the members of Geo-Microbial Technologies (GMT) and GMT International who participated in these surveys, and the exploration companies who have allowed us to show these survey results. Special thanks are due Mc. Lesta Morrison for preparing these poster panels.
PANEL 5