The document provides information on reservoir mapping techniques and workflows. It discusses constructing structure maps, isopach maps, net pay maps, and fault maps to characterize reservoirs based on well log and seismic data. The maps are used for well placement, reserves calculations, and reservoir performance monitoring. Key steps include reservoir correlation, defining flow units, determining fluid contacts, and integrating geological and petrophysical data. The results provide insights into reservoir properties and geometry to promote optimal field development.
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
Reservoir mapping
1.
2. • To demonstrate reservoir
properties in a plan view
projection with objectives to
promote optimal field
development.
• The maps will be used for
well placement, reserves
calculation, reservoir
performance monitoring.
• Mapping is part of reservoir
characterization, therefore
the results of which very
depend on the expert’s
working knowledge in
applied geologic models
8. BASIC CURVE SHAPE OF SP & GR
for facies & sedimentary environment determinations
9.
10. DIP METER
dip patterns and it’s
geologic association
DIPMETER USES :
•Structural dip & fault determinations.
•Facies, type of sands & it’s trends
interpretations (micro resistivity
•Fracture identification
•Sedimentary structure can be
identified with processed Dipmeter or
FMI (formation imaging)
11. FMI fulbore formation micro imager
RAB resistivity at the bit
12.
13. SEISMIC FOR RESERVOIR GEOLOGY
• Aid in :
– Reservoir facies mapping reservoir distribution : lithology,
isopach etc 3D
– Reservoir properties mapping porosity
– Locating / define fluid contacts
– Monitoring fluid fronts 4D
– Sructure & stratigraphic interpretations
• Seismic methods :
– 2D Seismic
– 3D seismic
– VSP
– Well to well seismic
– Time-lapse seismic monitoring etc.
23. Distinctive and Common Sedimentary
Facies Associations
Vertical successions
principally identified
by lithology,
associations and
vertical arrangement
of sedimentary
structures
indicative of
particular
sedimentary
depositional
environments
25. SEQUENCE STRATIGRAPHY CONCEPTS
• Sequence stratigraphy highlights the role of allogenic controls on
patterns of deposition, as opposed to autogenic controls that
operate within depositional environments
– Eustasy (sea level)
– Subsidence (basin tectonics)
– Sediment supply (climate and hinterland tectonics)
29. • A MAPABLE PORTION OF THE TOTAL RESERVOIR
WITHIN WHICH GEOLOGICAL AND PETROPHYSICAL
PROPERTIES THAT AFFECT THE FLOW OF FLUIDS
ARE CONSISTENT AND PREDICTABLY DIFFERENT
FROM THE PROPERTIES OF OTHER RESERVOIR
ROCK VOLUME ( mod. EBANK, 1987)
– A specific volume of reservoir, may be composed of
one or more lithologies and any nonreservoir rock
types
– Correlative and mappable at the interwell scale
– Zonation is recognizable on wireline logs
– May be in communication with other flow unit
30. LEVELS OF
RESERVOIR
HETEROGENETY
(fluviatil rock)
31. GEOLOGICAL AND PETROPHYSICAL DATA
USED TO DEFINE FLOW UNITS
Core Pore Petrophysical Gamma Ray Flow
Core Lithofacies
Plugs Types Data Log Units
Capillary
φ vs k Pressure
5
4
3
2
1
32.
33.
34. Schematic Reservoir Layering Profile
in a Carbonate Reservoir
Flow unit
Baffles/barriers
SA -97A SA -356 SA -71 SA -344 SA -348 SA -37
SA -251 SA -371 SA -346
3150 3150 3100 3100 3250
3200 3150
3100
3200
3150
3200 3200 3150 3300
3250 3200
3150
3250
3250 3250 3200 3250
3300 3250
3200
3300 3300 3250
3350 3300
3250
3350 3350
From Bastian and others
35. E
• BASED ON :
– PRODUCTION TESTINGS the most
reliable methods
– LOGS (electrical logs combined with FDC &
CNL)
– PRESSURE SURVEY pressure gradient
from RFT
– SEISMIC hydrocarbon indications
36.
37. Fluid Contact Determination
with fluid gradient from RFT
Oil
Gra
W
die
at
er
nt 0
G
ra
.36
di
en
7
t0
psi
.4
depth
33
/ft
ps
i/f
t
oil OWC
water
RFT depth
pressure
38.
39. CORRELATIONS
• “Reservoir Correlation” is part of pre-mapping works
of reservoir to locate and trace the lateral
distribution, continuity, geometry of reservoirs and
it’s flow unit.
• Correlation should be carried out based all the
available data, a sedimentological and stratigraphic
model of the reservoirs.
• Some pre-correlation works notes:
– Wireline log will be the basic data and will be calibrated and
integrated with other data analysis results such as core
analysis especially.
– Vertical profile analysis of well data should be carried out
previously to establish the facies, sequences and
sedimentary environment.
– Zonation of lithology and flow unit, and also marker
inentifications should be geologically sound.
– Define the zone top & bottom, zone thickness (gross & net)
etc.
40. Tips for Correlation
• Stratigraphic Cross Section is the best demonstration of a
correlation results.
• The section should show reservoir lateral and vertical facies
changes, markers continuity, missing & repetition sections,
completion & prod. testing notes, etc.
• Good markers can be organic shale, coal/lignite, limestone beds,
glauconite, siderite etc. which has good continuity and
correspond to the geologic events such as maximum flooding,
emmergence etc.
• Start the correlation with the whole log section of individual well,
make zonation based on electro facies then define all markers
and zones of interest. Indicates any missing and repetition
section. Then carry out a detail correlation of objective reservoirs.
• For reservoir connectivity indication use also fluid contents and
contacts, pressure data and production performance data
• Prepare a good tabulation (database) of geologic data such as
depth of top & bottom of reservoir, net & gross thickness, fault’s
depth etc.
45. WELL #123 LATIHAN
WELL #456
B
OIL OWC
A
D OIL
C
46. WELL #123 LATIHAN
WELL #456
B
OIL OWC
A
D OIL
C
47. WELL #123 LATIHAN
WELL #456
B
OIL OWC
A
D OIL
C
48.
49. Tip for Reservoir Mapping
• Prepare a good base-map based on coordinates of
wells and seismic shot points (line & BM).
• Plot the data accurately then start contouring from
the highest positions for structure and refer to
seismic maps.
• Stucture contour should be stop whenever
cross/meet the fault plane. Consider the fault
throws and missing/repetition sections for the next
blocks contouring.
• For isopach maps initiate with facies map
construction then followed with isopach contouring.
• Understand the contouring principles such as no
crossing contour etc.
67. FAULT ANALYSIS
SEALING OR NON SEALING
• Can be based on :
– Log analysis
– Well test data
– Pressure build-up analysis
– Interference test
– Production data
– Using radioactive tracer
– Core & Rock Cutting
– Correlation & Sratigraphic analysis