Journal of Sciences Seismic Interpretation of … focal aim of the study is to map the structures in...

International Journal of Science and Technology Volume 2 No. 9, September, 2013

IJST © 2013– IJST Publications UK. All rights reserved. 648

Seismic Interpretation of Tomboy Field, Offshore Western Niger Delta,

Nigeria

S. O. Obaje Nigerian Geological Survey Agency, Kwara State Office, Federal Secretariat, Ilorin, Nigeria

ABSTRACT

The focal aim of the study is to map the structures in the study area using seismic interpretation methodology. Key stratal

terminations such as onlaps, toplaps and erosional unconformities (or truncations) were recognised. Nine surface

boundaries, namely: four maximum flooding surfaces and five sequence boundaries were detected as peaks and troughs of

the seismic onsets, respectively. The maximum flooding surfaces and the sequence boundaries depths were converted to

time in milliseconds using check shot data. The converted time represents two-way travel time. Accordingly, the wireline

logs were effectively tied to the seismic lines for better stratigraphic interpretation. Biostratigraphic data were used to date

the defined surface boundaries and their paleoenvironments of deposition. The structural style of the field is characterised

by two systems of antithetic and growth faults. On the seismic lines, shale structures were recognised as zones of chaotic or

transparent seismic reflections. The overall geometry of the reflectors is parallel or sub-parallel. On the seismic lines,

chaotic reflectors were identified to be associated with small-scale gravity faulting resulting in debris flow. The sandstone-

prone facies have greater seismic amplitude values than the shale-dominated units. The seismic expression of such

lithology change may have resulted from the juxtaposition of low amplitude and moderately continuous seismic facies

(shale-prone) on high-amplitude and variable continuity seismic facies (sand-prone). The identified structural and

stratigraphic traps, the reservoir blocks and the depositional environments are useful input to the petroleum system of the

area.

Keywords: Seismic Interpretation, Seismic Stratigraphy, Tomboy Field, Surface Boundary

1. INTRODUCTION

The area of study is located in the Tomboy field of the

offshore western Niger Delta area of Nigeria (Figs. 1 and

2). The Niger Delta is situated in the Gulf of Guinea on

the west coast of Central Africa. Niger Delta lies

between latitudes 4° and 6° N and longitudes 3° and 9° E

in the south-south geo-political region of Nigeria [16].

The Cenozoic Niger Delta is situated at the intersection

of the Benue Trough and the South Atlantic Ocean

where a triple junction developed during the separation

of South America and Africa in the Late Jurassic [27].

The main aim of this study is to map the structures in the

study area using seismic interpretation methodology.

Key stratal terminations such as onlaps, toplaps and

erosional unconformities (or truncations) were mapped

and integrated with log and biostratigraphic data to

establish the candidate surface boundaries in the study

area.

1.1 What is Seismic Stratigraphy?

Reflection seismology is compartmentalized into

acquisition, processing and interpretation. Seismic

stratigraphy deals with interpretation [2]. According to

McGraw-Hill Science and Technology Encyclopedia

[12], seismic stratigraphy is pronounced (′sīz·mik

strə′tig·rə·fē) and defined as a branch of stratigraphy in

which sediments and sedimentary rocks are interpreted

in a geometrical context from seismic reflectors. On the

other hand, it is defined as a technique used to determine

the nature of sedimentary rocks or their stratigraphic

interpretation by the analysis of seismic data [28], [24].

Primary seismic reflections are generated by physical

surfaces in the rocks, consisting mainly of stratal

surfaces and unconformities with velocities-density

contrasts of the bedding planes rather than

lithostratigraphic boundaries [24], [18], [10]. Andrew [2]

classified seismic stratigraphy into three principal

categories, namely: (i) seismic-sequence analysis, (ii)

seismic-facies analysis and (iii) reflection-character

analysis. Firstly, in seismic-sequence analysis, there is

need to separate out the time-depositional units based on

detecting the unconformities or changes in seismic

patterns as they are shown by angularity [12], [2].

Angularity below an unconformity may be produced by

erosion at an angle across the former bedding surfaces or

by toplap (offlap) and angularity above an unconformity

may be produced by onlap or downlap, the latter

distinction being based on geometry. The unconformities

are then followed along reflections from the points

where they cannot be so identified, advantage being

taken of the fact that the unconformity reflection is often

relatively strong. The procedure often followed is to

mark angularities in reflections by small arrows before

drawing in the boundaries. Secondly, Seismic-facies

units are three-dimensional and many of the conclusions

from them are based on their three-dimensional shape.

The appearance on seismic lines in the dip and strike

directions is often very different. For example, a fan-

shaped unit might show a progradational pattern in the

dip direction and discontinuous, overlapping arcuate

International Journal of Science and Technology (IJST) – Volume 2 No. 9, September, 2013


reflections in the strike direction. Thirdly, Reflection-

character analysis may be based on information from

boreholes which suggests that a particular interval may

change nearby in a manner which increases its likelihood

to contain hydrocarbon accumulations. Lateral changes

in the wave shape of individual reflection events may

suggest where the stratigraphic changes or hydrocarbon

accumulations may be located [12]. Finally, according

to Okosun [17], stratigraphy is the description and

classification of all rock bodies forming the earth’s crust

into distinctive and mappable units on the basis of their

inherent properties or attributes, distributions,

relationship and succession in space and time.

2. GEOLOGICAL SETTING

Three main formations have been recognised in the

subsurface of the Niger Delta [7], [21], [26], [4], [11],

[23]. These are the Akata, Agbada, and Benin

Formations. These formations were deposited in marine,

transitional and continental environments, respectively;

together they form a thick, overall progradational

passive-margin wedge [7].

The Akata Formation is Paleocene to Pliocene in age and

it is the basal unit composed mainly of marine shales

believed to be the main source rock within the basin. The

Agbada Formation is made up of alternating sandstone,

siltstone and shale sequences that constitute the

petroleum reservoirs of the basin. Agbada Formation is

Eocene to Quaternary in age (Figs. 3 and 4). On the

other hand, the Benin Formation is Oligocene to Recent

in age and it is mainly made up of non-marine fine to

coarse-grained sands with a few mudstone and shaly

intercalations [7].

Fig. 2. Seismic Survey Base Map of Study Area showing Locations of Five Wells

and the Seismic In-line and Cross-line Sections

Fig. 1. Location Map of the Study Area (Source: Tutle et al.[23])

STUDY AREA



Fig. 4. Southwest-northeast (B-B’) cross-section through the Niger Delta (modified from

Whiteman [27])

Fig. 3. Stratigraphic column showing the three formations of the Niger Delta (after Tuttle et al.[23];

modified from Doust and Omatsola [8])



3. MATERIALS AND METHODS

The materials for the study are seismic section, well

logs, base map and check shot data for five wells in the

study area. The five wells are named TMB-1, TMB-2,

TMB-4, TMB-5 and TMB-6 where TMB is an

abbreviation for Tomboy. The wells are drilled to the

depths of 3,782.57 m (TMB-1), 3,791.71 m (TMB-2),

3,489.96 m (TMB-4), 3,535.68 m (TMB-5) and 3,962.40

m (TMB-6). All the data were loaded on Landmark

Workstation. The database was created on the

Geographix Discovery R2007.1 platform (Windows)

version. The study was performed using SeisVision

3Dimensional (3D) seismic interpretation modules. The

parameters of the projection system used on the

Geographix Discovery are Coordinate System Type of

Transverse Mercator, Geographical Coordinate System

using Nigeria Minna (DMA REG MOL); Greenwich

Datum Prime Meridian and Minna Spheroid after Clarke

1880 Zone. The cross-line (strike) and the in-line (dip)

and the above mentioned data set were provided by

ChevronTexaco Nigeria Limited. The in-line (dip)

ranged from 5,800 to 6,200 and the cross-line (strike)

ranged from 1,480 to 1,700 covering a total area of 71.33

km2

and the line space of 2.51 km (Fig. 2). The 3D

seismic volume data were supplied in SEG-Y format,

while the well log data were given in LAS format.

Seismic and structural interpretation along the dip and

strike sections of the Tomboy field was undertaken in

this study with a view to identify and correlate the

surface boundaries along the seismic transect from one

well to another. The following method and workflow

plan was adopted: loading of seismic and well data,

review of seismic and log data after loading, integration

of biostratigraphic data and their calibration with seismic

data, identification of candidate sequence boundaries,

and the posting of the dominant faults on the transect.

The time-depth relationship was determined using the

check shot data available for TMB-1 well (Fig. 5). The

two-way time (TWT) is given in milliseconds (msec.) on

the x-axis, while the true vertical well depth is given on

the y-axis in feet (and the conversion value is 1 foot

equals 0.304804 metre). The depositional environments

were interpreted using the characteristic patterns and

curves of the gamma ray and resistivity logs in line with

the published charts of Busch [5] and Schlumberger [19]

(Figs. 6 and 7).

4. RESULTS AND DISCUSSION

4.1 Seismic to Well Calibration

The condensed sections are generally the most easily

recognised and dated regional correlatable surfaces. The

maximum flooding surface (MFS) is a clay-rich major

condensed interval formed by slow deposition of

sediments. This condensed section represents the deepest

water facies with a significant increase in fossils

diversity/abundance and abundance of authigenic

minerals (glauconite and phosphates) [25], [1]. The

gamma ray log provides a measure of sediment type, with

curve deflection to the right indicating increase in clay

content [3]. MFS’s can be interpreted from gamma-ray

log as “spikes” associated with uranium concentrations in

condensed sections.

Using biostratigraphic data, concentration and dilution

cycles are very important. In general terms, concentration

cycles represent zones where large numbers of

microfauna and flora are condensed over short intervals,

and they are often associated with maximum flooding

Fig. 5. The Plot of Check Shot Chart for TMB-1 Well (Conversion: 1 foot = 0.3048 metre)



surfaces (MFS’s). On the other hand, dilution cycles are

often associated with sequence boundaries [22].

The high resolution chronostratigraphic framework used

in the seismic interpretation is mostly MFS’s and SB’s

that have been assigned their absolute ages. Stacking

patterns seen on logs (and outcrops sections) are often

indicative of key stratigraphic surfaces. For example, the

change from retrogradational to progradational stacking

often is associated with a maximum flooding surface,

which can be checked in both seismic and

biostratigraphic data. Log motif interpretation of systems

tracts is particularly well defined [13]. Stacking patterns,

log curve shape, vertical trends in sand content, and

relationship to over- and underlying surfaces are keys to

identifying the systems tracts. However, integration with

seismic and other data is critical to validating these

interpretations [22]. Nine surface boundaries, namely:

four maximum flooding surfaces and five sequence

boundaries were defined as peaks and troughs of seismic

onsets, respectively (Table 1).

The maximum flooding surfaces (MFS’s) and the

sequence boundaries (SB’s) depths were converted to

time in milliseconds using the check shot data provided

by ChevronTexaco Nigeria Limited (Fig. 5).

Consequently, the wireline logs were effectively tied to

the seismic lines for better seismic stratigraphic

interpretation. The converted time representing the two

way travel time in relationship to the seismic stratigraphic

interpretation are given in Tables 3-7. Careful assessment

of the events recognised using the biostratigraphic age

dates of samples from the wells constrained by seismic

and wireline logs data indicated that 9.5 Ma, 10.4 Ma,

11.5 Ma and 12.8 Ma MFS’s constituted reliable

chronostratigraphic surfaces for the correlation of the

sequences within the wells in the study area. Key stratal

terminations such as onlaps, toplaps and erosional

unconformities (or truncations) were recognised. The

maximum flooding surfaces (MFS’s) coincided with the

seismic peaks, while the sequence boundaries (SB’s)

tallied with the seismic troughs (Table 1).

Table 1. Surface Boundaries (MFS’S & SB’S)

MFS (Ma) SB (Ma) NO. OF

WELLS

SEISMIC

ONSET

8.5 2 Trough

9.5 2 Peak

10.35 5 Trough

10.4 5 peak

10.6 5 Trough

11.5 5 Peak

12.1 5 trough

12.8 4 Peak

13.1 1 trough

4.2 Structural Interpretation

Structural interpretation was done on the Tomboy field

wells to map the structures, principally the fault patterns.

A geologic section based on the line drawn on the

seismic interpretation illustrates the structural style

observed in the study area (Figs. 8 - 11). Time horizons

constrained by well data and absolute ages indicated

Fig. 6. Gamma Ray and Resistivity Log Patterns

Indicative of Depositional Environments (Source:

Busch [5])

Fig. 7. Gamma Ray Log Stacking Patterns

Defining Deltaic Depositional Environments

(Source: Schlumberger [19])



Middle and Late Miocene. The structural style of the

field is characterised by two systems of antithetic and

growth faults. On the seismic lines, shale structures were

recognised as zones of chaotic or transparent seismic

reflections areas. The 3D seismic volume data is of good

quality, but below 3.5 seconds TWT the seismic lines are

very chaotic and of very poor quality and therefore, the

interpretation of such deeper horizons are uncertain.

The relative distance between the up-thrown sector and

the down-thrown sector of a fault is referred to as its

throw. The direction of throw is dominantly westward.

The faults (F1, F2, F3, F4 and F5) indicated that the faults

are down-thrown. The Faults (F6 and F7) basically are the

up-thrown faults. TMB-1, TMB-4 and TMB-6 wells are

situated in the down-thrown arms, having been affected

by F6 and F7 faults thus leading to the loss of some

horizon blocks from them. The F1 is observed to be

southwest trending fault, while F2 and F3 have western

trending pattern; F4 trends west to east direction, F5 has

nortwestern trend and F6 and F7 trend in northeastern

direction (Table 2). TMB-2 and TMB-5 wells are situated

in the up-thrown sector in relationship to fault (F2), while

TMB-6 well is located on the fault (F6). The wells were

correlated based on the relationships in the MFS’s and

the SB’s. Because some of the horizon blocks were

interpreted to have been faulted out, it may be inferred

that growth faults principally controlled the sequence

architecture of the study area (Figs. 8 - 11).

Table 2. Directions of Fault Patterns in the Tomboy Field

Table 3. Tomboy-1 Well Strike Section 1,620

DEPTH (M) TIME (SECONDS) SEISMIC

STATIGRAPHIC

INTERPRETATION

AGE

1,527.05 – 2,420.11 < 2.10 PGC

2,420.11 2.10 HST 8.5Ma SB

2,431.39 2.14 TST 9.5Ma MFS

2,471.32 2.20 TOP PGC

2,855.06 2.35 HST

2,882.80 2.40 TST 10.35Ma SB

2,908.71 2.45 TOP PGC 10.4Ma MFS

3,157.12 2.60 HST 10.6Ma SB

3,218.08 2.65 TST 11.5Ma MFS

3,386.94 2.72 HST 12.1Ma SB

3,404.92 2.74 TST 12.8Ma MFS

3,441.80 2.85 HST 13.1Ma SB

*PGC: Prograding Complex; TST: Transgressive System Tract; HST: High stand System Tract



STATIGRAPHIC

INTERPRETATION

AGE

1,527.05 – 2,268.93 < 2.0 *PGC

2,268.93 2.0 HST 8.5 Ma SB

2,431.39 2.1 TST 9.5 Ma MFS

2,639.57 2.25 HST 10.35 Ma SB

2,731.62 2.3 TST 10.4 Ma MFS

NAME OF FAULTS DIRECTION OF FAULT PATTERN

F1 Southwest trend

F2 and F3 Western trend

F4 West to East

F5 Northwest

F6 and F7 Northeast



3,046.17 2.5 HST 10.6 Ma SB

3,150.41 2.58 TST 11.5 Ma MFS

3,313.48 2.7 HST 12.1 Ma SB

3,446.37 2.8 TST 12.8 Ma MFS

Table 5. Tomboy-4 Well Dip Line 5,980


STATIGRAPHIC

INTERPRETATION

AGE

731.52 – 2,273.81 < 2.0 PGC

2,273.81 2.0 HST 10.35Ma SB

2,433.22 2.15 TST 10.4Ma MFS

2,728.27 2.35 TOP PGC

3,157.42 2.60 HST 10.6Ma SB

3,218.99 2.65 TST 11.5Ma MFS

3,404.62 2.75 HST 12.1Ma SB

Table 6. Tomboy-5 Well Dip Line 5,920


STATIGRAPHIC

INTERPRETATION

AGE

1,219.20 – 2,417.98 < 2.12 PGC

2,417.98 2.12 HST 10.35Ma SB

2,443.89 2.18 TST 10.4Ma MFS

2,581.35 2.25 TOP PGC

2,909.93 2.32 HST 10.6Ma SB

2,933.10 2.4 TST 11.5Ma MFS

2,957.47 2.50 TOP PGC

3,387.24 2.75 HST 12.1Ma SB

3,466.80 2.85 TST 12.8Ma MFS



STATIGRAPHIC

INTERPRETATION

AGE

1,222.25 – 2,948.33 < 2.52 PGC

2,948.33 2.52 HST 10.35Ma SB

3,258.01 2.60 TST 10.4Ma MFS

3,317.44 2.65 PGC

3,592.37 2.75 HST 10.6Ma SB

3,622.55 2.80 TST 11.5Ma MFS

12,615 2.85 HST 12.1Ma SB

3,907.23 3.0 TST 12.1Ma MFS

4.3 Unconformities

An unconformity is defined as the period of non-

deposition or erosional surfaces in a sedimentary

sequence [25], [6]. An unconformity can easily be

inferred from seismic data. The sequence boundary is

recognised by the erosional truncation of the underlying

strata and by the onlaps of overlying strata of the next

sequence [22] (Figs. 8 - 11). In the Tomboy field, five

unconformities were recognised in the wells. The

stratigraphic succession is generally represented by

nearly concordant, moderately bright amplitude

reflectors and only subtle erosional features representing

a limited incision were observed.

4.4 Flooding Surfaces

Maximum flooding surfaces correspond to the most

transgressive stratigraphic architecture and mark the

limits between genetically related sedimentary units.

According to Snedden and Sarg [22], regionally

continuous, parallel, uniformly high amplitude reflectors

in seismic data can be interpreted as candidate MFS’s. In

the study area, four maximum flooding surfaces were

identified and traced on the seismic sections. The



downlap surfaces were recognised to mark the maximum

flooding surfaces that change from retrogradational to

progradational parasequence sets [22].

4.4 Seismic Facies

Seismic facies are packages of reflectors with a set of

seismic characteristics differing from adjacent units (in

similarity to the definition of a formation), seismic facies

must be distinguishable from adjacent units and

mappable on earth's surface) [22]. Conventional and

qualitative seismic facies interpretation of stratigraphic

features such as turbiditic facies (downlap, mounds) and

lithology or fluid content were tentatively carried out. In

this study, the overall geometry of the reflectors is

parallel or sub-parallel. On the seismic lines, chaotic

reflectors were identified to be associated with small-

scale gravity faulting resulting in debris flow. The

sandstone-prone facies have greater seismic amplitude

values than the shale-dominated packages. The seismic

expression of such lithology change may have resulted

from the juxtaposition of low amplitude and moderately

continuous seismic facies (shale prone) on high-

amplitude and variable continuity seismic facies (sand-

prone).

Fig. 8. Interpreted seismic section showing transect

along in-line (dip) 5,980 section

Scale: vertical: 100 msec.; horizontal: 10 dip lines

Fig. 9. Collapsed crest structures and fault styles and

throw along in-line (dip) 5,980 section

Scale: vertical: 100 msec.; horizontal: 10 strike lines

Fig. 10. Interpreted seismic section showing cross-line

(strike) 1,600




Fig. 11. Structures with growth faults along cross-line

(strike) 1,600


4.6 Depositional System

From the seismic interpretation, it was detected that the

sequence architecture was strongly controlled by

extensional gravity-induced growth faulting. Though the

influence of the Niger Delta regional tectonism on the

local structural control was not differentiated; however,

it may be inferred that the following two factors may

have affected the depositional sequences: differential

subsidence, which in turn provided the variation in

accommodation and shales with local withdrawal which

may have provided areas of high subsidence.

The main traps are both structural and stratigraphic.

Structural traps include rollover folds, tilted fault blocks,

fault closure and horsts. Stratigraphic traps include pinch

outs, sand deposit in the down-thrown blocks and up-

thrown blocks, in-filled channels and debris flow

deposits. Stratigraphic facies changes and pinch-outs in

growth structure provide hydrocarbon traps; and may,

therefore, provide exploration and development

opportunities [20]. Biostratigraphic data [14] integrated

with gamma ray and resistivity log characteristic curves

were used to interpret the paleo-depositional

environments of the study area. The defined depositional

environments in stratigraphically ascending order are

Prodelta shales, channel sands, tidal/distributary channel

sands, barrier bar sands and upper shoreface deposits.

The sands are mostly interbeded by shales/mudstones

(Tables 8 - 12).

Table 8. The Environment of Deposition of Tomboy-1 Well interpreted using the Well Log Signatures

DEPTH (M) DEPOSITIONAL ENVIRONMENT

1,527.05 – 2,268.93 Upper shoreface

2,268.93 – 2,404.57 Inter-distributary channel overlain by shallow marine shales

2,404.57 – 2,868.47 Distributary channel sands overlain by shallow marine shales

2,868.47 – 3,150.41 Barrier bar sand deposits overlain by marginal marine shales


3,313.48 – 3,446.68 Channel sands with occasional shallow marine shales

3,446.68 – 3,779.52 Pro-delta shales





2,404.57 – 2,868.47 Distributary channel sands overlain by shallow marine shales

2,868.47 – 3,151.33 Barrier bar sand deposits overlain by marginal marine shales

3,151.33 – 3,313.48 Inter-distributary channel sand overlain by shallow marine shales

3,313.48 – 3,446.68 Channel sands with occasional shallow marine shales

3,446.68 – 3,791.71 Pro-delta shales



731.52 – 2,274.42 Upper shoreface

2,274.42 – 2,417.98 Lower shoreface

2,417.98 – 2,552.40 Tidal channel sands overlain by shallow marine shales

2,552.40 – 2,728.57 Inter-distributary channel sands

2,728.57 – 3,065.37 Distributary channel sands

3,065.37 – 3,270.20 Channel sands overlain by shallow marine shales

3,270.20 – 3,493.01 Pro-delta shales overlain by lower shoreface sands



Table 10. The Environment of Deposition of Tomboy- 5 Well interpreted using the Well Log Signatures



2,274.42 – 2,417.98 Lower shoreface

2,417.98 – 2,581.35 Tidal channel overlain by shallow marine shales

2,581.35 – 2,909.93 Distributary channel sands with shale/mudstone interbeds

2,909.93 – 3,270.20 Channel sands overlain by shallow marine shales

3,270.20 – 3,535.68 Marine shales overlain by tidal channel sands.

Table 12. The Environment of Deposition of Tomboy- 6 Well interpreted using the Well Log Signature



2,656.94 – 2,947.72 Channel sands overlain by shallow marine shales/siltstones

2,947.72 – 3,134.26 Tidal channel sands with occasional shales interbeds

3,134.26 – 3,317.44 Distributary channel sands with shale/mudstone interbeds

3,317.44 – 3,592.68 Distributary channel sands

3,592.68 – 3,962.40 Lower shoreface overlain by prodelta muds/shales

4.7 Lithostratigraphy

The logs analytical data indicated the presence of two

lithostratigraphic units in the Tomboy field, viz: the

paralic Agbada and the continental Benin Formations,

respectively, that are recognised in the Niger Delta area

[21], [27]. The Agbada Formation, as shown in the wells,

is typically a sequence of sandstones alternating with

shales/mudstones, with sands predominating up-section.

On the other hand, the Benin Formation is dominantly

made up of non-marine (fluviatile) fine to coarse-grained

sands with a few mudstone and shaly intercalations [7].

The thickness of the Agbada and Benin Formations

varied widely in the five wells studied. The Agbada

Formation is predominantly shale/mudstone sequence

alternating with variably, thickly bedded channel

sandstones with coarsening upward and occasionally

finning upward log signatures. The two recognised

lithostratigraphic units and their thicknesses in the study

area are shown in Table 13.

4.8 Chronostratigraphy

The ages of the five wells in the XY-1 Field range

between Middle and Late Miocene based on the high

resolution biostratigraphic data [14]. All the MFS’s and

SB’s fell within the Middle and Late Miocene interval

and the five wells were adequately correlated (Table 14;

Fig. 12).

Table 13. Lithostratigraphic Data of Tomboy Field (Source: Obaje and Okosun [15])

FORMATION TMB-1 DEPTH (M) TMB-2 DEPTH (M) TMB-4 DEPTH (M) TMB-5 DEPTH (M) TMB-6 DEPTH (M)

BENIN 1,527.05-2,268.93 1,527.05-2,282.95 731.52-2,273.81 1,219.20-2,417.98 1,222.25-2,948.33

AGBADA 2,268.93-3,779.52 2,282.95-3,791.71 2,273.81-3,489.96 2,417.98-3,535.68 2,948.33-3,962.40

Table 14. Chronostratigraphic Data of Tomboy Field S/N WELL NAME DEPTH (M) AGE

1. TMB-1 1,527.05-2,721.86 Late Miocene

2,721.86-3,791.71 Middle Miocene

2. TMB-2 1,527.05-3,142.49 Late Miocene


3. TMB-4 731.52-2,433.52 Late Miocene


4. TMB-5 1,219.20-2,933.10 Late Miocene


5. TMB-6 1,222.25-3,258.01 Late Miocene


Table 15. Chronostratigraphic Horizons of Tomboy Field

MFS

(Ma)

SB

(Ma)

WELL NAME AND DEPTHS (M)

TMB-1 TMB-2 TMB-4 TMB- 5 TMB- 6

8.5 2,268.93 2,420.11 - - -

9.5 2,431.39 2,431.39 - - -

10.35 2,639.57 2,855.06 2,273.81 2,417.98 2,948.33

10.4 2,731.31 2,882.80 2,433.22 2,443.89 3,258.01

10.6 3,046.17 3,157.12 3,157.42 2,909.93 3,592.37

11.5 3,150.41 3,218.08 3,218.99 2,933.09 3,622.55

12.1 3,313.48 3,386.94 3,404.62 3,387.24 3,845.05

12.8 3,446.37 3,404.92 - 3,466.80 3,907.23

13.1 - 3,441.80 - - -



5. CONCLUSION AND RECOMMENDATION

The direction of throw of the faults is dominantly

westward. The faults (F1, F2, F3, F4 and F5) indicated that

the faults are down-thrown. The Faults (F6 and F7)

basically are the up-thrown faults. TMB-1, TMB-4 and

TMB-6 wells are situated in the down-thrown arms,

having been affected by F6 and F7 faults thus leading to

the loss of some horizon blocks from them. The F1 is

observed to be southwest trending fault, while F2 and F3

have western trending pattern; F4 trends in west to east

direction; F5 has nortwestern trend, while F6 and F7 trend

in northeastern direction. TMB-2 and TMB-5 wells are

situated in the up-thrown sector in relationship to fault

(F2), while TMB-6 well is located on the fault (F6). The

wells were correlated based on the relationships in the

MFS’s and the SB’s. Because some of the horizon blocks

were interpreted to have been faulted out; it may be

inferred that growth faults principally controlled the

sequence architecture in the study area. The main traps

are both structural and stratigraphic. Structural traps

include rollover folds, tilted fault blocks, fault closure

and horsts. Stratigraphic traps include pinch outs, sand

deposit in the fault down-thrown blocks and up-thrown

blocks, in-filled channels, debris flow deposits and

shale/clays infilling and sealing of the fault planes.

Stratigraphic facies changes and pinch-outs in growth

structure provide hydrocarbon traps; and may, therefore,

provide exploration and development opportunities in the

Tomboy field and other areas of the Niger Delta. In this

study, the overall geometry of the reflectors is parallel or

sub-parallel. On the seismic lines, chaotic reflectors were

identified to be associated with small-scale gravity

faulting resulting in debris flow. The sandstone-prone

facies have greater seismic amplitude values than the

shale-dominated packages. The seismic expression of

such lithology change may have resulted from the

juxtaposition of low amplitude and moderately

continuous seismic facies (shale prone) on high-

amplitude and variable continuity seismic facies (sand-

prone). Five unconformities were recognised in the wells

of the study area. The stratigraphic succession is

generally represented by nearly concordant, moderately

bright amplitude reflectors and only subtle erosional

features representing a limited incision were observed.

On the other hand, downlap surfaces were traced on the

seismic sections to mark four recognised candidate

maximum flooding surfaces which were established using

wireline logs and biostratigraphic data. Using integrated

data set from wireline logs and biostratigraphy, five

depositional environments recognised in stratigraphically

ascending order are prodelta shales, channel sands, tidal

and distributary channels sands, barrier sands and

shoreface deposits.

It is recommended that structural map of the sub-surface

horizons should be produced for further study of the

area.

Depth

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

Gamma Log(API)0 150

Lit

ho

log

y

Deep Laterolog(ohm m/m)0.2 2000

Lit

ho

stratig

rap

hy

5010

Be

nin

Fo

rma

tio

n

7444

12440

Ag

ba

da

Fo

rma

tio

nF

orm

atio

n

Seq

uen

ce

5010

PG

C

7444

HS

T

7978

TS

T

8661

HS

T

8962

TS

T

9994

HS

T

10336

TS

T

10871

HS

T

11308

12440

TS

T

Div

ersity: M

icro

pa

lae

on

tolo

gy

60

In-S

itu occurrences

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

4

252

4

1

11

5

6

7

3

4

201

2

4

3

5

28

2525

32

29

3

9

2

32

3

1

8

1

10

5

9

16

13

5

8

3

2

10

514

10

10

5

1

2

249

1

2

1

4

4

4

3

3

186

7

10

16

6

9

10

3

26

8

8

13

19

18

11

10

9

11

97

423

12

8

2

1

8

5

4

4

2

Micro.

To

tal co

un

t: M

icro

pa

lae

on

tolo

gy

80

In-S

itu occurrences

8

6

5

21

41

5

12

10

18

13

17

17

44

12

46

17

7

23

27

7

5

12

5

4

35

5

28

16

130

14

3

3

1

1

2

4

1012

12

3

30

13

11

7

3

5

1221

3

8

3

7

64

150105

117

116

3

13

2

137

4

1

11

1

18

7

19

32

28

7

13

3

8

13

524

12

32

5

1

2

14112

1

3

2

7

4

4

6

6

458

18

13

24

9

15

16

3

168

11

9

25

56

43

21

14

11

18

23104

6121

16

2

1

15

10

4

4

2

Micro. *1

*2

No

n M

arin

e

Div

ersity: N

an

no

pa

lae

on

tolo

gy

15

In-S

itu occurrences

3

21

111

4

54

86

61

82

1

3

1

2

1

11

9

1

25

1

8

1

1

1

2

22

41

1

1

5

1

3

4

1

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

10

In-S

itu occurrences

5

21

111

5

65

98

61

112

1

4

1

2

1

11

24

1

27

1

11

1

3

1

2

22

91

1

1

7

1

3

9

1

Nanno.

Events

7444' 8.5Ma SB

7977' 9.5Ma MFS

8660' 10.35Ma SB

8961' 10.4Ma MFS

9994' 10.6Ma SB

10336' 11.5Ma MFS

10871' 12.1Ma SB

11307' 12.8Ma MFS

Depth

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

Gamma Log(API)0 150

Lit

ho

log

y

Deep Induction(ohm m/m)0.2 2000

Lit

ho

stratig

rap

hy

5010

Be

nin

Fo

rma

tio

n

7940

12440

Ag

ba

da

Fo

rma

tio

nF

orm

atio

n

Seq

uen

ce

5010

PG

C

HST7978

TS

T

8108

PG

C

HST

TST9543

PG

C

10358

HS

T

10559

TS

T

HST11171

TS

T

11293

12440

HS

T

Div

ersity: M

icro

pa

lae

on

tolo

gy

20

In-S

itu occurrences

4

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

4

2

4

1

11

5

6

7

3

2912

1

2

4

3

5

14

6

6

11

3

9

2

3

1

8

1

2510

526

9

16

13

5

8

3

2

10

5

10

10

5

1

2

914

1

2

1

164

4

4

3

3

6

7

10

1614

626

9

10

253

8

8

13

19

18

11

10

9

11

9

8

11

6

6

6

3

6

5

Micro.

To

tal co

un

t: M

icro

pa

lae

on

tolo

gy

40

In-S

itu occurrences

4

8

6

5

21

23

5

12

10

18

13

17

17

21

12

27

17

7

23

27

7

5

12

5

4

24

5

28

16

37

14

3

3

1

1

2

4

2

12

3

30

13

11

7

3

7344

1

3

8

3

7

21

16

16

39

3

13

2

4

1

11

1

6518

7130

19

32

28

7

13

3

8

13

5

12

32

5

1

2

1224

1

3

2

327

4

4

6

6

8

18

13

2417

997

15

16

563

11

9

25

56

43

21

14

11

18

23

8

17

7

11

11

5

10

9

Micro. Palaeoenvironment

Default

No

n M

arin

e

Tra

ns

itio

na

l

Inn

er

Ne

riti

c

Mid

dle

Ne

ritic

Div

ersity: N

an

no

pa

lae

on

tolo

gy

8

In-S

itu occurrences

3

21

111

4

74

89

61

82

1

3

12

1

11

9

1

25

1

1

1

1

2

8

22

41

1

1

1

5

3

4

1

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

15

In-S

itu occurrences

5

21

111

10

127

1924

91

112

1

4

12

1

11

43

1

27

1

1

3

1

2

21

22

91

1

1

1

7

3

18

1

Nanno.

Events

7940' 8.5Ma SB7977' 9.5Ma MFS

9367' 10.35Ma SB

9458' 10.4Ma MFS

10358' 10.6Ma SB

10558' 11.5Ma MFS

11112' 12.1Ma SB

11171' 12.8Ma MFS

11292' 13.1Ma SB

Depth

2500'

2750'

3000'

3250'

3500'

3750'

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

Gamma Log(API)0 150

Lit

ho

log

y


Lit

ho

stratig

rap

hy

2400

Be

nin

Fo

rma

tio

n

7461

11460

Ag

ba

da

Fo

rma

tio

nF

orm

atio

n

Seq

uen

ce

2400

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

7461

HS

T

7984

TS

T

8951

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

10359

HS

T

10562

TS

T

HST11170

11460

TS

T

Div

ersity: M

icro

pa

lae

on

tolo

gy

25

In-S

itu occurrences

12

8

10

5

7

4

10

8

9

9

7

5

7

4

5

6

4

5

12

11

8

9

7

5

9

9

4

14

16

13

8

7

3

3

2

5

3

1

9

10

13

10

2

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

425

17

4

1

11

5

6

7

3

420

121

2

4

3

5

28

2525

32

29

3

9

232

3

1

8

1

10

5

9

16

13

5

8

3

2

10

514

10

10

5

1

224

925

1

2

1

264

4

4

3

318

6

7

10

16

614

9

10

326

8

8

Micro.

To

tal co

un

t: M

icro

pa

lae

on

tolo

gy

20

In-S

itu occurrences

21

16

18

6

15

5

18

16

17

17

15

6

10

8

9

11

4

9

21

19

16

13

15

9

17

17

4

24

33

36

8

10

3

4

2

6

3

1

14

19

24

17

3

8

6

5

21

41

5

12

10

18

13

17

17

44

12

46

17

7

23

27

7

5

12

5

4

35

5

28

16

130

14

3

3

1

1

2

410135

12

3

30

13

11

7

3

512244

1

3

8

3

7

64

150105

117

116

3

13

2137

4

1

11

1

18

7

19

32

28

7

13

3

8

13

524

12

32

5

1

2141

1265

1

3

2130

7

4

4

6

645

8

18

13

24

924

15

16

3168

11

9


Default

No

n M

arin

e

Tra

ns

itio

na

l

Inn

er

Ne

riti

c

Mid

dle

Ne

ritic

Div

ersity: N

an

no

pa

lae

on

tolo

gy

15

In-S

itu occurrences

1

1

3

21

111

4

54

86

61

82

1

3

1

2

1

11

99

1

25

1

8

1

1

1

2

22

41

1

1

5

1

8

3

4

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

20

In-S

itu occurrences

3

1

5

21

1

1

1

5

65

98

61

1121

4

1

2

1

1

1

2438

1

27

1

11

1

3

1

2

22

91

1

1

7

1

11

3

9

Nanno.

Events

7460' 10.35Ma SB

7983' 10.4Ma MFS

10359' 10.6Ma SB

10561' 11.5Ma MFS

11170' 12.1Ma SB

Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

Gamma Log(API)0 150

Lit

ho

log

y


Lit

ho

stratig

rap

hy

4000

BE

NIN

FO

RM

AT

ION

7462

11600

AG

BA

DA

FO

RM

AT

ION

Fo

rm

atio

n

Seq

uen

ce

4000

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

HST8018

TS

T

8469

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

HST

TST9703

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

11114

HS

T

11375

11600

TS

T

To

tal co

un

t: M

icro

pa

lae

on

tolo

gy

40

In-S

itu occurrences

24

33

36

8

10

3

4

2

6

3

1

14

19

24

17

3

8

6

5

21

41

5

12

10

18

13

17

17

44

12

46

17

7

23

27

7

5

12

5

4

35

5

28

16

130

14

3

3

1

1

2

4101

2

12

3

30

13

11

7

310

5122

1

44

3

8

3

7

64

150105

117

116

3

13

2

137

4

1

11

1

18

7

1922

3228

327

13

3

8

13

524

12

32

5

1

2

14112

1

3

2

7

4

4

6

645

8

18

13

24

159

15

16

3168

1117

9

25

56

43

Micro.

Div

ersity: M

icro

pa

lae

on

tolo

gy

15

In-S

itu occurrences

14

16

13

8

7

3

3

2

5

3

1

9

10

13

10

2

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

425

2

4

1

11

5

6

7

39

420

112

2

4

3

5

28

2525

32

29

3

9

232

3

1

8

1

10

5

913

1613

165

8

3

2

10

514

10

10

5

1

2

249

1

2

1

4

4

4

3

318

6

7

10

16

136

9

10

326

814

8

13

19

18


Default

No

n M

arin

e

Tra

ns

itio

na

l

Inn

er

Ne

riti

c

Mid

dle

Ne

ritic

Div

ersity: N

an

no

pa

lae

on

tolo

gy

20

In-S

itu occurrences

1

1

3

21

1

1

1

4

54

86

61

821

3

1

2

1

1

1

9

9

1

25

1

8

1

1

1

2

22

41

81

1

5

1

3

4

5

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

25

In-S

itu occurrences

3

1

5

21

1

1

1

5

65

98

61

1121

4

1

2

1

1

1

24

50

1

27

1

11

1

3

1

2

22

91

321

1

7

1

3

9

7

Nanno.

Events

7933' 10.35 Ma SB

8018' 10.4 Ma MFS

9547' 10.6Ma SB

9623' 11.5Ma MFS

11113' 12.1Ma SB

11374' 12.8Ma MFS

Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

12500'

12750'

13000'

Gamma Log(API)0 150

Lit

ho

log

y

Deep Induction(ohm m/m)0.2 2000

Lit

ho

stratig

rap

hy

4000

Be

nin

Fo

rma

tio

n

7560

13000

Ag

ba

da

Fo

rma

tio

nF

orm

atio

n

Seq

uen

ce

4000

Lo

wsta

nd

Pro

gra

din

g C

om

ple

x

8717

HS

T

10689

TS

T

10884

Lo

wsta

nd

Pro

gra

din

g C

om

ple

x

HST11885

TS

T

12615

HS

T

12819

13000

TS

T

Samples

Barren

4040

4100

4160

4220

4280

4340

4400

4460

4520

4580

4640

4700

4760

4820

4880

4940

500050105060

5120

5180

5240

5300

5360

5420

5480

5540

5600

5660

5720

5780

5840

5900

5960

6020

6080

6140

6200

6260

6320

6380

6440

6500

6560

6680

6740

6800

6860

6920

6980

7040

7100

7160

7220

7280

7340

740074447460

7520

7580

7640

7700

7760

7820

7880

794079788000

8060

8120

8180

8240

8420

8480

8540

8600

86608661

8720

8780

8840

8900

89608962

9020

9080

9140

9260

9320

9380

9440

9500

9560

9620

96739680

9740

9800

9860

9920

9980999410040

10100

10160

10220

10280

1033610340

10400

10460

10520

10580

106401068910700

10760

108201087110880

10940

11000

11060

11120

11180

11240

113001130811360

11420

11480

11540

11600

11660

11720

1178011787118401188511900

11960

12020

12080

12140

12200

12260

12320

12380

12440

12500

12560

1261512620

12680

12740

128001281912860

12920

Div

ersity: M

icro

pa

lae

on

tolo

gy

20

In-S

itu occurrences

14

16

13

8

7

3

3

2

5

3

1

9

10

13

10

2

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

425

2

4

1

11

5

6

7

3

420

1

2

4

3

5

28

2525

32

29

3

9

232

3

1

8

1

10

5

9

16

13

255

8

3

2

10

514

10

10

5

1

2

249

1

2

1

4

412

4

3

318

6

7

10

16

6

9

10

326

8

8

13

19

18

11

10

920

1126

9

23

7

8

7

2

3

8

6

6

7

2

57

8

6

316

4

8

Micro.T

ota

l co

un

t: M

icro

pa

lae

on

tolo

gy

50

In-S

itu occurrences

24

33

36

8

10

3

4

2

6

3

1

14

19

24

17

3

8

6

5

21

41

5

12

10

18

13

17

17

44

12

46

17

7

23

27

7

5

12

5

4

35

5

28

16

130

14

3

3

1

1

2

4101

2

12

3

30

13

11

7

3

5122

1

3

8

3

7

64

150105

117

116

3

13

2

137

4

1

11

1

18

7

19

32

28

687

13

3

8

13

524

12

32

5

1

2

14112

1

3

2

7

444

4

6

645

8

18

13

24

9

15

16

3168

11

9

25

56

43

21

14

1140

1898

23

61

15

16

15

2

3

16

13

7

8

2

815

16

11

332

4

16


Default

No

n M

arin

e

Tra

ns

itio

na

l

Inn

er

Ne

riti

c

Mid

dle

Ne

ritic

Samples

Barren

40104040407041004130416041904220425042804310434043704400443044604490452045504580461046404670470047304760479048204850488049104940497050005030506050905120515051805210524052705300533053605390542054505480551055405570560056305660569057205750578058105840587059005930596059906020605060806110614061706200623062606320635063806410644064706500653065606590662066506680671067406770680068306860689069206950698070407100713071607190722072507310734073707400743074447490752075507580761076407670770077307760779078207850788079107940797079788000803080608090812081508180821082408270830083308360839084208450848085108540857086308660866186908720875087808810884088708900893089608962899090209050908091109140917092009230926092909320938094109440947095009530956095909620965096809710974097709800983098609890992099509980100101004010070101001013010160101901022010250102801031010336103401037010400104301046010490105201055010580106101064010670106891070010730107601082010850108801091010940109701100011030110601109011120111501118011210112401127011300113081133011360113901142011450114801151011540115701160011630116601169011720117501178011810118401187011885119001193011960

12819

Div

ersity: N

an

no

pa

lae

on

tolo

gy

10

In-S

itu occurrences

1

1

3

21

111

4

54

86

61

82

1

3

1

2

1

11

9

1

25

1

8

1

1

1

2

22

41

1

1

5

1

9

3

4

1

8

5

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

12

In-S

itu occurrences

3

1

5

21

111

5

65

98

61

112

1

4

1

2

1

11

24

1

27

1

11

1

3

1

2

22

91

1

1

7

1

34

3

9

1

11

18

Nanno.

Events

9673' 10.35 Ma SB

10689' 10.4 Ma MFS

11786' 10.6Ma SB

11885' 11.5Ma MFS

12615' 12.1Ma SB

12819' 12.8Ma MFS

Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

12500'

12750'

13000'

Well Name : TOMBOY-1Operator : TOMBOY

Well Code: TOMBOY-1

Lat/Long : 52°31' 25.01"N 2° 2' 3.00"E

Interval Various

Scale Various

Chart date: 28 January 2003 Project

Chart

: BIOSTRAT

: TOMBOY-CORRELATION

TOMBOY-1 TOMBOY-2 TOMBOY-4 TOMBOY-5 TOMBOY-6

Base Lithology

clay

shale/mudstone

silty mudstone

sandy mudstone

siltstone

argillaceous siltstone

sandy siltstone

sandstone (fine - medium)

sandstone (coarse)

argillaceous sandstone

mixed sandstone (70% coarse)

Text Keys*1 Palaeoenvironment

*2 Default

Tomboy-1 Tomboy-2 Tomboy-4 Tomboy-5 Tomboy-6

Fig. 12. Correlation Chart of Five Wells in Tomboy Field (Source: Obaje [14])



REFERENCES

[1] Adegoke, O.S. (2002): High resolution

biostratigraphy, sequence stratigraphy, 3-D

modeling: indispensable tools for E & P

activities in the new millennium. NAPE

Bulletin vol. 16, no. 1, pp. 46 – 65.

[2] Andrew, T., 2013. Seismic stratigraphy,

Published Lecture Notes, Department of Earth

Sciences, National Central Univ., Taiwan, 48

pp. Available at

http://140.115.21.141/download/courses/sequen

ce_strat/10_seismic_stratigraphy.pdf

[3] Asquith, G. B. and Gibson, C. R. (1999): Basic

well log analysis for geologists. AAPG Methods

in Exploration Series no. 3, 218 pp.

[4] Avbovbo, A.A., 1978. Tertiary lithostratigraphy

of Niger Delta, AAPG Geol. Notes, pp. 296-

300.

[5] Busch, D.A., 1975. Influence of growth faulting

on sedimentation and prospect evaluation. Am.

Assoc. Petrol. Geol. Bulletin, v. 59, No. 3, p.

414–419.

[6] Emery, D. and Myers, K. (1997):

Sequence stratigraphy. Blackwell

Science, Australia, 297 pp.

[7] Esan, A.O., 2002. High resolution sequence

stratigraphic and reservoir characterization

studies of D-07, D-08 and E-01 sands, Block 2

Meren Field, Offshore, Niger Delta,’’ Publ.

M.S. Geology Thesis, Texas A & M University,

Texas, USA, 115 pp.

[8] Doust, H. and Omatsola, E., 1990. Niger Delta.

In Edwards, J.D. and Santogrossi, P.A. (Eds.),

Divergent/Passive Margin Basins, American

Association of Petroleum Geologists Memoir

48, pp. 201-239.

[9] Frankl, E.J. and Cordy, E.A., 1967. The Niger

Delta Oil Province Recent Development

Onshore and Offshore, 7th

World Petroleum

Congress Proceedings, Mexico City, IB, pp.

195-209.

[10] Juhlin C., 2008. Seismic Stratigraphy

Interpretation Applied to Sequence

Stratigraphy. Published Lecture Notes of

Department of Earth Sciences, Uppsala

University, Sweden, 40 pp. Available at

http://www.geofys.uu.se/cj/seis_strat/notes/seis

_strat_interp_notes_web.pdf

[11] Knox, G.J. and Omatsola, E.M., 1989.

Development of the Cenozoic Niger delta in

Terms of the “Escalator Regression” Model and

Impact on Hydrocarbon Distribution. In. van

der Linden, W.J.M. et al. (Eds.), Proceedings,

KNGMG Symposium on Coastal Lowlands,

Geology, Geotechnology, Dordrecht, Kluwer

Academic Publishers, pp. 181-202.

[12] McGraw-Hill Science and Technology

Encyclopedia (2013): Seismic stratigraphy,

AnswersCorporation. Available at

http://www.answers.com/topic/seismic-

stratigraphy

[13] Mitchum, R. M., Jr., Sangree, J. B., Vail, P. R.

and Wornardt, W. W. (1993): Recognizing

sequences and systems tracts from well logs,

seismic data, and biostratigraphy: examples

from the Late Cenozoic of the Gulf of Mexico,

in: Weimer, P. and Posamentier, H. (eds.),

Siliciclastic sequence stratigraphy, AAPG

Memoir no. 58, Tulsa, USA, pp. 163–197.

[14] Obaje, S.O., 2011. Sequence Stratigraphy and

Biostratigraphy of XY-1 (Tomboy) Field,

Offshore Western Niger Delta, Nigeria.

Unpublished PhD Geology dissertation, Federal

University of Technology, Minna, Nigeria,

254pp.

[15] Obaje, S.O. and Okosun, E.A., 2013. Planktic

Foraminiferal Biozonation and Correlation of

XY-1 Field, Offshore Western Niger Delta,

Nigeria. Int. J. Sci. Techn., v. 3 no. 3, pp. 160-

167.

[16] Ojo, E.A., Fadiya, L.S. and Ehinola, O.A.,

2009. Biozonation and correlation of BDX-1

and BDX-2 wells of deep offshore Niger Delta

using calcareous nannofossils, Search and

Discovery Article (AAPG) no. 50194, 8 pp.

[17] Okosun, E.A., 2013. The Traverses of a

stratigrapher in Nigerian sedimentary basins.

Published Inaugural Lecture Series 26, Federal

University of Technology, Minna, Nigeria, 64

pp.

[18] Ramsayer, G.R., 1979, Seismic Stratigraphy, A

Fundamental Exploration Tool, Publisher

Offshore Technology Conference, USA, 10 pp.

Available at

http://www.onepetro.org/mslib/servlet/onepetro

preview?id=OTC-3568-MS

[19] Schlumberger, 1985. Log Interpretation

Principle and Applications, Schlumberger

Educational Services, order no. SMP-7017,

Houston, USA.

[20] Shaw, J.H., Nova, E. and Connors, C.D., 2004.

Structural controls on growth stratigraphy in

contractional fault-related folds, in: McClay,

K.R. (ed.), Thrust tectonics and hydrocarbon

systems. AAPG Memoir 82, pp. 400– 412.



[21] Short, K.C. and Stäuble, A.J., 1967. Outline of

Geology of Niger Delta,’’ American

Association of Petroleum Geologists Bulletin 5,

vol. 51, pp. 761-779.

[22] Snedden, J. W. and Sarg, J. F.N. (2008):

Seismic stratigraphy: A primer on methodology,

Search and Discovey Article no. 40270, 29 pp.

Available at

http://www.searchanddiscovery.net/documents/

2008/08004snedden/index.htm

[23] Tuttle, L.W.M., Charpentier, R.R. and

Brownfield, E.M., 1999. The Niger Delta

Petroleum System: Niger Delta Province,

Nigeria Cameroon, and Equatorial Guinea,

Africa, U.S. Geological Survey Open-File

Report 99-50-H, Denver, Colorado, 70 pp.

[24] Vail, S.S., 2013. Seismic stratigraphy.

Published Lecture Note, Department of

Geology, University of Puerto Rico, Mayaguez

(UPRM). Available at

http://geology.uprm.edu/Classes/GEOL6992/SS

VailRevol.pdf

[25] Van Wagoner, J.C., Mitchum, R.M., Campion,

K.M. and Rahmanian, V.D., 1990. Siliciclastic

sequence stratigraphy in well logs, cores and

outcrops: concepts of high-resolution

correlation of of time and facies: Am. Assoc.

Petrol. Geol., Methods in Exploration no. 7,

pp. 1–55.

[26] Weber, K.J. and Daukoru, E., 1975. Petroleum

Geology of the Niger Delta, Proceedings of the

9th

World Petroleum Congress, Tokyo, vol.2,

pp. 202-22.

[27] Whiteman, A., 1982. Nigeria- Its Petroleum

Geology, Resources and Potential, London,

Graham and Trotman, p. 394.

[28] Wiktionary, 2013. Available at

http://en.wiktionary.org/wiki/seismic_stratigrap

hy

Date post:	30-May-2018
Category:	Documents
Upload:	lamkhuong
View:	213 times
Download:	0 times

Journal of Sciences Seismic Interpretation of … focal aim of the study is to map the structures in...

Documents