Malaysian Journal of Geosciences (MJG)

DELINEATION OF SUBSURFACE STRUCTURES IN TOJA FIELD IN THE NIGER DELTA USING WELL-LOGS AND SEISMIC DATA

mjg.02.2019.43.51

ABSTRACT

DELINEATION OF SUBSURFACE STRUCTURES IN TOJA FIELD IN THE NIGER DELTA USING WELL-LOGS AND SEISMIC DATA

Journal: Malaysian Journal of Geosciences (MJG)
Author: Obioma Umunna, Etim D. Uko, Idara O. Akpabio

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2019.43.51

The subsurface structures delineation of TOJA Field southwest Niger Delta using well-log and seismic data is here presented. The reflectivity seismic amplitude and acoustic impedance, spectra decomposition volume derivatives were used for reservoir delineation. Seismic data and well logs have been integrated through seismic inversion as part of the techniques deployed in the delineation of subsurface structures in the Niger Delta basin. Well logs were tied to seismic data using four wells from four fields in the Niger Delta. Reflectivity seismic data was inverted to generate a 3D distribution of P-impedance in the fields of interest. Fluid and lithology sensitivity analysis including cross-plotting, forward seismic modelling and Gassmann fluid substitution was performed to delineate various subsurface structures. The TOJA prospect is a footwall-closure located behind the main bounding fault, north of the TOJA Field. The Field’s structure is a fault-dependent footwall closure with a dip component in the shallow levels. The structure is bounded by three faults; a large east-west fault forms the boundary between the TOJA Field to the South and the TOJA North Field. This fault is relayed by a minor fault that delimits the south-western end of the accumulation. A northeast-southwest bounding fault separates the TOJA structure from the SATRA accumulations to the east and has a throw of between 200 and 400 ft. The results of this study can lead to a more cost-effective method for defining the Field Development Plan (FDP), through the use of seismically constrained reservoir information that would provide better well placement to achieve improved production.
Pages 43-51
Year 2019
Issue 2
Volume 3

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mjg.02.2019.23.32

ABSTRACT

AN INTEGRATED APPROACH TO GROUNDWATER QUALITY ASSESSMENT IN DETERMINING FACTORS THAT INFLUENCE THE GEOCHEMISTRY AND ORIGIN OF SANDSTONE AQUIFER SOUTHERN NIGER DELTA REGION OF NIGERIA

Journal: Malaysian Journal of Geosciences (MJG)
Author: M. O. Eyankware, O. O. Omo-Irabor

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2019.23.32

Rapid industrialization and oil exploration activities is believed to have influence on groundwater quality globally, and Niger Delta Region of Nigeria is no exception. Hence, this research is conducted to evaluate factors that influence groundwater origin and its geochemistry. For the purpose of this study, 20 groundwater samples were collected (4 from borehole and 16 from hand-dug wells). The parameters used in the assessment include physical parameters; pH, total dissolved solid and electrical conductivity and chemical parameters such as; major cations and anions. From the findings it was observed that pH values fell within the slightly acidic range with the exception of sample location HG/08 with value of 7.01 which can consider to be neutral. The dominant factors that influence groundwater origin and geochemistry within the study area are mainly precipitation and weathering. From Gibb’s plot ninety percent (90 %) of groundwater chemistry is influenced by precipitation. While, Soltan classification showed that 98 % of groundwater belongs to (Na+ – SO42¯), hence it can be classified as deep meteoric (precipitation influence), while the remaining (2%) is of (Na+ – HCO3¯) its classified as shallow meteoric type. Lastly from relationship between Cl¯/HCO3¯ groundwater were slightly moderately affected by saline water intrusion.
Pages 23-32
Year 2019
Issue 2
Volume 3

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mjg.02.2019.33.42

ABSTRACT

PERMEABILITY-POROSITY TRENDS IN CAWC RESERVOIR SANDS IN THE NIGER DELTA NIGERIA, USING WELL-LOG DATA

Journal: Malaysian Journal of Geosciences (MJG)
Author: Chinedu S. Orji, Etim D. Uko, Iyeneomie Tamunobereton-ari

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2019.33.42

Reservoir characteristics analysis in the onshore Cawthorne Channel (CAWC) oil field, Niger Delta is here presented. The aim of the research was to assess reservoir properties and their relationships. A suite of geophysical logs comprising gamma ray, resistivity, neutron and density logs from eight wells were used in the analysis. Three reservoirs sands were delineated and linked across all eight wells. The litho-stratigraphy correlation section revealed that each of the sand units spreads over the field are differs in thickness with some units occurring at greater depth than their adjacent unit, that is possibly an evidence of faulting. The results show volume of shale values range from 11% to 17% indicating that the fraction of shale in the reservoirs is quite low. The total porosity of the reservoirs ranges from 0.22 to 0.39 indicating a very good reservoir quality and reflecting probably well sorted coarse-grained sandstone reservoirs. The permeability of the reservoirs ranges from 288 mD to 1250mD and this suggests good reservoir horizons. The hydrocarbon saturation of the reservoirs ranges from 0.59 to 0.71 indicating that the proportion of void spaces occupied by water is low consequently high hydrocarbon production. Sand-shale lithology was calculated, with sandstone volume decreasing with increasing depth, while shale volume increases with depth. Porosity and permeability showed decreasing trend with depth for both sandstone and shale units in all wells with few exceptions. This could be as a result of low compaction by overburden pressure from overlying rocks. Plot of lithology versus depth reveals that shale lithology increases with depth, while sandstone decreases. Lithology versus porosity plots show an inverse relationship between permeability and shale volume and direct relationship between permeability and volume of sand. Lithology versus permeability shows that permeability and shale volume have an inverse relationship whereas permeability and volume of sand have a direct relationship. Permeability decreases exponentially with decrease in porosity in rock matrix made up of intercalation of sandstone and shale. The modelled equation of permeability and porosity is given by K = 0.053e32.934Ф. This implies that in the absence of core and well-log data, permeability can be estimated using only porosity data. The results of this work can be used as an exploration tool for the identification of prospective areas and also for feasibility studies during an appraisal activity.
Pages 33-42
Year 2019
Issue 2
Volume 3

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mjg.02.2019.12.22

ABSTRACT

IMPLICATION OF RESERVOIR CHARACTERISTICS BASED ON OVERVIEW OF STRUCTURE AND SEDIMENTOLOGY OF OUTCROPS ALONG BINTULU-NIAH-MIRI AREAS

Journal: Malaysian Journal of Geosciences (MJG)
Author: Jong E Cheng

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2019.12.22

Six-day fieldwork was conducted in the north-west coast of Sarawak to examine the outcrops along Bintulu- Niah- Miri areas which cover southern part of Balingian Province and Baram Delta Province. The aim of this fieldwork is to synthesize the observations of structure and sedimentology of outcrops along Bintulu-Niah-Miri areas and discuss the implication of reservoir characteristics based on observation. The study was conducted by sketching the main structural elements of outcrops followed by detailed sedimentological analysis which include observation and facies description were conducted on different outcrops along Bintulu-Niah- Miri areas using sedimentary logs. The findings show that Bintulu- Niah- Miri areas outcrops consists of mixed-environment deposited succession with tidal and wave characteristic. This resulted in reservoir architect will be different and result in different in reservoir properties included horizontal and vertical permeability of fluids. Niah Cave is a good place to study the distribution of the types of breccia due to collapsed paleokarst at reservoir scale and also good analog for Central Luconia Platform where large resources of hydrocarbon have been discovered due to the its environment setting or forming process is same as Central Luconia Platform. In addition, Miri Airport Outcrop succession consist of Type 4- Fracture Create Flow Barriers which could lead to potential production problems.
Pages 12-22
Year 2019
Issue 2
Volume 3

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mjg.02.2019.07.11

ABSTRACT

ASSESSING SUSPENDED SEDIMENT YIELD IN THE SAF SAF GAUGED CATCHMENT, NORTHEASTERN ALGERIA

Journal: Malaysian Journal of Geosciences (MJG)
Author: K. Khanchoul, Z.A. Boukhrissa

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2019.07.11

Many studies on sediment transport have been carried out on Algerian rivers but few studies have been undertaken in catchments of the Northeast of Algeria. The scarcity or discontinuity on sediment transport measurements reduces knowledge about soil loss. In some cases, researchers find often difficulties to apply the most suitable methods to estimate sediment load. The present work represents an assessment of suspended sediment yield from the Saf Saf catchment (322 km2) over 39 years. Long-term annual suspended sediment loads are estimated using non-linear power model, developed on mean discharge class technique as a sediment rating curve. There is a challenge to estimate suspended sediment load in the Saf Saf catchment, which is distinguished by rapid discharge variation. A second aim is to examine monthly and annual variations in discharge, suspended concentration, rainfall and load in this river and to find causes for these variations. The results show that the mean annual sediment yield is equal to 477 T km-2 yr-1 during the study period. Moreover, the long term variability analysis of sediment load seems to be very high from year to year depending on climatic conditions. The analysis of annual sediment load shows a decreasing trend along 39 years, mainly from 1997. Most sediment loads are transported during the winter season, which represents 78% of the total sediment load. The understanding of sediment transport relationships gained from this study should provide a good starting point for researchers and policymakers to begin addressing sediment issues within the catchment.
Pages 07-11
Year 2019
Issue 2
Volume 3

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mjg.02.2019.01.06

ABSTRACT

ENGINEERING GEOLOGICAL INVESTIGATION ON KARAMBUNAI-LOK BUNUQ LANDSLIDES, KOTA KINABALU, SABAH

Journal: Malaysian Journal of Geosciences (MJG)
Author: Md. Rodeano Roslee

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2019.01.06

This paper describes landslide occurrences in debris materials, together with its engineering geological and geotechnical setting. The predictions from conventional geotechnical slope stability analyses, taking into account topography, hydrological, geotechnical and engineering geological effects, are compared with the observed pattern of instability. Physical and mechanical properties of eight (8) soil samples indicated that the failure materials mainly consist of poorly graded materials of sandy clay soils and characterized by low to intermediate plasticity, containing of normal clay (0.42 to 0.95), very high degree of swelling (5.63 to 10.35), variable low to high water content (11.95 % to 19.92 %), specific gravity ranges from 2.60 to 2.68, low permeability (6.68 X 10-4 to 1.52 X 10-4 cm/s), friction angle () ranges from 18.50˚ to 34.20˚ and cohesion (C) ranges from 3.36 kN/m2 to 19.50 kN/m2 with very soft to soft of undrained shear strength (9.47 kN/m2 to 32.30 kN/m2). Geotechnical limit equilibrium stability analyses of entire slopes are rarely able to predict the smaller-scale initiation events leading to landslide occurrences, because the se are controlled by local topography, water runoff and groundwater conditions, weathered materials and engineering geological setting. Slope stability analysis shows that the factor of safety value is ranges from 0.805 to 0.817 (unstable). It is concluded that the failures was debris flow and resulted from a combination of factors. Engineering geological evaluation should be prioritized and take into consideration in the initial step in all infrastructure program. Development planning has to consider the geohazard and geoenvironmental management program. This engineering geological study may play a vital role in slope stability assessment to ensure public safety.
Pages 01-06
Year 2019
Issue 2
Volume 3

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mjg.02.2017.01.05

ABSTRACT

Flood mitigation measres using intuitionistic fuzzy dematel method

Journal: Malaysian Journal of Geosciences (MJG)

Author: Norzanah Abd Rahman, Zamali Tarmudi, Munirah Rossdy, Fatihah Anas Muhiddin

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.01.05

Flood is a natural disaster induced by climate change that resulted in the losses of lives, damages to property, and disrupts the daily activities of local community. Thus, the flood mitigation measures are developed to reduce the impact of flood in our country. The aim of this paper is; to propose IF-DEMATEL method and deal with the uncertainty of input data set of flood mitigation measures, and to validate it using sensitivity analysis. Here, this method is used for flood mitigation measures comprise drainage improvements, barriers, wet flood proofing, dry flood proofing, elevation, relocation, and acquisition. A numerical example from the flood control project selection proposed by a researcher which was adopted to show the applicability of the proposed method. The result shows that the flood mitigation measures are placed based on their priority. Although the rank of flood mitigation measures is sensitive to changes based on the weight of criteria but the best measures is remaining unchanged.
Pages 01-05
Year 2017
Issue 2
Volume 1

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mjg.02.2017.06.09

ABSTRACT

Estimation of peak ground acceleration of ranau based on recent eartqhuake databases

Journal: Malaysian Journal of Geosciences (MJG)
Author: Noor Sheena Herayani Binti Harith, Azlan Adnan

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.06.09

The occurrence of earthquake with magnitude MW 6.0 in Ranau recently has triggered many questions regarding their nature of recurrence, characteristics in size and mechanism in and its surrounding region. In recent years, Sabah has witnessed an increase in low to moderate seismic activities due to the causative ground structures which reflected in their seismic productivities. Over the past years between 1900 until recently, magnitudes ranging from MW 2.9 to 6.0 were known to have occurred. While large magnitude earthquakes are fortunately rare, in the history of earthquakes, the region already experienced devastating earthquake including a magnitude of MW 5.8 on 26th July 1976 centred in Lahad Datu. The observation on earthquake catalogue spanning from 1900 to 2014 has been obtained from various earthquake data centers, Ranau previously recorded an earthquake with magnitude MW 5.1, the repeat over intervals of sudden large earthquake is considered to have much shorter recurrence intervals. This paper discusses the procedure for evaluating the probabilistic seismic hazard analysis (PSHA) whereas the peak ground acceleration (PGA) on bedrock of Ranau area for 10% and 2% probability of exceedance is taken into account. By analysing the correlation between the tectonic features and the available data on past seismicity, the estimation of PGA is based on smoothed-gridded seismicity with a subjectively chosen correlation distance of 50 km. The PGA estimation values for Ranau are approximately in the range of 80 to 140 cm/s2 that will be exceeded 10% probability of exceedance and 140 to 250 cm/s2 for 2% probability of exceedance.
Pages 06-09
Year 2017
Issue 2
Volume 1

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mjg.02.2017.10.12

ABSTRACT

Research on data management model of national defense mobilization potential based on geo spatial framework

Journal: Malaysian Journal of Geosciences (MJG)
Author: LI Guoming,CHEN Yanmin,YING Guowei,WU Xiaoping

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.10.12

At present, the national defense mobilization potential data is mainly unstructured data composed of text, images, report forms, lacking space attribute and location information. Therefore, a large study of national defense mobilization potential database has focused on data collection, reporting and information system construction, etc. To solve national defense mobilization potential data application problems in the construction of informatization, taking advantage of the characteristics of geographical spatial framework, this paper discusses national defense mobilization potential data management model based on geographical spatial framework.
Pages 10-12
Year 2017
Issue 2
Volume 1

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mjg.02.2017.13.19

ABSTRACT

Landslide susceptibility analysis lsa using weighted overlay method wom along the genting sempah to bentong highway pahang

Journal: Malaysian Journal of Geosciences (MJG)
Author: Rodeano Roslee, Alvyn Clancey Mickey, Norbert Simon, Mohd. Norazman Norhisham

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.13.19

This study focused on the Landslide Susceptibility Analysis (LSA) of the Karak highway, which link the Genting Sempah to Bentong area, Pahang. The physical relief of the study area is largely flat to undulating and moderately rough to steep mostly. The aims of this study are to identify the landslide prone area and to produce the Landslide Susceptibility Level (LSL) map using Weighted Overlay Method (WOM) integrated with Geographic Information System (GIS) and remote sensing techniques. Landslide locations were identified in the study area from imagery and aerial photograph interpretations followed by field work observation. The topographic, geologic data and satellite images were collected, processed and constructed into a spatial database using image processing. The factors that influence landslide occurrences such as slope gradient, slope aspect, topographic curvature and distance from drainage were retrieved from the topographic database. Geomorphology, lithology and geological structure were generated from the geologic database; whereas land use and soil types from SPOT satellite data image. Several areas are considered as susceptible, such as areas of Ladang Fook Who, Kg. Temiang, Ladang Ng Chin Siu, Kemajuan Tanah Genting Pandak, Kg. Lentang, Kg. Baharu Bt. Tinggi and Ladang Pandak. To avoid or minimize the landslide occurrences, development planning has to consider the hazard and environmental management program. This engineering geological study may play a vital role in Landslide Risk Management (LRM) to ensure the public safety.
Pages 13-19
Year 2017
Issue 2
Volume 1

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