IOP Conference Series: Earth and Environmental Science
Implementing the RGB color blending attribute of the decomposed spectral has been successfully co... more Implementing the RGB color blending attribute of the decomposed spectral has been successfully conducted for delineating the potential stratigraphic traps within the geomorphological elements of the studied interval from -1253ms to -800ms. The investigated area is situated in the peninsular Malaysia-Malay Basin and covering two neighbouring fields (Inas and Melor). Several fluvial system deposits dominate the studied interval. These interval’s time slices maps reveal several geomorphological features such as low meandering and superimposed fluvial channels system. Moreover, several structural elements and seismic artefacts are also delineated within the depositional sequences (DS-01-02) of Inas and Melor fields. The channel's sinuosity degree reflects the slope ratio of the substratum during the river's lifetime along the channel pathways. However, the low sinuosity of the main channel reflects the higher slope of the bedrock, while the high sinuousness of channels implies a...
3D-seismic data have increasingly shifted seismic interpretation work from a horizons-based to a ... more 3D-seismic data have increasingly shifted seismic interpretation work from a horizons-based to a volume-based focus over the past decade. The size of the identification and mapping work has therefore become difficult and requires faster and better tools. Faults, for instance, are one of the most significant features of subsurface geology interpreted from seismic data. Detailed fault interpretation is very important in reservoir characterization and modeling. The conventional manual fault picking is a time-consuming and inefficient process. It becomes more challenging and error-prone when dealing with poor quality seismic data under gas chimneys. Several seismic attributes are available for faults and discontinuity detection and are applied with varying degrees of success. We present a hybrid workflow that combines a semblance-based fault likelihood attribute with a conventional ant-tracking attribute. This innovative workflow generates optimized discontinuity volumes for fault detec...
IOP Conference Series: Earth and Environmental Science
Petroleum systems in offshore are often very complex and subtle because of variety of depositiona... more Petroleum systems in offshore are often very complex and subtle because of variety of depositional environments. Delineating a reservoir based on conventional seismic and well-log stratigraphic analysis in such complex settings often leads to uncertainties. A reliable model of reservoir can forecast the production and performance of a reservoir which can reduce the drilling risks and associated uncertainties significantly. This work is aimed to develop a new concept in reservoir modeling by integrating seismic inversion and rock physics tools. First, in order to define litho facies, rock physics modeling was carried out through well log analysis separately for each facie. Next, the available subsurface information is incorporated in a Bayesian engine which outputs the several realizations of elastic reservoir properties and their respective probabilities, which then are used for post-inversion analysis. Seismic inversion fully exploited the vast areal coverage of the seismic data an...
Journal of Petroleum Exploration and Production Technology, 2021
A substantial proportion of proven oil and gas reserves of the world is contained in the carbonat... more A substantial proportion of proven oil and gas reserves of the world is contained in the carbonate reservoir. It is estimated that about 60% of the world’s oil and 40% of gas reserves are confined in carbonate reservoirs. Exploration and development of hydrocarbons in carbonate reservoirs are much more challenging due to poor seismic imaging and reservoir heterogeneity caused by diagenetic changes. Evaluation of carbonate reservoirs has been a high priority for researchers and geoscientists working in the petroleum industry mainly due to the challenges presented by these highly heterogeneous reservoir rocks. It is essential for geoscientists, petrophysicists, and engineers to work together from initial phases of exploration and delineation of the pool through mature stages of production, to extract as much information as possible to produce maximum hydrocarbons from the field for the commercial viability of the project. In the absence of the well-log data, the properties are inferre...
This study identified the Pleistocene depositional succession of the group (A) (marine, estuarine... more This study identified the Pleistocene depositional succession of the group (A) (marine, estuarine, and fluvial depositional systems) of the Melor and Inas fields in the central Malay Basin from the seafloor to approximately −507 ms (522 m). During the last few years, hydrocarbon exploration in Malay Basin has moved to focus on stratigraphic traps, specifically those that existed with channel sands. These traps motivate carrying out this research to image and locate these kinds of traps. It can be difficult to determine if closely spaced-out channels and channel belts exist within several seismic sequences in map-view with proper seismic sequence geomorphic elements and stratigraphic surfaces seismic cross lines, or probably reinforce the auto-cyclic aggregational stacking of the avulsing rivers precisely. This analysis overcomes this challenge by combining well-log with three-dimensional (3D) seismic data to resolve the deposition stratigraphic discontinuities’ considerable resoluti...
Bawang Member (Unit 4) of Late Eocene age is the fifth and the youngest member of Belaga Formatio... more Bawang Member (Unit 4) of Late Eocene age is the fifth and the youngest member of Belaga Formation. In general, the Late Cretaceous to Late Eocene turbidite sequence of Rajang Group in the lower Rajang area (Central Sarawak) is characterized by Belaga Formation. This member is unique and is only exposed in the vicinity of the Tatau area (Arip valley and Tatau High region) with limited exposures. In this research we present new evidence, to support its position on the stratigraphic column, based on field observations (stratigraphic and sedimentological characteristics) and lab analysis (TOC). Numerous recently exposed sections were visited in the study area. Four litho-facies were identified in the Bawang Member based on sedimentological observations; (1) Massive sandstone facies (SF1), (2) Medium to thick-bedded sandstone facies (SF2), (3) Thin bedded heterolithic facies (SF3), and (4) Mudstone or Shale facies (SF4). Reddish maroon and green shales exposed in Tatau High region are o...
Geologists use the concept of seismic and sequence stratigraphy during hydrocarbon exploration an... more Geologists use the concept of seismic and sequence stratigraphy during hydrocarbon exploration and production stages at different scales. While seismic stratigraphy is applied at the exploration scale, sequence stratigraphy, on the other hand, following the concept of chronostratigraphy, is applied at the production scale using the vail concepts in relation to cores, wireline logs, and outcrops. In other words, seismic stratigraphy involves the interpretation of seismic reflection data by extracting geologic and stratigraphic information. Seismic sequence stratigraphy, therefore, can be further subdivided and in order to analyze a seismic sequence and depositional time units that are separated on the basis of identifying unconformities or seismic pattern changes. In contrast, seismic facies involve the delineation of depositional environments from the characteristics of seismic reflection data. This is achieved by examining reflection events or series of events through their lateral...
Offshore petroleum systems are often very complex and subtle because of a variety of depositional... more Offshore petroleum systems are often very complex and subtle because of a variety of depositional environments. Characterizing a reservoir based on conventional seismic and well-log stratigraphic analysis in intricate settings often leads to uncertainties. Drilling risks, as well as associated subsurface uncertainties can be minimized by accurate reservoir delineation. Moreover, a forecast can also be made about production and performance of a reservoir. This study is aimed to design a workflow in reservoir characterization by integrating seismic inversion, petrophysics and rock physics tools. Firstly, to define litho facies, rock physics modeling was carried out through well log analysis separately for each facies. Next, the available subsurface information is incorporated in a Bayesian engine which outputs several simulations of elastic reservoir properties, as well as their probabilities that were used for post-inversion analysis. Vast areal coverage of seismic and sparse vertica...
This study focuses on the sequence stratigraphy and the dominated seismic facies in the Central T... more This study focuses on the sequence stratigraphy and the dominated seismic facies in the Central Taranaki basin. Four regional seismic sequences namely SEQ4 to SEQ1 from bottom to top and four boundaries representing unconformities namely H4 to H1 from bottom to top have been traced based on the reflection terminations. This was validated using well logs information. An onlapping feature on the seismic section indicates a new perspective surface separated between the upper and lower Giant formation, which indicates a period of seawater encroachment. This study focused extensively on deposition units from SEQ4 to SEQ1. The seismic facies, isochron map, and depositional environment were determined, and the system tract was established. This study was also able to propose a new perspective sequence stratigraphy framework of the basin and probable hydrocarbon accumulations and from the general geological aspect, SA-Middle Giant Formation (SEQ3) could act as potential traps.
Hybrid event beds represent the combined effect of multiple geological processes, which result in... more Hybrid event beds represent the combined effect of multiple geological processes, which result in complex depositional geometries and distinct facies distribution in marine environments. Previous work on hybrid event beds highlights the classification, origin, and types of hybrid facies. However, in the present study, we discuss the development of hybrid event beds in submarine lobes with an emphasis on the analysis of proximal to distal, frontal to lateral relationships and evolution during lobe progradation. Detailed geological fieldwork was carried out in the classical deep-marine Late Paleogene Crocker Fan to understand the relationship between the character of hybrid bed facies and lobe architecture. The results indicate that hybrid facies of massive or structureless sandstone with mud clasts, clean to muddy sand, and chaotic muddy sand with oversized sand patch alternations (H1–H3) are well developed in proximal to medial lobes, while distal lobes mainly contain parallel to cr...
3D-seismic data have increasingly shifted seismic interpretation work from a horizons-based to a ... more 3D-seismic data have increasingly shifted seismic interpretation work from a horizons-based to a volume-based focus over the past decade. The size of the identification and mapping work has therefore become difficult and requires faster and better tools. Faults, for instance, are one of the most significant features of subsurface geology interpreted from seismic data. Detailed fault interpretation is very important in reservoir characterization and modeling. The conventional manual fault picking is a time-consuming and inefficient process. It becomes more challenging and error-prone when dealing with poor quality seismic data under gas chimneys. Several seismic attributes are available for faults and discontinuity detection and are applied with varying degrees of success. We present a hybrid workflow that combines a semblance-based fault likelihood attribute with a conventional ant-tracking attribute. This innovative workflow generates optimized discontinuity volumes for fault detec...
Deepwater lobes constitute a significant volume of submarine fans and are primarily believed to e... more Deepwater lobes constitute a significant volume of submarine fans and are primarily believed to exhibit a simple sheet geometry. However, recent studies interpret the geometries of these deep-marine lobes as distinct with respect to the complexity of the facies and their distribution. Hence, a conceptual model of deep-marine sediments is essential to discuss the deep-marine sediments associated with the fan and lobe architecture. The present study highlights the facies heterogeneity and distribution of various lobe elements at a multiscale level by considering a case study of the West Crocker Formation of Sabah in northwest Borneo. The formation was logged on a bed-to-bed scale from recently well-exposed sections, with a total vertical thickness of more than 300 m. The lithological characteristics, bed geometry, sedimentary textures and structures of individual beds were used to categorize the rock units into nine sedimentary lithofacies: five sandstone lithofacies (S1–S5), one hybr...
Sohail I. Qazi and SanLinn I. Kaka Earth Sciences Department King Fahd University of Petroleum an... more Sohail I. Qazi and SanLinn I. Kaka Earth Sciences Department King Fahd University of Petroleum and Minerals Dhahran 31261, Saudi Arabia We have compiled all relevant/available data including seismic and wireline log data to evaluate possible hydrocarbon exploration potential sites in the offshore Indus basin in Pakistan. The Indus basin is one of the least explored offshore regions where only twelve wells were drilled since 1961 with very little success. The basin is comparable to other hydrocarbon producing basins in terms of their age, sediment thickness, tectonic style and rock properties (Sattar, 2008). To date, very little has been explored to evaluate the possible hydrocarbon exploration potential sites in the offshore Indus basin. To fill this gap, we have carried out an integrated geophysical investigation using all relevant/available data in the offshore Indus basin. The Indus basin lies between the Murray Ridge and the Indian coast and is characterized by a wide shelf and ...
IOP Conference Series: Earth and Environmental Science
Implementing the RGB color blending attribute of the decomposed spectral has been successfully co... more Implementing the RGB color blending attribute of the decomposed spectral has been successfully conducted for delineating the potential stratigraphic traps within the geomorphological elements of the studied interval from -1253ms to -800ms. The investigated area is situated in the peninsular Malaysia-Malay Basin and covering two neighbouring fields (Inas and Melor). Several fluvial system deposits dominate the studied interval. These interval’s time slices maps reveal several geomorphological features such as low meandering and superimposed fluvial channels system. Moreover, several structural elements and seismic artefacts are also delineated within the depositional sequences (DS-01-02) of Inas and Melor fields. The channel's sinuosity degree reflects the slope ratio of the substratum during the river's lifetime along the channel pathways. However, the low sinuosity of the main channel reflects the higher slope of the bedrock, while the high sinuousness of channels implies a...
3D-seismic data have increasingly shifted seismic interpretation work from a horizons-based to a ... more 3D-seismic data have increasingly shifted seismic interpretation work from a horizons-based to a volume-based focus over the past decade. The size of the identification and mapping work has therefore become difficult and requires faster and better tools. Faults, for instance, are one of the most significant features of subsurface geology interpreted from seismic data. Detailed fault interpretation is very important in reservoir characterization and modeling. The conventional manual fault picking is a time-consuming and inefficient process. It becomes more challenging and error-prone when dealing with poor quality seismic data under gas chimneys. Several seismic attributes are available for faults and discontinuity detection and are applied with varying degrees of success. We present a hybrid workflow that combines a semblance-based fault likelihood attribute with a conventional ant-tracking attribute. This innovative workflow generates optimized discontinuity volumes for fault detec...
IOP Conference Series: Earth and Environmental Science
Petroleum systems in offshore are often very complex and subtle because of variety of depositiona... more Petroleum systems in offshore are often very complex and subtle because of variety of depositional environments. Delineating a reservoir based on conventional seismic and well-log stratigraphic analysis in such complex settings often leads to uncertainties. A reliable model of reservoir can forecast the production and performance of a reservoir which can reduce the drilling risks and associated uncertainties significantly. This work is aimed to develop a new concept in reservoir modeling by integrating seismic inversion and rock physics tools. First, in order to define litho facies, rock physics modeling was carried out through well log analysis separately for each facie. Next, the available subsurface information is incorporated in a Bayesian engine which outputs the several realizations of elastic reservoir properties and their respective probabilities, which then are used for post-inversion analysis. Seismic inversion fully exploited the vast areal coverage of the seismic data an...
Journal of Petroleum Exploration and Production Technology, 2021
A substantial proportion of proven oil and gas reserves of the world is contained in the carbonat... more A substantial proportion of proven oil and gas reserves of the world is contained in the carbonate reservoir. It is estimated that about 60% of the world’s oil and 40% of gas reserves are confined in carbonate reservoirs. Exploration and development of hydrocarbons in carbonate reservoirs are much more challenging due to poor seismic imaging and reservoir heterogeneity caused by diagenetic changes. Evaluation of carbonate reservoirs has been a high priority for researchers and geoscientists working in the petroleum industry mainly due to the challenges presented by these highly heterogeneous reservoir rocks. It is essential for geoscientists, petrophysicists, and engineers to work together from initial phases of exploration and delineation of the pool through mature stages of production, to extract as much information as possible to produce maximum hydrocarbons from the field for the commercial viability of the project. In the absence of the well-log data, the properties are inferre...
This study identified the Pleistocene depositional succession of the group (A) (marine, estuarine... more This study identified the Pleistocene depositional succession of the group (A) (marine, estuarine, and fluvial depositional systems) of the Melor and Inas fields in the central Malay Basin from the seafloor to approximately −507 ms (522 m). During the last few years, hydrocarbon exploration in Malay Basin has moved to focus on stratigraphic traps, specifically those that existed with channel sands. These traps motivate carrying out this research to image and locate these kinds of traps. It can be difficult to determine if closely spaced-out channels and channel belts exist within several seismic sequences in map-view with proper seismic sequence geomorphic elements and stratigraphic surfaces seismic cross lines, or probably reinforce the auto-cyclic aggregational stacking of the avulsing rivers precisely. This analysis overcomes this challenge by combining well-log with three-dimensional (3D) seismic data to resolve the deposition stratigraphic discontinuities’ considerable resoluti...
Bawang Member (Unit 4) of Late Eocene age is the fifth and the youngest member of Belaga Formatio... more Bawang Member (Unit 4) of Late Eocene age is the fifth and the youngest member of Belaga Formation. In general, the Late Cretaceous to Late Eocene turbidite sequence of Rajang Group in the lower Rajang area (Central Sarawak) is characterized by Belaga Formation. This member is unique and is only exposed in the vicinity of the Tatau area (Arip valley and Tatau High region) with limited exposures. In this research we present new evidence, to support its position on the stratigraphic column, based on field observations (stratigraphic and sedimentological characteristics) and lab analysis (TOC). Numerous recently exposed sections were visited in the study area. Four litho-facies were identified in the Bawang Member based on sedimentological observations; (1) Massive sandstone facies (SF1), (2) Medium to thick-bedded sandstone facies (SF2), (3) Thin bedded heterolithic facies (SF3), and (4) Mudstone or Shale facies (SF4). Reddish maroon and green shales exposed in Tatau High region are o...
Geologists use the concept of seismic and sequence stratigraphy during hydrocarbon exploration an... more Geologists use the concept of seismic and sequence stratigraphy during hydrocarbon exploration and production stages at different scales. While seismic stratigraphy is applied at the exploration scale, sequence stratigraphy, on the other hand, following the concept of chronostratigraphy, is applied at the production scale using the vail concepts in relation to cores, wireline logs, and outcrops. In other words, seismic stratigraphy involves the interpretation of seismic reflection data by extracting geologic and stratigraphic information. Seismic sequence stratigraphy, therefore, can be further subdivided and in order to analyze a seismic sequence and depositional time units that are separated on the basis of identifying unconformities or seismic pattern changes. In contrast, seismic facies involve the delineation of depositional environments from the characteristics of seismic reflection data. This is achieved by examining reflection events or series of events through their lateral...
Offshore petroleum systems are often very complex and subtle because of a variety of depositional... more Offshore petroleum systems are often very complex and subtle because of a variety of depositional environments. Characterizing a reservoir based on conventional seismic and well-log stratigraphic analysis in intricate settings often leads to uncertainties. Drilling risks, as well as associated subsurface uncertainties can be minimized by accurate reservoir delineation. Moreover, a forecast can also be made about production and performance of a reservoir. This study is aimed to design a workflow in reservoir characterization by integrating seismic inversion, petrophysics and rock physics tools. Firstly, to define litho facies, rock physics modeling was carried out through well log analysis separately for each facies. Next, the available subsurface information is incorporated in a Bayesian engine which outputs several simulations of elastic reservoir properties, as well as their probabilities that were used for post-inversion analysis. Vast areal coverage of seismic and sparse vertica...
This study focuses on the sequence stratigraphy and the dominated seismic facies in the Central T... more This study focuses on the sequence stratigraphy and the dominated seismic facies in the Central Taranaki basin. Four regional seismic sequences namely SEQ4 to SEQ1 from bottom to top and four boundaries representing unconformities namely H4 to H1 from bottom to top have been traced based on the reflection terminations. This was validated using well logs information. An onlapping feature on the seismic section indicates a new perspective surface separated between the upper and lower Giant formation, which indicates a period of seawater encroachment. This study focused extensively on deposition units from SEQ4 to SEQ1. The seismic facies, isochron map, and depositional environment were determined, and the system tract was established. This study was also able to propose a new perspective sequence stratigraphy framework of the basin and probable hydrocarbon accumulations and from the general geological aspect, SA-Middle Giant Formation (SEQ3) could act as potential traps.
Hybrid event beds represent the combined effect of multiple geological processes, which result in... more Hybrid event beds represent the combined effect of multiple geological processes, which result in complex depositional geometries and distinct facies distribution in marine environments. Previous work on hybrid event beds highlights the classification, origin, and types of hybrid facies. However, in the present study, we discuss the development of hybrid event beds in submarine lobes with an emphasis on the analysis of proximal to distal, frontal to lateral relationships and evolution during lobe progradation. Detailed geological fieldwork was carried out in the classical deep-marine Late Paleogene Crocker Fan to understand the relationship between the character of hybrid bed facies and lobe architecture. The results indicate that hybrid facies of massive or structureless sandstone with mud clasts, clean to muddy sand, and chaotic muddy sand with oversized sand patch alternations (H1–H3) are well developed in proximal to medial lobes, while distal lobes mainly contain parallel to cr...
3D-seismic data have increasingly shifted seismic interpretation work from a horizons-based to a ... more 3D-seismic data have increasingly shifted seismic interpretation work from a horizons-based to a volume-based focus over the past decade. The size of the identification and mapping work has therefore become difficult and requires faster and better tools. Faults, for instance, are one of the most significant features of subsurface geology interpreted from seismic data. Detailed fault interpretation is very important in reservoir characterization and modeling. The conventional manual fault picking is a time-consuming and inefficient process. It becomes more challenging and error-prone when dealing with poor quality seismic data under gas chimneys. Several seismic attributes are available for faults and discontinuity detection and are applied with varying degrees of success. We present a hybrid workflow that combines a semblance-based fault likelihood attribute with a conventional ant-tracking attribute. This innovative workflow generates optimized discontinuity volumes for fault detec...
Deepwater lobes constitute a significant volume of submarine fans and are primarily believed to e... more Deepwater lobes constitute a significant volume of submarine fans and are primarily believed to exhibit a simple sheet geometry. However, recent studies interpret the geometries of these deep-marine lobes as distinct with respect to the complexity of the facies and their distribution. Hence, a conceptual model of deep-marine sediments is essential to discuss the deep-marine sediments associated with the fan and lobe architecture. The present study highlights the facies heterogeneity and distribution of various lobe elements at a multiscale level by considering a case study of the West Crocker Formation of Sabah in northwest Borneo. The formation was logged on a bed-to-bed scale from recently well-exposed sections, with a total vertical thickness of more than 300 m. The lithological characteristics, bed geometry, sedimentary textures and structures of individual beds were used to categorize the rock units into nine sedimentary lithofacies: five sandstone lithofacies (S1–S5), one hybr...
Sohail I. Qazi and SanLinn I. Kaka Earth Sciences Department King Fahd University of Petroleum an... more Sohail I. Qazi and SanLinn I. Kaka Earth Sciences Department King Fahd University of Petroleum and Minerals Dhahran 31261, Saudi Arabia We have compiled all relevant/available data including seismic and wireline log data to evaluate possible hydrocarbon exploration potential sites in the offshore Indus basin in Pakistan. The Indus basin is one of the least explored offshore regions where only twelve wells were drilled since 1961 with very little success. The basin is comparable to other hydrocarbon producing basins in terms of their age, sediment thickness, tectonic style and rock properties (Sattar, 2008). To date, very little has been explored to evaluate the possible hydrocarbon exploration potential sites in the offshore Indus basin. To fill this gap, we have carried out an integrated geophysical investigation using all relevant/available data in the offshore Indus basin. The Indus basin lies between the Murray Ridge and the Indian coast and is characterized by a wide shelf and ...
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