Papers by Ahmed E. Radwan
Frontiers in Earth Science
Future gas field development and prospect assessment depend on accurate reservoir parameter chara... more Future gas field development and prospect assessment depend on accurate reservoir parameter characterization. The understanding of the tight sand distribution of the Shanxi and Taiyuan Formations within the Hangjinqi area is ambiguous due to the presence of coal and mudstone lithofacies, high heterogeneity, and poor resolution of the seismic data. Thus, it is difficult to determine the reservoir’s thickness. To cope with this challenge, we have employed the advanced method of constrained sparse spike inversion (CSSI) utilizing 3D seismic and nine wells for the distinction of tight sandstone facies from the coal and mudstone facies. Results of petrophysical analysis of studied well J54 show that the coal and mudstone facies are dominant towards the T9c horizon, whereas tight sandstone facies are present towards the T9d horizon. The obtained findings show that the CSSI accurately identified the spatial distribution of sand-ratio in the zone of interest (ZOI) that lies between the T9c ...
Journal of Applied Geophysics, 2016
This review focuses on the recent applications of nuclear magnetic resonance (NMR) technology for... more This review focuses on the recent applications of nuclear magnetic resonance (NMR) technology for characterizing fractures. The paper aims to help researchers in extending the existing reservoir characterization methods (which are commonly used in conventional hydrocarbon reservoirs) for appropriate usage in unconventional resources. This is because some techniques for quantifying and qualifying fractures have been investigated in conventional sandstone and carbonate reservoirs, but the reality for unconventional resources is that such techniques are still poorly developed. Fractures are necessary for economical production of petroleum from many low-permeability reservoirs. The characterization of fractures by well logging technology is of great interest in the petroleum industry. The main purpose of this study is to review the characterization techniques that are developed either for identifying fractures or distinguishing fracture porosity from matrix porosity. This concept plays a leading role in providing availability of an optimized well completion program. The results of this study indicated that in terms of both sandstone and carbonate tight reservoirs, there have not been many steps taken toward the aforementioned goal up to now. Nevertheless, these steps are valuable enough to be counted on and could serve a meaningful function in treating hydrocarbon reservoirs. Because of the ongoing changes in today's petroleum industry, development of a comprehensive methodology will create greater economic benefits in unconventional reservoirs than in the conventional ones.
Marine and Petroleum Geology, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Petroleum Exploration and Production Technology
Sand production is one of the major challenges in the oil and gas industry, so a comprehensive ge... more Sand production is one of the major challenges in the oil and gas industry, so a comprehensive geomechanical analysis is necessary to mitigate sand production in mature fields. As the pore pressure drastically decline in depleted reservoirs, the sand production risk becomes more critical and needs to be studied. However, the absence of key logs in many wells is a big challenge in the petroleum industry, and most geologists and engineers use empirical equations to predict missed log intervals. We conducted a comprehensive geomechanical modeling study on a full set of logs from two wells from the Hilal field, Gulf of Suez, Egypt, to infer the geomechanical elements and predict sand production. We have used the multi-arm calipers to calculate the actual depth of damage ratio to validate the geomechanical parameters in the prognosis model and confirm the stress orientations. We used machine learning approach to infer key sonic log in X-10 well to replace the empirical equations. The mul...
Energies
Most old oil and gas fields worldwide are depleted, making drilling in these sedimentary zones ex... more Most old oil and gas fields worldwide are depleted, making drilling in these sedimentary zones extremely difficult, especially in complex pore pressure regimes when they are accompanied by over-pressure zones. Considering that typical wellbore stability studies provide a conservative mud density curve to prevent wellbore failure, dynamic geomechanical approaches are required to provide more flexible and manageable drilling in such complex cases in order to address anticipated drilling obstacles. This study aims to apply the more dynamic concept, known as “depth of damage” (DOD), in the El Morgan oil field, Gulf of Suez Basin, to deliver a more optional mud density window that helps in the safe drilling of different pore pressure regimes within the area, as well as the implications of applying this drilling strategy in the studied basin. In this paper, well logging and downhole measurements were used to develop a 1D geomechanical earth model and infer the in situ stresses in the stud...
Natural Resources Research
Understanding the depositional setting of siliciclastics reservoir is fundamental process to expl... more Understanding the depositional setting of siliciclastics reservoir is fundamental process to exploration and development of hydrocarbon reservoirs and to the multi-phase cycle of the oil and gas industry. Typically, core samples from existing or potential reservoirs can be used for interpretation of depositional environment. However, the lack of core samples in certain reservoirs represents a challenge for reservoir development plans and further exploration. To overcome the absence of core samples in the middle Miocene Sidri Member in the Badri field, Gulf of Suez, this study aimed to reconstruct its depositional settings by coupling well logging patterns and petrographic characterization of ditch cuttings. Consequently, 30 thin section samples representing the reservoir section of four wells were described in detail and standard petrographic characteristics were determined. Then, gamma-ray (GR) log patterns of the studied reservoir wells were used for interpretation of depositional...
Natural Resources Research
The Coniacian–Santonian Matulla Formation is one of the important reservoirs in the July oilfield... more The Coniacian–Santonian Matulla Formation is one of the important reservoirs in the July oilfield, Gulf of Suez Basin. However, this formation is characterized by uncertainty due to the complexity of reservoir architecture, various lithologies, lateral facies variations and heterogeneous reservoir quality. These reservoir challenges, in turn, affect the effectiveness of further exploitation of this reservoir along the Gulf of Suez Basin. In this work, we conduct an integrated study using multidisciplinary datasets and techniques to determine the precise structural, petrophysical, and facies characteristics of the Matulla Formation and predict their complex geometry in 3D space. To complete this study, 30 2D seismic sections, five digital well logs, and core samples of 75 ft (ft = 0.3048 m) length were used to build 3D models for the Matulla reservoir. The 3D structural model shows strong lateral variation in thickness of the Matulla Formation with NW–SE, NE–SW and N–S fault directio...
Sustainable Geoscience for Natural Gas Subsurface Systems
Interpretation
Reservoir damage is considered one of the major challenges in the oil and gas industry. Many stud... more Reservoir damage is considered one of the major challenges in the oil and gas industry. Many studies have been conducted to understand formation damage mechanisms in borehole wells, but few studies have been conducted to analyze the data to detect the source, causes, and mitigations for each well where damage has occurred. I have investigated and quantified the reasons and mitigation of reservoir damage problems in the middle Miocene reservoir within the El Morgan oil field at the southern central Gulf of Suez, Egypt. I used integrated production, reservoir, and geologic data sets and their history during different operations to assess the reservoir damage in El Morgan-XX well. The collected data include the reservoir rock type, fluid, production, core analysis, rock mineralogy, geology, water chemistry, drilling fluids, perforations depth intervals, workover operations, and stimulation history. The integration of different sets of data gave a robust analysis of reservoir damage cau...
Journal of Petroleum Exploration and Production Technology
One of the challenges in reservoir management is determining the fracture density (FVDC) in reser... more One of the challenges in reservoir management is determining the fracture density (FVDC) in reservoir rock. Given the high cost of coring operations and image logs, the ability to predict FVDC from various petrophysical input variables using a supervised learning basis calibrated to the standard well is extremely useful. In this study, a novel machine learning approach is developed to predict FVDC from 12-input variable well-log based on feature selection. To predict the FVDC, combination of two networks of multiple extreme learning machines (MELM) and multi-layer perceptron (MLP) hybrid algorithm with a combination of genetic algorithm (GA) and particle swarm optimizer (PSO) has been used. We use a novel MELM-PSO/GA combination that has never been used before, and the best comparison result between MELM-PSO-related models with performance test data is RMSE = 0.0047 1/m; R2 = 0.9931. According to the performance accuracy analysis, the models are MLP-PSO
Journal of Asian Earth Sciences
Arabian Journal for Science and Engineering
Reservoir formation damage is a major problem that the oil and gas industry has to mitigate in or... more Reservoir formation damage is a major problem that the oil and gas industry has to mitigate in order to maintain the oil and gas supply. A case study is presented that identifies the impacts of formation damage and their causes in the Nubian ‘C’ hydrocarbon reservoir within Sidki field located in the Southern Gulf of Suez, Egypt. In addition, a formation damage mitigation program was designed and implemented involving an effective stimulation treatment for each well experiencing reservoir damage. The data available for this study include core analysis to provide rock mineralogy and lithology; analysis of production fluid data; water chemistry; drilling fluid composition; perforations and well completion details; workover operations; and stimulation history. The diagnosis of formation damage based on the integrated assessment of the available data is associated with several benefits, (1) The integration of the data available helps provide a robust analysis of formation damage causes ...
Natural Resources Research
Waterflooding is one of the most common secondary recovery methods in the oil and gas industry. G... more Waterflooding is one of the most common secondary recovery methods in the oil and gas industry. Globally, this process sometimes suffers a technical failure and inefficiency. Therefore, a better understanding of geology, reservoir characteristics, rock typing and discrimination, hydraulic flow units, and production data is essential to analyze reasons and mechanisms of water injection failure in the injection wells. Water injection failure was reported in the Middle Miocene Hammam Faraun reservoir at El Morgan oil field in the Gulf of Suez, where two wells have been selected as injector’s wells. In the first well (A1), the efficiency of injection was not good, whereas in the other analog A2 well good efficiency was assigned. Therefore, it is required to assess the injection loss in the low efficiency well, where all aspects of the geological, reservoir and production data of the studied wells were integrated to get a complete vision for the reasons of injection failure. The availabl...
Natural Resources Research
Waterflooding is one of the most common secondary recovery methods in the oil and gas industry. G... more Waterflooding is one of the most common secondary recovery methods in the oil and gas industry. Globally, this process sometimes suffers a technical failure and inefficiency. Therefore, a better understanding of geology, reservoir characteristics, rock typing and discrimination, hydraulic flow units, and production data is essential to analyze reasons and mechanisms of water injection failure in the injection wells. Water injection failure was reported in the Middle Miocene Hammam Faraun reservoir at El Morgan oil field in the Gulf of Suez, where two wells have been selected as injector’s wells. In the first well (A1), the efficiency of injection was not good, whereas in the other analog A2 well good efficiency was assigned. Therefore, it is required to assess the injection loss in the low efficiency well, where all aspects of the geological, reservoir and production data of the studied wells were integrated to get a complete vision for the reasons of injection failure. The availabl...
petroleum science and engineering
The thick Eocene carbonate deposits that are newly ascribed as Radwany Formation (previously Theb... more The thick Eocene carbonate deposits that are newly ascribed as Radwany Formation (previously Thebes Formation) in the October basin within the Gulf of Suez region, are of particular interest for hydrocarbon exploitation. However, no efforts have been directed to investigate their petrophysical characteristics and pore system. This study aims to investigate the petrophysical characteristic, pore system and formation potentiality as a reservoir rock. Thirteen sidewall core samples and sixty thin sections from OCT-X well were studied in order to investigate the lithological characteristics, porosity network. In addition, well logging data and petrophysical and geochemical laboratories measurements including Nuclear Magnetic Resonance (NMR) porosity technique were used to define the petrophysical characteristics. The investigated work revealed that: 1) the pore system is a combination of depositional and diagenetic processes. 2) the dominant porosity types include fracture, interparticle, intra-particle and moldic porosity; NMR indicates mesopores to macropores, 3) petrophysical evaluation and geochemical analysis indicates a self-sourced unconventional reservoir based on its organic richness characteristics unconventional resource opportunity as tight carbonate reservoir, 4) the basal part of the Radwany Formation has a high potential to store hydrocarbon, and it is a potential conventional resource. 6) The linking trends between the petrophysical parameters with sediment microfacies were defined in the studied section, where a significant increasing trend line has been inferred in the direction from wackestone microfacies to packstone microfacies. Finally, the diagenetic process through time has greatly controlled the petrophysical parameters of the Radwany Formation. The gap between Source and Reservoir rocks has been defined based on integrated geochemical and petrophysical characteristics. The studied section has unique multiscale characterization as unconventional and conventional resource.
Natural Resources Research, 2020
Understanding the depositional setting of siliciclastics reservoir is fundamental process to
expl... more Understanding the depositional setting of siliciclastics reservoir is fundamental process to
exploration and development of hydrocarbon reservoirs and to the multi-phase cycle of the
oil and gas industry. Typically, core samples from existing or potential reservoirs can be used
for interpretation of depositional environment. However, the lack of core samples in certain
reservoirs represents a challenge for reservoir development plans and further exploration.
To overcome the absence of core samples in the middle Miocene Sidri Member in the Badri
field, Gulf of Suez, this study aimed to reconstruct its depositional settings by coupling well
logging patterns and petrographic characterization of ditch cuttings. Consequently, 30 thin
section samples representing the reservoir section of four wells were described in detail and
standard petrographic characteristics were determined. Then, gamma-ray (GR) log patterns
of the studied reservoir wells were used for interpretation of depositional environment.
Petrographic analysis indicates that the sandstone reservoir is fine- to medium-grained arkose
with dominant siliceous cement and composed mainly of quartz, feldspars, and lithic
fragments. Pores reflecting primary and secondary porosity as well as inter-granular pores
are dominant. The facies analysis indicates that the studied member has a heterogeneous
nature and rapid facies change; its main lithofacies are blocky sandstones, intercalated
sandstones and shales, and shales. Three electrofacies were interpreted in the studied section:
(1) electrofacies-A (blocky sandstones), which is characterized by a cylindrical-shaped
(right boxcar) GR trend; (2) electrofacies-B (intercalated sandstones and shales), which is
characterized by an irregular log trend with serrated shape; and (3) electrofacies-C (shales),
which is characterized by irregular GR trend and has no character. The interpreted results
indicate a tidal channel depositional setting for electrofacies-A, mixed tidal flat depositional
setting for electrofacies-B, and low relief offshore mudstone depositional setting for electrofacies-
C. Finally, the results illustrate how the coupling of GR patterns with the analysis
of petrographic characteristics can be used to understand the depositional setting of a
hydrocarbon reservoir that lacks core samples. This work could be useful for assessment of
reservoir distribution and quality, for reduction of uncertainty during field development, as
well as for providing useful insight to similar hydrocarbon reservoirs elsewhere.
The Gulf of Suez in Egypt has a north-northwest–south-southeast
orientation and is located at the... more The Gulf of Suez in Egypt has a north-northwest–south-southeast
orientation and is located at the junction of the African and Arabian
plates where it separates the northeast African continent from the
Sinai Peninsula. It has excellent hydrocarbon potential, with the
prospective sedimentary basin area measuring approximately
19,000 km2, and it is considered as the most prolific oil province
rift basin in Africa and the Middle East. This basin contains more
than 80 oil fields, with reserves ranging from 1350 to less than 1
million bbl, in reservoirs of Precambrian to Quaternary age. The
lithostratigraphic units in the Gulf of Suez can be subdivided into
three megasequences: a prerift succession (pre-Miocene or Paleozoic–
Eocene), a synrift succession (Oligocene–Miocene), and a
postrift succession (post-Miocene or Pliocene–Holocene). These
units vary in lithology, thickness, areal distribution, depositional
environment, and hydrocarbon importance. Geological and geophysical
data show that the northern and central Gulf of Suez consist
of several narrow, elongated depositional troughs, whereas the
southern part is dominated by a tilt-block terrane, containing numerous
offset linear highs.
Major prerift and synrift source rocks have potential to yield oil
and/or gas and are mature enough in the deep kitchens to generate
hydrocarbons. Geochemical parameters, sterane distribution, and
biomarker correlations are consistent with oils generated from marine
source rocks. Oils in the Gulf of Suez were sourced from potential
source rock intervals in the prerift succession that are typically
oil prone (type I), and in places oil and gas prone (type II), or
are composites of more than one type (multiple types I, II, or III
for oil prone, oil and gas prone, or gas prone, respectively).
The reservoirs can be classified into prerift reservoirs, such as
the Precambrian granitic rocks, Paleozoic–Cretaceous Nubian sandstones,
Upper Cretaceous Nezzazat sandstones and the fractured
Eocene Thebes limestone; and synrift reservoirs, such the Miocene
sandstones and carbonates of the Nukhul, Rudeis, Kareem, and Belayim
formations and the sandstones of South Gharib, Zeit, andpost-Zeit. The majority of oil fields in the region incorporate
multiple productive reservoirs. Miocene
evaporites are the ultimate hydrocarbon seals, whereas
the shale and dense limestones of the prerift and the
synrift stratigraphic units are the primary seals. Structural,
stratigraphic, and combination traps are encountered
in the study area. The Gulf of Suez is the most
prolific and prospective oil province in Egypt, and any
open acreage, or relinquished area, will be of great interest
to the oil industry.
basics carbonate petrophysics
A reservoir geomechanical modeling has been attempted in the hydrocarbon-bearing Miocene formatio... more A reservoir geomechanical modeling has been attempted in the hydrocarbon-bearing Miocene formations in the offshore Badri field, Gulf of Suez, Egypt. Pore pressure established from the direct downhole measurements indicated sub-hydrostatic condition in the depleted mid-Miocene Hammam Faraun and Kareem reservoirs. Vertical stress (S v) estimated using bulk density data yielded an average of 0.98 PSI/feet (22.17 MPa/km) gradient. Magnitudes of minimum (S hmin) and maximum (S hmax) horizontal stresses were deduced from the poro-elastic model. Relative stress magnitudes (S v ‡ S hmax > S hmin) reflect a normal faulting tectonic stress in the Badri field. Pore pressure and stress perturbations (DPP and DS h) in the depleted reservoirs investigated from actual measurements recognized Ôstress pathÕ values of 0.54 and 0.59 against the Hammam Faraun and Kareem Formations, respectively. These stress path values are far away from the normal faulting limit (0.68), indicating induced normal faulting or fault reactivation to be unlikely at the present depletion rate.
Typically pressure gradients and density-neutron crossover are used to differentiate between rese... more Typically pressure gradients and density-neutron crossover are used to differentiate between reservoir water, oil and gas. This study investigates fluid type in the Badri Field, Sidri sandstone reservoir of four offshore wells, A, B, C and D. These wells lack pressure or well test data and density-neutron fluid interpretation remain equivocal. In addition, these wells have not been tested before. Hence, a new technique adopted from the geochemical fingerprint technique termed petrophysical fingerprint has been used to distinguish equivocal petrophysical characteristics. In this study, the petrophysical fingerprint was used to distinguish fluids, a combination of synthetic and raw logs was plotted on crossplots charts and correlated to previous oil and gas well tests. This study revealed that, 1) the Petrophysical Fingerprint technique was found to clarify otherwise ambivalent log responses, lending confidence to the Badri Field interpretation, 2) the petrophysical fingerprint strategy showed notable results, resulted in gas signature fingerprint in the well B, while showing an oil signature fingerprint in wells C and D. 3) In comparison to the traditional plotting method, the petrophysical fingerprint technique has the advantages that the correlation between the obtained petrophysical fingerprints of the individual petro-physical characters and the unknown investigated petrophysical character will increase the precision of the petrophysical investigation process, which in turn will guarantee a reliable judgment on the investigated pet-rophysical properties, 4) the authors refer to some caution, where more or less homogeneous reservoir characteristics are preferred to correlate petrophysical fingerprints signatures, else at least the reservoir to be not highly heterogeneous, where homogeneous reservoirs are not common in reality.
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Papers by Ahmed E. Radwan
exploration and development of hydrocarbon reservoirs and to the multi-phase cycle of the
oil and gas industry. Typically, core samples from existing or potential reservoirs can be used
for interpretation of depositional environment. However, the lack of core samples in certain
reservoirs represents a challenge for reservoir development plans and further exploration.
To overcome the absence of core samples in the middle Miocene Sidri Member in the Badri
field, Gulf of Suez, this study aimed to reconstruct its depositional settings by coupling well
logging patterns and petrographic characterization of ditch cuttings. Consequently, 30 thin
section samples representing the reservoir section of four wells were described in detail and
standard petrographic characteristics were determined. Then, gamma-ray (GR) log patterns
of the studied reservoir wells were used for interpretation of depositional environment.
Petrographic analysis indicates that the sandstone reservoir is fine- to medium-grained arkose
with dominant siliceous cement and composed mainly of quartz, feldspars, and lithic
fragments. Pores reflecting primary and secondary porosity as well as inter-granular pores
are dominant. The facies analysis indicates that the studied member has a heterogeneous
nature and rapid facies change; its main lithofacies are blocky sandstones, intercalated
sandstones and shales, and shales. Three electrofacies were interpreted in the studied section:
(1) electrofacies-A (blocky sandstones), which is characterized by a cylindrical-shaped
(right boxcar) GR trend; (2) electrofacies-B (intercalated sandstones and shales), which is
characterized by an irregular log trend with serrated shape; and (3) electrofacies-C (shales),
which is characterized by irregular GR trend and has no character. The interpreted results
indicate a tidal channel depositional setting for electrofacies-A, mixed tidal flat depositional
setting for electrofacies-B, and low relief offshore mudstone depositional setting for electrofacies-
C. Finally, the results illustrate how the coupling of GR patterns with the analysis
of petrographic characteristics can be used to understand the depositional setting of a
hydrocarbon reservoir that lacks core samples. This work could be useful for assessment of
reservoir distribution and quality, for reduction of uncertainty during field development, as
well as for providing useful insight to similar hydrocarbon reservoirs elsewhere.
orientation and is located at the junction of the African and Arabian
plates where it separates the northeast African continent from the
Sinai Peninsula. It has excellent hydrocarbon potential, with the
prospective sedimentary basin area measuring approximately
19,000 km2, and it is considered as the most prolific oil province
rift basin in Africa and the Middle East. This basin contains more
than 80 oil fields, with reserves ranging from 1350 to less than 1
million bbl, in reservoirs of Precambrian to Quaternary age. The
lithostratigraphic units in the Gulf of Suez can be subdivided into
three megasequences: a prerift succession (pre-Miocene or Paleozoic–
Eocene), a synrift succession (Oligocene–Miocene), and a
postrift succession (post-Miocene or Pliocene–Holocene). These
units vary in lithology, thickness, areal distribution, depositional
environment, and hydrocarbon importance. Geological and geophysical
data show that the northern and central Gulf of Suez consist
of several narrow, elongated depositional troughs, whereas the
southern part is dominated by a tilt-block terrane, containing numerous
offset linear highs.
Major prerift and synrift source rocks have potential to yield oil
and/or gas and are mature enough in the deep kitchens to generate
hydrocarbons. Geochemical parameters, sterane distribution, and
biomarker correlations are consistent with oils generated from marine
source rocks. Oils in the Gulf of Suez were sourced from potential
source rock intervals in the prerift succession that are typically
oil prone (type I), and in places oil and gas prone (type II), or
are composites of more than one type (multiple types I, II, or III
for oil prone, oil and gas prone, or gas prone, respectively).
The reservoirs can be classified into prerift reservoirs, such as
the Precambrian granitic rocks, Paleozoic–Cretaceous Nubian sandstones,
Upper Cretaceous Nezzazat sandstones and the fractured
Eocene Thebes limestone; and synrift reservoirs, such the Miocene
sandstones and carbonates of the Nukhul, Rudeis, Kareem, and Belayim
formations and the sandstones of South Gharib, Zeit, andpost-Zeit. The majority of oil fields in the region incorporate
multiple productive reservoirs. Miocene
evaporites are the ultimate hydrocarbon seals, whereas
the shale and dense limestones of the prerift and the
synrift stratigraphic units are the primary seals. Structural,
stratigraphic, and combination traps are encountered
in the study area. The Gulf of Suez is the most
prolific and prospective oil province in Egypt, and any
open acreage, or relinquished area, will be of great interest
to the oil industry.
exploration and development of hydrocarbon reservoirs and to the multi-phase cycle of the
oil and gas industry. Typically, core samples from existing or potential reservoirs can be used
for interpretation of depositional environment. However, the lack of core samples in certain
reservoirs represents a challenge for reservoir development plans and further exploration.
To overcome the absence of core samples in the middle Miocene Sidri Member in the Badri
field, Gulf of Suez, this study aimed to reconstruct its depositional settings by coupling well
logging patterns and petrographic characterization of ditch cuttings. Consequently, 30 thin
section samples representing the reservoir section of four wells were described in detail and
standard petrographic characteristics were determined. Then, gamma-ray (GR) log patterns
of the studied reservoir wells were used for interpretation of depositional environment.
Petrographic analysis indicates that the sandstone reservoir is fine- to medium-grained arkose
with dominant siliceous cement and composed mainly of quartz, feldspars, and lithic
fragments. Pores reflecting primary and secondary porosity as well as inter-granular pores
are dominant. The facies analysis indicates that the studied member has a heterogeneous
nature and rapid facies change; its main lithofacies are blocky sandstones, intercalated
sandstones and shales, and shales. Three electrofacies were interpreted in the studied section:
(1) electrofacies-A (blocky sandstones), which is characterized by a cylindrical-shaped
(right boxcar) GR trend; (2) electrofacies-B (intercalated sandstones and shales), which is
characterized by an irregular log trend with serrated shape; and (3) electrofacies-C (shales),
which is characterized by irregular GR trend and has no character. The interpreted results
indicate a tidal channel depositional setting for electrofacies-A, mixed tidal flat depositional
setting for electrofacies-B, and low relief offshore mudstone depositional setting for electrofacies-
C. Finally, the results illustrate how the coupling of GR patterns with the analysis
of petrographic characteristics can be used to understand the depositional setting of a
hydrocarbon reservoir that lacks core samples. This work could be useful for assessment of
reservoir distribution and quality, for reduction of uncertainty during field development, as
well as for providing useful insight to similar hydrocarbon reservoirs elsewhere.
orientation and is located at the junction of the African and Arabian
plates where it separates the northeast African continent from the
Sinai Peninsula. It has excellent hydrocarbon potential, with the
prospective sedimentary basin area measuring approximately
19,000 km2, and it is considered as the most prolific oil province
rift basin in Africa and the Middle East. This basin contains more
than 80 oil fields, with reserves ranging from 1350 to less than 1
million bbl, in reservoirs of Precambrian to Quaternary age. The
lithostratigraphic units in the Gulf of Suez can be subdivided into
three megasequences: a prerift succession (pre-Miocene or Paleozoic–
Eocene), a synrift succession (Oligocene–Miocene), and a
postrift succession (post-Miocene or Pliocene–Holocene). These
units vary in lithology, thickness, areal distribution, depositional
environment, and hydrocarbon importance. Geological and geophysical
data show that the northern and central Gulf of Suez consist
of several narrow, elongated depositional troughs, whereas the
southern part is dominated by a tilt-block terrane, containing numerous
offset linear highs.
Major prerift and synrift source rocks have potential to yield oil
and/or gas and are mature enough in the deep kitchens to generate
hydrocarbons. Geochemical parameters, sterane distribution, and
biomarker correlations are consistent with oils generated from marine
source rocks. Oils in the Gulf of Suez were sourced from potential
source rock intervals in the prerift succession that are typically
oil prone (type I), and in places oil and gas prone (type II), or
are composites of more than one type (multiple types I, II, or III
for oil prone, oil and gas prone, or gas prone, respectively).
The reservoirs can be classified into prerift reservoirs, such as
the Precambrian granitic rocks, Paleozoic–Cretaceous Nubian sandstones,
Upper Cretaceous Nezzazat sandstones and the fractured
Eocene Thebes limestone; and synrift reservoirs, such the Miocene
sandstones and carbonates of the Nukhul, Rudeis, Kareem, and Belayim
formations and the sandstones of South Gharib, Zeit, andpost-Zeit. The majority of oil fields in the region incorporate
multiple productive reservoirs. Miocene
evaporites are the ultimate hydrocarbon seals, whereas
the shale and dense limestones of the prerift and the
synrift stratigraphic units are the primary seals. Structural,
stratigraphic, and combination traps are encountered
in the study area. The Gulf of Suez is the most
prolific and prospective oil province in Egypt, and any
open acreage, or relinquished area, will be of great interest
to the oil industry.