Characterizing complex slope channel reservoirs applying Extended Elastic Impedance, Saffron gas field, offshore Nile Delta, Egypt

2020 ◽  
Author(s):  
Adel A. A. Othman ◽  
Farouk Ibrahim Metwally ◽  
Mohamed F. M. Ali ◽  
Ahmed Saied Ali
Keyword(s):  
Nile Delta ◽  
Gas Field ◽  
Elastic Impedance ◽  
Slope Channel

Characterizing complex slope channel reservoirs applying extended elastic impedance, Saffron gas field, offshore Nile Delta, Egypt

2021 ◽  
Vol 40 (2) ◽  
pp. 151a1-151a7
Author(s):  
Adel Othman ◽  
Ahmed Ali ◽  
Mohamed Fathi ◽  
Farouk Metwally
Keyword(s):  
Water Saturation ◽  
Nile Delta ◽  
Seismic Attributes ◽  
Significant Degree ◽  
Seismic Inversion ◽  
Gas Field ◽  
Amplitude Variation With Offset ◽  
3D Volume ◽  
Elastic Impedance ◽  
Sand Bodies

In a complex reservoir with a significant degree of heterogeneity, it is a challenge to characterize the reservoir using different seismic attributes based on available data within certain time constraints. Prestack seismic inversion and amplitude variation with offset are among the techniques that give excellent results, particularly for gas-bearing clastic reservoir delineation because of the remarkable contrast between the latter and the surrounding rocks. Challenges arise when a shortage of seismic or well data presents an obstacle in applying these techniques. A further challenge arises if it is necessary to predict water saturation (Sw) using the seismic data because of the independent nonlinear relationship between Sw and seismic attributes and inversion products. Prediction of Sw is necessary not only for characterizing pay from nonpay reservoirs but also for economic reasons. Therefore, extended elastic impedance has been performed to produce a 3D volume of Sw over the reservoir interval. Then, a 3D sweetness volume and spectral decomposition volumes were used to grasp the geometry of the sand bodies that have been charged with gas in addition to their connectivity. This could help illustrate the different stages in the evolution of the Saffron channel system and the sand bodies distribution, both vertically and spatially, and consequently increase production and decrease development risk.

scholarly journals Extended Elastic Impedance Inversion for Better Delineation of Gasbearing Sand Reservoir, Saffron Gas Field, Offshore Nile Delta, Egypt

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Othman AAA ◽  
◽  
Ali MFM ◽  
Metwally FI ◽  
Ali AS ◽  
...  
Keyword(s):  
Seismic Data ◽  
Nile Delta ◽  
Petrophysical Properties ◽  
Gas Field ◽  
Fluid Content ◽  
Impedance Inversion ◽  
Gradient Domain ◽  
The Difference ◽  
Elastic Impedance ◽  
Seismic Anomaly

Extended Elastic Impedance (EEI) is a very useful seismic reconnaissance attribute. EEI logs can directly correspond to the petrophysical properties of the reservoir and the seismic. EEI reflectivity volumes can be obtained directly from the pre-stack seismic data. Better discrimination between the seismic anomaly caused by either lithology or fluid content can be utilized by applying this approach. The concept of extended elastic impedance is used to derive the petrophysical properties and distribute the reservoir facies. The study area was a Pliocene gas field, that lies in the deep marine, Offshore Nile Delta, Egypt. The workflow is simple, efficient, and uses very few inputs. We started with the fluid/ lithology logs and investigated the optimum projection in the intercept/gradient domain. Then, we used the conditioned angle stacks, to calculate the intercept/ gradient volumes, using Shuey’s two-term Approximation. The intercept and gradient volumes are converted directly to the fluid and lithology 3D volumes, without any of the pre-stack inversion constraints. The outputs were tested using a blind well and the correlation exceeds 80%. The results show that the EEI is a worthy effort to highlight the difference between the reservoir and nonreservoir sections, to identify the hydrocarbon area.

Application of geostatistical seismic inversion in reservoir characterization of Sapphire gas field, offshore Nile Delta, Egypt

2019 ◽  
Vol 38 (6) ◽  
pp. 474-479
Author(s):  
Mohamed G. El-Behiry ◽  
Said M. Dahroug ◽  
Mohamed Elattar
Keyword(s):  
Reservoir Characterization ◽  
Nile Delta ◽  
Seismic Inversion ◽  
Reservoir Modeling ◽  
Connectivity Analysis ◽  
Gas Field ◽  
Geostatistical Inversion ◽  
Well Data ◽  
Reservoir Connectivity ◽  
Inversion Techniques

Seismic reservoir characterization becomes challenging when reservoir thickness goes beyond the limits of seismic resolution. Geostatistical inversion techniques are being considered to overcome the resolution limitations of conventional inversion methods and to provide an intuitive understanding of subsurface uncertainty. Geostatistical inversion was applied on a highly compartmentalized area of Sapphire gas field, offshore Nile Delta, Egypt, with the aim of understanding the distribution of thin sands and their impact on reservoir connectivity. The integration of high-resolution well data with seismic partial-angle-stack volumes into geostatistical inversion has resulted in multiple elastic property realizations at the desired resolution. The multitude of inverted elastic properties are analyzed to improve reservoir characterization and reflect the inversion nonuniqueness. These property realizations are then classified into facies probability cubes and ranked based on pay sand volumes to quantify the volumetric uncertainty in static reservoir modeling. Stochastic connectivity analysis was also applied on facies models to assess the possible connected volumes. Sand connectivity analysis showed that the connected pay sand volume derived from the posterior mean of property realizations, which is analogous to deterministic inversion, is much smaller than the volumes generated by any high-frequency realization. This observation supports the role of thin interbed reservoirs in facilitating connectivity between the main sand units.

scholarly journals Permeability Prediction Using Hydraulic Flow Units: Baltim North Gas Field, Nile Delta, Egypt

2021 ◽  
Vol 12 (02) ◽  
pp. 57-76
Author(s):  
Abdel Moktader A. El Sayed ◽  
Samy Zayed ◽  
Nahla A. El Sayed
Keyword(s):  
Nile Delta ◽  
Gas Field ◽  
Hydraulic Flow ◽  
Permeability Prediction ◽  
Flow Units ◽  
Hydraulic Flow Units

scholarly journals Formation evaluation and reservoir characteristics of the Messinian Abu Madi sandstones in Faraskour Gas Field, onshore Nile Delta, Egypt

2020 ◽  
Author(s):  
Mahmoud Leila ◽  
Ali Eslam ◽  
Asmaa Abu El-Magd ◽  
Lobna Alwaan ◽  
Ahmed Elgendy
Keyword(s):  
Water Saturation ◽  
Nile Delta ◽  
Hydrocarbon Exploration ◽  
The Other ◽  
Reservoir Rock ◽  
Reservoir Quality ◽  
Pore System ◽  
Reservoir Properties ◽  
Gas Field ◽  
Irreducible Water Saturation

Abstract The Messinian Abu Madi Formation represents the most prospective reservoir target in the Nile Delta. Hydrocarbon exploration endeavors in Nile Delta over the last few decades highlighted some uncertainties related to the predictability and distribution of the Abu Madi best reservoir quality facies. Therefore, this study aims at delineating the factors controlling the petrophysical heterogeneity of the Abu Madi reservoir facies in Faraskour Field, northeastern onshore part of the Nile Delta. This work provides the very first investigation on the reservoir properties of Abu Madi succession outside the main canyon system. In the study area, Abu Madi reservoir is subdivided into two sandstone units (lower fluvial and upper estuarine). Compositionally, quartzose sandstones (quartz > 65%) are more common in the fluvial unit, whereas the estuarine sandstones are often argillaceous (clays > 15%) and glauconitic (glauconite > 10%). The sandstones were classified into four reservoir rock types (RRTI, RRTII, RRTIII, and RRTIV) having different petrophysical characteristics and fluid flow properties. RRTI hosts the quartzose sandstones characterized by mega pore spaces (R35 > 45 µm) and a very well-connected, isotropic pore system. On the other side, RRTIV constitutes the lowest reservoir quality argillaceous sandstones containing meso- and micro-sized pores (R35 > 5 µm) and a pore system dominated by dead ends. Irreducible water saturation increases steadily from RRTI (Swir ~ 5%) to RRTIV (Swir > 20%). Additionally, the gas–water two-phase co-flowing characteristics decrease significantly from RRTI to RRTIV facies. The gaseous hydrocarbons will be able to flow in RRTI facies even at water saturation values exceeding 90%. On the other side, the gas will not be able to displace water in RRTIV sandstones even at water saturation values as low as 40%. Similarly, the influence of confining pressure on porosity and permeability destruction significantly increases from RRTI to RRTIV. Accordingly, RRTI facies are the best reservoir targets and have high potentiality for primary porosity preservation.

scholarly journals Reservoir Rock Genetic Types Using Log Curve Shapes: Abu- Madi Formation, Offshore Nile Delta - Baltim Gas Field, Egypt

2019 ◽  
Vol 221 ◽  
pp. 012045
Author(s):  
Abdel Moktader A. El Sayed ◽  
Nahla A. El Sayed ◽  
Amir Lala ◽  
M. Metwally
Keyword(s):  
Nile Delta ◽  
Reservoir Rock ◽  
Gas Field ◽  
Genetic Types

scholarly journals Analysis of Petroleum System for Exploration and Risk Reduction in Abu Madi/Elqar'a Gas Field, Nile Delta, Egypt

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Said Keshta ◽  
Farouk J. Metwalli ◽  
H. S. Al Arabi
Keyword(s):  
Nile Delta ◽  
Organic Matter Content ◽  
Petroleum System ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Basin Modeling ◽  
Burial History ◽  
Gas Field ◽  
Upper Miocene ◽  
Migration Pathways

Abu Madi/El Qar'a is a giant field located in the north eastern part of Nile Delta and is an important hydrocarbon province in Egypt, but the origin of hydrocarbons and their migration are not fully understood. In this paper, organic matter content, type, and maturity of source rocks have been evaluated and integrated with the results of basin modeling to improve our understanding of burial history and timing of hydrocarbon generation. Modeling of the empirical data of source rock suggests that the Abu Madi formation entered the oil in the middle to upper Miocene, while the Sidi Salem formation entered the oil window in the lower Miocene. Charge risks increase in the deeper basin megasequences in which migration hydrocarbons must traverse the basin updip. The migration pathways were principally lateral ramps and faults which enabled migration into the shallower middle to upper Miocene reservoirs. Basin modeling that incorporated an analysis of the petroleum system in the Abu Madi/El Qar'a field can help guide the next exploration phase, while oil exploration is now focused along post-late Miocene migration paths. These results suggest that deeper sections may have reservoirs charged with significant unrealized gas potential.

Elastic Impedance Inversion in the Western Nile Delta, a Case Study

2004 ◽  
Author(s):  
R. Roberts ◽  
J. Bedingfield ◽  
D. Phelps ◽  
A. Lau ◽  
B. Godfrey ◽  
...  
Keyword(s):  
Nile Delta ◽  
Impedance Inversion ◽  
Elastic Impedance
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