Vertical and horizontal pressure depletion trends captured by AVA Geostatistical Inversion conditioned reservoir modeling: An example from Late Messinian lacustrine turbidities reservoirs, Nile Delta, Egypt.

2014 ◽  
Author(s):  
R. D. Vaughan ◽  
M. Ali ◽  
A. Mustafa ◽  
T. Adly ◽  
D. Sulistiono ◽  
...  
2019 ◽  
Vol 38 (6) ◽  
pp. 474-479
Author(s):  
Mohamed G. El-Behiry ◽  
Said M. Dahroug ◽  
Mohamed Elattar

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.


2020 ◽  
Vol 39 (3) ◽  
pp. 170-175
Author(s):  
Islam A. Mohamed ◽  
Adel Othman ◽  
Mohamed Fathy

In highly heterogeneous basins with complex subsurface geology, such as the Nile Delta Basin, accurate prediction of reservoir modeling has been a challenge. Reservoir modeling is a continuous process that begins with field discovery and ends with the last phases of production and abandonment. Currently, the stochastic reservoir modeling method is widely used instead of the traditional deterministic modeling method to consider spatial statistics and uncertainties. However, the modeling workflow is demanding and slow, typically requiring months from the initial model concept to flow simulation. In addition, errors from early model stages become cumulative and are difficult to change retroactively. To overcome these limitations, a new workflow is proposed that implements probabilistic neural network inversion to predict reservoir properties. First, well-log data were conditioned properly to match the seismic data scale. Then, the networks were trained and validated, using the conditioned well-log data and seismic internal/external attributes, to predict water saturation and effective porosity 3D volumes. The resulting volumes were sampled in simulation 3D grids and tested using a blind well test. Subsequently, the permeability was calculated from a porosity-permeability relationship inside the reservoir. Finally, a dynamic simulation project of the field was performed in which the historical field production and pressures were compared to the predicted values. One of the Pliocene deepwater turbidite reservoirs in the offshore Nile Delta was used to demonstrate the proposed approach. The results proved the accuracy of the model in predicting the reservoir properties and honoring the heterogeneity of the reservoir. The new approach represents a shortcut for the seismic-to-simulation process, providing a reliable and fast way of constructing a reservoir model and making the seismic-to-simulation process easier.


2019 ◽  
Vol 158 ◽  
pp. 103546
Author(s):  
Esam A. Abd El-Gawad ◽  
Mohammad A. Abdelwahhab ◽  
Mahmoud H. Bekiet ◽  
Ahmed Z. Noah ◽  
Nahla A. ElSayed ◽  
...  

2008 ◽  
Author(s):  
Ahmed Mohamed Daoud ◽  
Osama Hegazy ◽  
Yasser Hazem ◽  
Mohamed Lotfy ◽  
Samir Youssef ◽  
...  

2019 ◽  
Vol 7 (2) ◽  
pp. T455-T465 ◽  
Author(s):  
Islam A. Mohamed ◽  
Mahmoud Hemdan ◽  
Ahmed Hosny ◽  
Mohamed Rashidy

One of the main challenges that we face is the accurate prediction of pore-fluid properties with the highest possible resolution. The seismic resolution is the most limiting factor, especially in our case, in which the main reservoirs are deepwater turbidite channels and their thin beds typically fall below the seismic tuning thickness. Therefore, we designed a new workflow that combines the geostatistical inversion and the neural network analysis with the aim of predicting a 3D high-resolution water saturation (sampled every 1 ms), overcoming the limitation of seismic detectability and providing better reservoir characterization. The power of the geostatistical inversion is that it provides multiple model realizations, and each realization honors the well data (statistical information and logs) and the seismic data. These realizations are more reliable and high-resolution versions of the elastic parameters. On the other hand, the main advantage of the neural network is that it establishes a stable nonlinear link between the input seismic and inversion results and the target water saturation. The available data set for this study includes three angle stacks and seven wells from Scarab field, offshore Nile Delta. The resulted high-resolution saturation volume was tested using blind-well analysis and revisit post the drilling of a new well later on. It gave spectacular results in both cases. The normalized correlations between the predicted saturation volume and the real saturation logs are 0.87 and 0.89, respectively. The results prove the validity of the workflow to accurately predict water saturation with a higher resolution than ever before.


Author(s):  
N. Blet ◽  
Vincent Ayel ◽  
Yves Bertin ◽  
Cyril Romestant ◽  
Vincent Platel

2007 ◽  
Author(s):  
James Keggin ◽  
Walter Rietveld ◽  
Mark Benson ◽  
Ted Manning ◽  
Peter Cook ◽  
...  
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document