New Methodology for 3-D Reservoir Modeling Leads to Retrieving the Complexity of Limited Drilled Wells and Improving Development Decision Making for a Clastic Gas Reservoir, Qawasim Formation, Onshore Nile Delta

2012 ◽  
Author(s):  
Ahmed Reda ◽  
Abdel Hakim Hashem ◽  
M. Darwish ◽  
Mohamed El Ghanam
Keyword(s):  
Decision Making ◽  
Nile Delta ◽  
Reservoir Modeling ◽  
Gas Reservoir

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.

A new exploration tool for subtle stratigraphic traps in the offshore Nile Delta, Egypt

2019 ◽  
Vol 26 (3) ◽  
pp. 434-447
Author(s):  
Amir M. S. Lala ◽  
Amr Talaat
Keyword(s):  
Seismic Data ◽  
Nile Delta ◽  
The Other ◽  
Class I ◽  
Class Iii ◽  
Gas Reservoir ◽  
Seismic Amplitude ◽  
Amplitude Anomaly ◽  
Exploration Tool ◽  
Gas Bearing

The offshore Nile Delta Basin is considered as one of the most promising hydrocarbon provinces in Egypt, with an excellent potential for gas and condensate reserves following future exploration. Most of the discoveries in this basin, such as the reservoirs of the Upper Miocene and the Middle–Upper Pliocene, have been enabled by the use of a direct hydrocarbon indicator (DHI), based on a class III seismic amplitude v. offset (AVO) anomaly. However, there are gas-bearing formations in the Lower Pliocene that have been successfully tested where the sand did not show any seismic amplitude anomaly in full stacks or in near- and far-offset sub-stacks. The AVO analysis of this sand reservoir is referred to as AVO class II-P. Another case of a subtle AVO class I anomaly in a Lower Pliocene gas reservoir has also been tested by three wells.These variations in AVO types push us to find a new methodology to reduce the risk of unsuccessful exploration wells, mainly using seismic data. The enhanced AVO pseudo-gradient attribute (EAP) has previously been used in other studies, mainly to highlight AVO class III anomalies. However, in the present paper, we demonstrate a workflow to identify all the principal AVO classes observed in this province. Computing the EAP attribute from our data, we find that AVO class I has negative EAP values, while the other classes have positive values. Class III and classes II and II-P may be distinguished from each other as the former yields a strong positive EAP value, whereas the latter two classes yield weak EAP responses.After determining the AVO class, we define and use a new model attribute, herein termed NM, to differentiate between gas- and water-bearing formations for each class of AVO anomaly found in this province. This new method was successfully tested in many areas in the Nile Delta Basin, where it has helped to identify subtle anomalies and thereby open the gate for further exploration activities in the area.

scholarly journals Risk Decision-Making Technology in Gas Reservoir Development at Sichuan Basin

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Guo Yu ◽  
Haitao Li ◽  
Yanru Chen ◽  
Linqing Liu ◽  
Dongming Zhang
Keyword(s):  
Risk Factors ◽  
Decision Making ◽  
Stochastic Simulation ◽  
Development Planning ◽  
Gas Reservoir ◽  
Probability Curve ◽  
Scanning Method ◽  
Reservoir Development ◽  
Risk Grade ◽  
Risk Decision

During the development of complex gas reservoirs, the risk decision-making problem often emerges. Thus, the study on risk assessment is an important tool used to identify potential hazards and create appropriate avoidance measures accordingly. Based on the analysis of seven types of risk factors in gas reservoir development planning, this paper aims to clarify the logical relationship between the risk factors in the strategic planning of natural gas development. The comprehensive research on target risks in the gas reservoir development planning based on stochastic simulation was carried out. The “probability curve scanning method” was used to evaluate objective risk factors, while the decision-making risk factors were evaluated using the “probability curve displacement method.” According to the realization probability and dispersion degree of the planned target combined with the risk grade evaluation matrix, the planning target evaluation risk grade was implemented. Moreover, the planning unit risk grade evaluation was obtained at different stages. Regarding the specific production capacity conditions in gas wells (horizontal and vertical wells) and gas reservoir water invasion, the probability method with Monte Carlo stochastic simulation was used to calculate the production and water invasion volumes. The established decision-making risk technology for gas reservoir development, along with the associated supporting procedures, can be used to evaluate the risks of reservoir development planning, production, and water invasion.

Sign in / Sign up

Export Citation Format

Share Document