scholarly journals Gas-generative potential for the post-Messinian megasequence of Nile Delta Basin: a case study of Tao Field, North Sinai Concession, Egypt

Author(s):  
Mohammad Abdelfattah Sarhan

AbstractThe main aim of the article is to evaluate the gas potentiality for the post-Messinian megasequence in TAO Field, North Sinai Concession, offshore Nile Delta Basin. The detailed petrophysical analysis for three deviated wells in the study area (Tao-3 ST1 Well, Tao-5 STA Well and Tao-7 Well) revealed that the Pliocene Kafr El-Sheikh Formation includes eleven gas-bearing zones. These zones were named: A, B, C in Tao-3 ST1 Well and D, E, F in Tao-5 STA Well. In Tao-7 Well, the interesting zones are named G, H, I, J and K. All of these sandy intervals are relatively shallow in depth and differ in thickness between 4 and 56 m. These zones are characterized by shale volume (10%), total porosity (30–40%), effective porosity (30–35%), gas saturation (50–90%), high effective permeability to gas and low permeability to water. The seismic data displayed that listric faults and the associated rollover folds have an important role in forming structural traps for the examined gas-bearing zones in Tao Field and its surroundings. This work revealed that the success rate in discovering new gas prospects within the Pliocene–Pleistocene succession at North Sinai Concession is very high.

2021 ◽  
Vol 24 (11) ◽  
pp. 1941-1947
Author(s):  
C Eze ◽  
G Emujakporue ◽  
DC Okujagu

Petrophysical-Modelling is indispensable in upstream Projects, considering the high cost, risks and uncertainties associated with this sector. Petrophysical qualities for Queen Field was modeled using Information obtained and analyzed from well-logs and 3-D Seismic data. Coarse-grain, Medium- grain and fine-grain Sands as well as Shale were all delineated by GR log. Results of petrophysical evaluation conducted on seven reservoir intervals correlated across the field showed that; Shale volume was below 35%, Total Porosity are > 20% Effective Porosity are >15% Permeability is > 380.00mD all of this conforms to excellent reservoir quantity. Seismic interpretation showed the presence of synthetic and antithetic faults. Two horizons were mapped on seismic data and utilized for modeling. These models were the framework for facies and petrophysical properties distribution. Facies models were generated using sequential indicator simulation while petrophysical properties were generated using sequential gaussian simulation algorithm. A comparison was further done between facies constrained and non-facies constrained models. It was found that for Porosity, Permeability, Water of Saturation and Shale Volume Models not constrained to facies all showed overestimated Models, in addition Stochastic STOIIP not constrained to facies gave an Over Estimated P50 value for Surface I and O Reservoir Interval as 624.028M, 76.28MM, when compared to Stochastic Hydrocarbon STOIIP when constrained to facies that showed Stochastic P50 value of 513,247 and 67.04MM for surface I and O and Deterministic STOIIP of 742.90M and 87.88MM. This study validates the practice of constraining Petrophysical model to facies available on the field as the best practice. Keywords: Queen Field, Onshore, Niger Delta, 3D Petrophysical.


2019 ◽  
Vol 26 (3) ◽  
pp. 434-447
Author(s):  
Amir M. S. Lala ◽  
Amr Talaat

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.


2007 ◽  
Author(s):  
Robert Marten ◽  
Walter Rietveld ◽  
Mark Benson ◽  
Alaa Khodeir ◽  
James Keggin ◽  
...  

Author(s):  
S. M. Talha Qadri ◽  
Md Aminul Islam ◽  
Mohamed Ragab Shalaby ◽  
Ahmed K. Abd El-Aal

AbstractThe study used the sedimentological and well log-based petrophysical analysis to evaluate the Farewell sandstone, the reservoir formation within the Kupe South Field. The sedimentological analysis was based on the data sets from Kupe South-1 to 5 wells, comprising the grain size, permeability, porosity, the total cement concentrations, and imprints of diagenetic processes on the reservoir formation. Moreover, well log analysis was carried on the four wells namely Kupe South 1, 2, 5 and 7 wells for evaluating the parameters e.g., shale volume, total and effective porosity, water wetness and hydrocarbon saturation, which influence the reservoir quality. The results from the sedimentological analysis demonstrated that the Farewell sandstone is compositionally varying from feldspathic arenite to lithic arenite. The analysis also showed the presence of significant total porosity and permeability fluctuating between 10.2 and 26.2% and 0.43–1376 mD, respectively. The diagenetic processes revealed the presence of authigenic clay and carbonate obstructing the pore spaces along with the occurrence of well-connected secondary and hybrid pores which eventually improved the reservoir quality of the Farewell sandstone. The well log analysis showed the presence of low shale volume between 10.9 and 29%, very good total and effective porosity values ranging from 19 to 32.3% as well as from 17 to 27%, respectively. The water saturation ranged from 22.3 to 44.9% and a significant hydrocarbon saturation fluctuating from 55.1 to 77.7% was also observed. The well log analysis also indicated the existence of nine hydrocarbon-bearing zones. The integrated findings from sedimentological and well log analyses verified the Farewell sandstone as a good reservoir formation.


Author(s):  
Mohammad Abdelfattah Sarhan

AbstractIn this work, the petrophysical properties of Abu Madi reservoir in El-Qara Field at northern Nile Delta Basin (NDB) were evaluated depending on well logging data of two wells: El-Qara-2 and El-Qara-3. This evaluation revealed that in El-Qara-2 well, the promising gas zone is detected between depths of 3315 and 3358 m, while in El-Qara-3 well, the best gas interval is detected between depths of 3358 and 3371 m. In addition to the production test parameters (gas rate, condensate rate, gas gravity, condensate gravity, gas-to-oil ratio, flowing tubing head pressure, flowing bottom hole pressure, and static bottom hole pressure), the calculated petrophysical parameters (shale volume, total porosity, effective porosity, and water saturation) for both intervals were relatively similar. This confirms that the investigated wells were drilled at the same reservoir interval within Abu Madi Fm. The depth variation in the examined zones was attributed to the presence of buried normal faults between El-Qara-2 and El-Qara-3 wells. This observation may be supported from the tectonic influence during the deposition of Abu Madi Fm. as a portion of the Messinian syn-rift megasequence beneath the NDB.


2021 ◽  
Vol 11 (7) ◽  
pp. 2877-2890
Author(s):  
Mohammad Abdelfattah Sarhan

AbstractNukhul Formation is one of the primary oil reservoirs in the Gulf of Suez Basin. Rabeh East is an oil producer field located at the southern border of the Gulf of Suez. The present work deals with the geophysical investigation of Nukhul Formation in Rabeh East field using seismic lines and well log data of four wells, namely RE-8, RE-22, RE-25 and Nageh-1. The interpreted seismic profiles display that the RE-8 Well is the only well drilled within the up-thrown side of a significant horst fault block bounded by two normal faults. However, the other wells penetrated the downthrown side. The qualitative interpretation of the well logging data for RE-8 Well delineated two intervals have good petrophysical parameters and ability to store and produce oil. These zones locate between depths 5411.5 and 5424 ft (zone I) and between 5451 and 5459.5 ft (zone II). The calculated petrophysical parameters for zone I display water saturation (22–44%), shale volume (10–23%), total porosity (18–23%), effective porosity (12–20%) and bulk volume of water (0.04–0.06). Zone II exhibits water saturation (13–45%), shale volume (10–30%), total porosity (18–24%), effective porosity (11–20%) and bulk volume of water (0.03–0.05). This analysis reflects excellent petrophysical characteristics for the sandstones of Nukhul Formation in Rabeh East oil field for producing oil if the wells drilled in a suitable structural closure.


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