A Study of Microfacies and Petrophysical Analysis of Some Subsurface Cretaceous Rocks of Abu Gharadig-34 Well,Western Desert,Egypt

Abstract

The main aim of this study is to shed light on the microfacies association, petrophysical parameters, and depositional environment of different rocks such as sandstone, limestone, shale, siltstone, and dolomite of subsurface Cretaceous rock units (Abu Roash “C” member, Abu Roash “E” Member, and Bahariya Formation) from Abu Gharadig-34 well in the north western desert, Egypt. In this study, nine microfacies were identified. These microfacies include calcareous siltstone, bioclastic wackstone, ferruginous sublithic arenite, dolomitic lithic arenite, lithic arenite, fossiliferous bioclastic wackstone, glauconitic dolomitic sublithic arenite, ferroan dolomite, and ferruginous sandy siltstone. Generally, subsurface Cretaceous rock units are deposited in different depositional environments ranging from tidal flats to open circulation passes through restricted circulation shelves. Statistical analysis of the petrophysical data showed that the highest porosity was concentrated at Abu Roash “C” member, which had very good porosity and high permeability. The porosity increased when the bulk density decreased. The permeability of the studied samples was the same as the porosity, which increased when the bulk density decreased. It can be concluded that Abu Roash “C” member is a good reservoir in the Abu Gharadig-34 well.     

Potentiality and timing of generation of Kareem and Rudeis formations,Central Gulf of Suez

This study aims to evaluate source rock formations (Kareem and Rudeis) through quantitative and qualitative analysis of pyrolysis data from 44 ditch samples from three wells (Elkhaligue-1, Kareem-1, and El Ayune-1) at different depths in the central Gulf of Suez. From these data we concluded that Kareem and Rudeis formations are fair to good source rocks and have a generating potential fair to good to generate both oil and gas generated from mixed type II kerogene deposited under anoxic conditions, also they considered as fair to good oil sources. Both formations are mature and this conclusion is confirms by the burial histories of the three wells where Kareem Formation reached the early stage of generation at time ranges from 6 to 1.5?m.y while Rudeis Formation reached the oil window at time ranges from 18 to 6.6?m.y which considered a very good timing for excellent preservation efficiency of the hydrocarbons generated.     

埃及技术法规标准体系及其特点

本文通过剖析埃及的进出口贸易概况、法律法规和标准体系，总结其体系特点，以期为从事中埃经贸合作的企业和机构提供快捷便利的技术指导。     

Detection of prospective areas for mineralization deposits using image analysis technique of aeromagnetic data around Marsa Alam-Idfu road,Eastern Desert,Egypt

Area around Marsa Alam-Idfu road is considered as one of the most prospective regions for gold and base metals mineralization in Egypt. The total intensity aeromagnetic reduced to northern magnetic pole (RTP) data of such area revealed that a set of parallel continuous linear features taken NNW-SSE trend with variable magnetic amplitudes, which are related to faults, dykes and shear zones. Also, this map showed strong negative and positive magnetic anomalies generated in contact zones, which may be considered with the linear features as prospective areas for mineralization.The application of centre for exploration targeting (CET) grid image analysis technique was applied for the aeromagnetic data of such area for rapidly locating regions perceived to be most favorable for gold and base metals deposits. The technique generated a series of high structural complexity maps which are combined to create an overall prospectively map that defined regions of high potentially for mineral deposits.Integration of the obtained results from the resulted maps and the RTP magnetic map, aided by the geological information revealed that a good correlation between the known gold and base metals locations and the regions of mineralization that are generated by the proposed technique. Besides, additionally locations of gold and base metals deposits were found on the generated map. These new locations are suggestive of where the mineralization may occur. The derived locations of these mineralization are aligned along definite trends, which are arranged according to their magnitude and importance as NNE-SSW, NW-SE, NNW-SSE, E-W and NE-SW directions. Serpentine rocks and their contacts with the surrounding rocks could be considered valuable as gold mineralization zones of economic importance and are considered as significant targets for follow-up and ground investigations.     

Middle–Upper Jurassic palynology of the South Sallum well,North Western Desert,Egypt

Palynological analyses have been carried out on some samples of Middle–Upper Jurassic from the South Sallum well, North Western Desert, Egypt. A refinement of the original chronostratigraphy has been suggested and the stages of Bathonian – Callovian and the Callovian – Oxfordian are recognized. Two biozones were identified that are Dichadogonyaulax sellwoodi i – Wanaea acollaris – Wanaea digitata Assemblage Zone in the Bathonian – Callovian and Amphorula dodekovae Interval Zone in the Callovian – Oxfordian. Other important dinoflagellates and miospores of Middle–Upper Jurassic are recorded in the samples. The palaeoenvironmental settings are interpreted on the basis of statistical relative abundances of the palynomorphs, in the course of their ecological preferences. Depositional regime fluctuates between marginal marine to normal marine. A warm-humid climate prevails throughout the deposition, as indicated by the abundance of ferns, and other hygrophilous spores, and rare xerophytes.     

Oil hydrocarbon fingerprints of the different marine organisms in some Egyptian Gulf of Suez waters

Oil hydrocarbon fingerprints derived from polycyclic aromatic and aliphatic hydrocarbon were analyzed in marine organisms of various aquatic species muscles collected from 10 different sites along Suez Gulf, Egypt. All samples were analyzed for n-alkanes (C₁₅–C₃₇) and polycyclic aromatic hydrocarbons (EPA list of PAHs). n-Alkanes in ten aquatic species were found to be in the range of 11.391–96.747?ng/g wet weight with a mean value of 60.755?ng/g wet weights. Different indices were calculated for the n-alkanes to assess their sources as carbon preference index (CPI), average chain length (ACL), terrigenous/aquatic ratio (TAR), natural n-alkane ratio (NAR) and proxy ratio (Paq). Most of the various species of n-alkanes were discovered to be from natural sources. Polycyclic aromatic hydrocarbons (PAHs) varied between 81.499 and 5895.608?ng/g wet weight with an average of 2521.126?ng/g wet weight. The contents of ?PAHs were the highest in the tissues. The carcinogenic risks for humans from residual ?PAHs in the various fish tissues higher than10^?5.     

Petrophysical evaluation of clastic Upper Safa Member using well logging and core data in the Obaiyed field in the Western Desert of Egypt

Upper Safa Member is part of Jurassic Khatatba Formation; it consists of low net gross ratio sand streaks. The core and well logging data were used to perform a comprehensive reservoir evaluation. The Schlumberger application “Techlog” was used to perform the required evaluation analysis. Four oriented wells were selected for this study. The volume of shale “Vsh” using gamma-ray (GR) was used to evaluate the lithology and to discriminate sand “reservoir” from shale “non-reservoir”. A porosity model using the density log was constructed and used as an input to calculate Archie’s water saturation “Sw”. Porosity- Permeability (Poro-Perm) Transform was used to evaluate the reservoir permeability. The net reservoir and net pay thicknesses were seen attractive in three out of four wells. The reservoir quality parameters “Porosity and Permeability” were different from well to well. The hydrocarbon saturation “Sh” was high in the three wells. The hydrocarbon intervals depths were highlighted and considered in the perforation strategy.     

Utilizing the Rock-eval pyrolysis and biomarkers parameters to characterize the organic matters of selected wells in the Central Gulf of Suez,Egypt

Organic matters from the KK 85-1and HH 83-1wells in the Central Gulf of Suez were analyzed by two well-proven organic geochemical methods: Rock-Eval pyrolysis and gas chromatography–mass spectrometry (GC–MS) analyses. These techniques were used to obtain independent parameters of organic matter composition, thermal maturity, and environment of deposition. The study reveals a close concordance between Rock-Eval pyrolysis data and biomarkers parameters such as steranes and triterpanes. Rock-Eval pyrolysis in conjunction with GC–MS analyses shows that the organic matters contain two types of kerogen (Type-II/III and Type III), which lie dominantly prior to the peak stage of the conventional oil window (end of diagensis–beginning of catagensis). The case study shows that these methods are suitable for a proper assessment of the petroleum potential of source rocks and the rapid geochemical characterization of sedimentary organic matter.     

Geochemical characteristics of organic matter from Rudeis and Kareem source rocks,Ras Budran oilfield,central Gulf of Suez,Egypt

The organic matters of Rudeis and Kareem formation from Ras Budran oilfield in the central Gulf of Suez, Egypt, were investigated throughout the study of biomarkers and infrared spectrometric analyses. The results showed that Pr/Ph, Pr/n-C₁₇, and Ph/n-C₁₈ ratios indicated marine source organic matters deposited under reduced condition with a less effect of biodegradation and mature stage of occurrence. The gammacerane index indicated a low-salinity environment of deposition for the initial organic matters existed in the analyzed samples. Steranes distributions show high percentage of C₂₈ steranes and C₂₉ steranes compared with C₂₇ steranes, and low-concentration C₂₇ diasteranes show generally low ratios indicating anoxic carbonate source rocks. The diasteranes/steranes showed generally low ratios indicating most marine carbonate sources. The tricyclic terpane reflects mature organic matters and originated from marine organic sources.