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This work responds to what was reported in various audio-visual media channels and to queries and explanations from individuals and local residents on the causes of gaseous and thermal emissions from the Earth near the vicinity of the village of Al-Hindaw in Dakhla city, New Valley Governorate, Egypt. At the location of the fume exit area, magnetic, seismic, and electromagnetic geophysical investigations were carried out to identify the factor(s) responsible for the event in question. Rock samples were collected and studied geochemically and radiographically to assess their chemical compositions, as well as the quantity of organic chemicals that may have contributed to the burning and temperature increase. In light of the results of the geochemical and geophysical research, it is believed that the self-ignitions are the result of near-surface reactions and oxidation instead of volcanic activity, such as the presence of magma or other comparable phenomena. [ABSTRACT FROM AUTHOR]

The Middle Jurassic syn-rift sediments of the Khatatba Formation contain not only the principle source rock organofacies in the north Western Desert (NWD), but also several potential sandstone reservoir targets. However, controls on the reservoir quality of the Khatatba facies and spatiotemporal evolution of the reservoir rock types (RRTs) are still blurred. This study integrates seismic, wireline logs, and conventional core data from some wells in the Meleiha development lease in the NWD to investigate the petrophysical characteristics of the Khatatba reservoir facies, and determine the different RRTs. On seismic, Khatatba Formation consists of high reflectivity, continuous reflections displaying an upward decrease in seismic amplitude corresponding to a fining-upward clastic succession of fluvial–tidal facies. These facies display a large-scale pore system heterogeneity, thereby comprising three different RRTs. RRTI and RRTII rocks have a well-connected pore network dominated by capillary and super-capillary pores (> 10 µm), whereas sub-capillary pores (< 10 µm) are more common in RRTIII sediments. RRTI rocks consist of quartzose sandstones with a clean pore network (cement < 20%). The open pore system of RRTI allows a displacement of more than 80% of the pore water at entry pressure levels < 500 psi. Carbonate and clay components are more common in RRTIII rocks (average = 5.6% and 13%, respectively). These components adversely impact the pore system connectivity of RRTIII sediments. Fluvial channel sandstones host the principal fluid flow conduits where RRTI sandstones account for more than 95% of the reservoir flow capacity. The present study provides the first reservoir rock typing for the Khatatba clastic reservoir facies and highlights the link between depositional, compositional attributes and the spatial distribution of the different RRTs. [ABSTRACT FROM AUTHOR]

Western Desert represents a major oil and gas province in Egypt producing more than 50% of the country's oil production. Oil and gas blend occurs in most producing fields, however, the genetic link between gas and liquid hydrocarbon phases are not well-constrained. Obayied sub-basin in the Western Desert where oil and gas phases coexist in the Middle Jurassic sandstones of the Khatatba Formation provides an ideal place to investigate the link between oil and gas generation. Geochemical analyses on rock samples (Rock–Eval pyrolysis, vitrinite reflectance, Ro) and gases (molecular and isotopic composition) were conducted in order to identify the genetic characteristics of the hydrocarbon phases produced. Maturity-relevant parameters (Rock–Eval Tmax, vitrinite reflectance Ro) elucidate that only Middle Jurassic Khatatba organofacies capable of generating wet and dry hydrocarbon gases. Additionally, the enrichment of C7 normal alkanes, mono-branched alkanes relative to poly-branched components in the Obayied gases reflect their generation via cracking of oil. Basin modelling results confirm gas generation through both primary and secondary cracking. However, secondary cracking of liquid hydrocarbon phases is volumetrically more significant. Primary cracking of the Khatatba organofacies likely predate and catalyze the secondary cracking of the liquid phases and therefore the volume of generated gas increases incrementally eastward where both processes coexist. The present study highlights the significant role of secondary cracking in the generation and accumulation of huge gas accumulations in the basins containing oil-prone source intervals. [ABSTRACT FROM AUTHOR]

Mesozoic rift basins of the north Western Desert host the majority of proven oil reserves in Egypt. These basins are bounded by poorly-explored structural highs (Kattaniya high, Qattara ridge) with unknown petroleum system. The recently-discovered oil in West Wadi El-Rayan (WWER) concession in the southern part of the Kattaniya high highlighted a need for understanding the petroleum potential of these transit regions. The present study integrates geochemical and basin modelling results to define potential source rocks and decipher the mechanism of oil generation, expulsion and migration. In WWER concession, oil is produced from the Upper Cretaceous (Upper Bahariya) sandstones. Rock-Eval pyrolysis results demonstrate that the Lower Cretaceous Alam El Bueib (AEB) and Upper Cretaceous Lower Bahariya shales below the reservoir contain mature source rocks (S 2 up to 28.76, T max > 430 °C). WWER oil displays a uniform composition with high pristane/phytane (Pr/Ph > 3), saturates/aromatics (>5.5) and canonical variable values (CV > 6) pointing to a generation from a terrestrial source rock. This is consistent with high contents of C 30 hopane, C 29 steranes and diasteranes as well as the very low values of dibenzothiophane (DBT)/Phenantherane (<0.1) confirming oil generation from a clay-rich source rock deposited in a fluvio-deltaic environment. Oil-source correlation highlights a robust similarity in compositional biomarkers between the WWER oil and AEB rock extracts. Additionally, the maturity-relevant biomarkers such as Ts/Tm trisnorhopanes and H 32 S/(R + S) homohopanes favor an oil expulsion phase during the early stage of oil window in accordance with the basin modelling results and the maturity level of AEB organic-rich facies. These findings shed the light on a new petroleum system in the north Western Desert where the AEB fluvio-deltaic shales are capable of generating early mature oil which migrates through the Cretaceous deep-seated extensional faults into the Bahariya sandstone reservoir. • The origin of oil trapped in the poorly-explored Kattaniya high has been evaluated. • Oil-source correlation typifies oil generation from Lower Cretaceous source. • Oil was sourced from Alam El Bueib (AEB) organofacies. • Oil expulsion took place during the early oil window. • A new petroleum system within the Cretaceous succession has been proposed. [ABSTRACT FROM AUTHOR]

The Early Cretaceous late syn-rift sediments of Alam El Bueib Formation host potential, however poorly-explored reservoir targets in the north Western Desert of Egypt. The controls on depositional evolution and architecture of Alam El Bueib sedimentary facies, as well as the influence of depositional attributes on reservoir facies heterogeneity, are poorly constrained. Therefore, this study integrates seismic, sedimentological, and petrophysical data from Meleiha concession in the north Western Desert to build evolutionary models for Alam El Bueib succession and predict the architecture of the potential reservoir facies. Several channel systems were observed with a notable upward transition from complex-filled to flat-filled channels. The complex-filled channels correspond to the early highstand tidally-influenced estuarine, deltaic/estuarine sediments of Alam El Bueib-IV and Alam El Bueib-IIIG units. Matruh canyon and Alam El Bueib-IIIG fluvial sand bars were developed during a phase of forced regression, and the canyon was infilled by hemiplegic mudstones during the Late Valanginian sea level rise. The late highstand and lowstand facies of Alam El Bueib-IIIG unit present the main fluid flow conduits. The minimal degree of reservoir heterogeneity occurs in the lowstand amalgamated fluvial sandstone bars, whereas lateral and vertical reservoir heterogeneity increases in the deltaic/estuarine and estuarine successions of Alam El Bueib-IIIG and Alam El Bueib-IV, respectively. The lateral compartmentalization of the Alam El Bueib-IIIG fluvial facies against Alam El Bueib Matruh canyon shales produced excellent stratigraphic traps that should be tracked throughout the entire north Western Desert. • Seismic and sedimentary facies of AEB Formation have been studied. • Several channel-fill seismic facies were recognized. • The channel geometry and infill characteristics vary with sequence stratigraphic framework. • Amalgamated fluvial sand bars of AEB-IIIG unit contain the main fluid-flow conduits. • The shale-infill of the regressive Matruh Canyon played an important role in hydrocarbon entrapment. [ABSTRACT FROM AUTHOR]