Origin of Bahariya oil in Salam oil field,Western Desert- Egypt

The origin of Bahariya oil is a debatable issue. Bahariya Formation produces oil from the Lower sandstone unit by normal pressure mechanism, while the Upper Bahariya shale produces oil by fracking mechanism. The main question is: is there any genetic relationship between the two oils.To answer this question, “50” ditch samples, “12” extract samples and “2” oil samples represent Khatatba and Bahariya formations and Abu Roash ‘G’ Member, collected from six wells drilled in Salam oil field, have been geochemicaly analyzed, using LECO SC632, Rock–Eval- 6 pyrolysis, GC and GC/MS techniques.The analysis shows that the Total Organic Carbon content (TOC) for the studied formations ranges from fair to v.good, with poor to good hydrocarbon potentiality. The maturity evaluation using Tmax, and calculated Vitrinite reflectance (R_o) showed that the studied samples have good thermal maturation reaching the stage of oil generation. Also the analysis revealed that the kerogen is a mixture of type II/III kerogen, reflecting the potential generation of oil and gas. The GC and GC/MS data showed that the organic matter is a mixed marine/terrestrial input deposited in transitional environment under prevailing reducing conditions. The oil samples fingerprint of the saturated hydrocarbons fraction from Baharyia reservoir (Lower and Upper) members suggest that the oil samples have a mixed organic source with significant terrestrial organic matter input deposited under saline to hypersaline environment with slightly oxidizing environment.Based on the obtained results, it is suggested that the Bahariya oil has been sourced mainly from deeper horizons (Khatatba Formation) with some contribution from upper and lower Bahariya source rocks.     

Analysis and interpretation of aeromagnetic data for Wadi Zeidun area,Central Eastern Desert,Egypt

The current study is mainly concerned with the analysis and interpretation of the available aeromagnetic data using different advanced processing techniques, to map the subsurface structural framework and depth estimation of these structures of the Wadi Zeidun area, Central Eastern Desert. The visual inspection of the RTP aeromagnetic map defines a rapid change in the subsurface geologic conditions in the form of the lithological characters and tectonic inferences. The shallow sources can be separated from those of deeper causatives, using power spectrum transformation tool. Two methods for locating magnetic sources, Source Parameter Image and Analytical Signal to identifying the properties of their sources indicated that, the depth calculation from the used tools ranges between 900 and 3000 m as the average ranges. Also, the comparative study among the 2D magnetic modelling was established by two profiles constructing. The mapped basement tectonic map is affected by a set of faults trending mainly in the N-S, NE-SW, NW-SE and ENE-WSW direction.     

Source rock evaluation and organic geochemistry of Belayim Marine Oil Field,Gulf of Suez,Egypt

Geochemical evaluation of Belayim Marine Oil Field using TOC and Rock Eval Pyrolysis investigations for a total of 19 cutting samples (9 samples covering (Nubia-B Formation) from well BM-57, and 10 samples covering (Nubia-A, B Formations) from well BM-65) was performed. Furthermore, geochemistry analyses of two crude oil samples from Wells BM-29 and BM-70, which are recovered from the Upper Rudeis Formation were performed. The BM-70 oil sample is recovered by Drill Steam Testing, while the BM-29 oil sample is taken from the flow output. Moreover, the oil samples were subjected to GC/GC-MS analysis (Biomarker) by StratoChem Company.In general, TOC analyses showed that the Nubia-A and B formation sediments are fairly immature compared to good source rocks with very high Hydrogen Index indicative of kerogen type II. The geochemical investigations of two oil samples indicate that the Upper Rudeis oil of Belayim Marine was derived from a marine carbonate rich source, which is relatively rich in algal organic matter and has moderate sulfur content. The maturity of the analyzed oils (about 0.75% R0) falls short from the stage of peak hydrocarbon generation which is known to be reached at about 0.85% R0.     

煤系烃源岩油气生成、排出与滞留特征

针对煤系地层烃源岩的油气生成、排出与滞留能力的有效性问题,选取不同沉积环境、不同时代煤岩及其夹层中的碳质泥岩和泥岩,开展了在成岩作用下的高温高压半开放—半封闭体系模拟实验,建立了相应的演化模式。结果表明,不同沉积环境下,Ⅱ₂型煤系烃源岩在生油窗内具有一定的排油能力,也具备较强的烃气生成能力,既可以作为油源岩,也是高效气源岩;而Ⅲ型煤系烃源岩在生油窗内主要以滞留油为主,基本不具备排油能力,主要以排出烃气为主,仅能作为气源岩。生烃转化率主要受控于有机质类型,排烃能力还受控于岩性与丰度,按单位质量岩石而论,煤岩远高于其夹层中的碳质泥岩与泥岩。煤岩在全演化阶段,无论是低阶煤还是高阶煤均具有较强的生成烃气能力和较高的滞留油气能力,都具有煤层气开发潜力。     

The impact of seismic interpretation on the hydrocarbon trapping at Falak field,Meleiha, Western Desert,Egypt

The object from this study is to find ways to develop field and discover the possible reservoirs and appropriate solutions to avoid the problems we have faced before in the drilled wells that led to drilling dry wells close to producing wells. A set of twenty reflection sections have been used to highlight the subsurface structural setting and the hydrocarbons entrapment styles in Falak field in the northern Western Desert, this is achieved through an integrated geological and geophysical studies utilizing a number of maps and cross sections, all of that for demonstrating all the chances for exploring or developing the field. The reflectors are Ras-Qattara formation, Khatatba-2D member, Masajid formation, Alam El Beuib 3G member, AEB 3F member, AEB 3E member, AEB 3D member, AEB 2A member, AEB 1 member, Alamein Dolomite formation, Dahab Shale member, Kharita formation, Bahariya 5 member, Bahariya 4 member, Bahariya 1 member, Abu Roash “G” member, Abu Roash “E” member, Abu Roash “A” member, and the Apollonia formation. The N-S and E-W trending seismic sections revealed normal faults forming shape seems to be horsts all over the mapped field, these faults led to thin Cretaceous section in the up thrown block area compared to thick section on the downthrown block of the two main faults, for some instances dry hole conditions occur due to missing of structural closure on both the up thrown block and the downthrown. The TWT maps on the top of the traced reflectors reveal different structural closures with set of normal faults constructing three way dip closure in most of these faults and big shape like horst.     

Evaluation of petroleum hydrocarbons and its impact on organic matters of living organisms in the northwestern Gulf of Suez,Egypt

Abstract

The levels of Total Petroleum Hydrocarbons (TPH) have been reported for ten commercially important fish species from the northwestern Gulf of Suez, Egypt. Target compounds were analytically determined with gas chromatography–flame ionization detector and High-performance liquid chromatography analysis. Results showed that total petroleum hydrocarbon varied from 21700 to 1503100?ng/g wet wt., Argyrops Spinifer showed the highest level of TPH in the muscle tissue followed by Euthynnus affinis 1459800?ng/g wet wt. These data are very important for coming pollution monitoring program to the Suez Gulf. Polycyclic aromatic hydrocarbons (16 PAHs) varied between 81.499 and 5895.608?ng/g wet wt. The diagnostic indices used showed that the hydrocarbons in the area were from both biogenic and anthropogenic sources. Hence, there is need for adequate regulation and control of all activities contributing to the levels of petroleum hydrocarbon in the marine environment for the safety of human, and fish species lives in the area.     

Burial and thermal history simulation of the subsurface Paleozoic source rocks in Faghur basin,north Western Desert,Egypt: Implication for hydrocarbon generation and expulsion history

Paleozoic Zeitoun, Desouqy and Dhiffah formations represent source rocks to hydrocarbon in Faghur basin, north Western Desert, Egypt. They are characterized by a sufficient amount of organic matter belonging to kerogen type III and mixed type II/III, which are in maturation stage. A 1D-basin modeling was performed by using geological and geochemical data of the Paleozoic source rocks from five wells in Faghur basin, north Western Desert, Egypt. These data used in 1D basin modeling for constructing and understanding of burial and thermal geo-histories of Faghur basin and for simulating and predicting the timing of petroleum and expulsion for the Paleozoic source rocks in the studied wells. Burial and thermal history models indicate that the Zeitoun Formation entered onset of oil generation in the studied wells during Late Cretaceous (100.10–91.65 my) with transformation ratio (TR) 10–25, peak oil during Late Cretaceous (91.65–79.30 my) with TR 25–50 and late oil stage at Late Cretaceous (79.30 my-0) to present day with TR 50–60.45. Desouqy Formation entered onset of oil generation also during Late Cretaceous (94.43–73.60 my) with TR 10–25 in the studied wells, peak oil during Late cretaceous (73.60–62.40 my) with TR 25–50 and Late oil stage during Late Cretaceous to present day (62.40 my-0) with TR 50–61.82. Dhiffah Formation entered onset of oil generation in the studied wells during Early to Late Cretaceous (102.11–92.27 my) with TR 10–25, peak oil during Late Cretaceous (92.27–86.40 my) with TR 25–50 and late oil stage at Late Cretaceous to present day (86.40 my-0) with TR 50–67.27. No cracking oil to gas in the studied Paleozoic source rocks in the studied wells. These basin modeling results also suggest that the Paleozoic source rocks act as an effective source rock where a significant amount of petroleum is expected to be generated and expelled to any nearby prospect reservoir rocks in the Faghur basin.     

The Petrography,Mineralogy, and Hydrocarbon Potential of the Shales of the Duwi Formation,Abu Tartur,South Western Desert,Egypt

Abstract

Eight shale samples related to the Duwi Formation (Campanian-Maastrichtian) of the Abu Tartur mines of the southwestern desert of Egypt were petrographically, mineralogically, and geochemically studied. The study results indicate that the detrital material of these shales were derived mainly from mafic to ultramafic components of the basement rocks under intensive chemical weathering and deposited in an alkaline reducing marine environment of low energy and these shales do not attain the requirements of hydrocarbon production.     

Oil:Oil Correlation for Some Oil Fields in the North Western Part of the Western Desert,Egypt

Abstract

Physical and specific geochemical analyses are used in detail for the petroleum geochemical studies to permit the correlation of six crude oil samples from Western Desert Egypt. Different analytical techniques, including liquid chromatographic separation, gas chromatography, and gas chromatography-mass spectrometry (GC-MS), were used to characterize the oil samples. The oils were identified using oil characterization parameters including specific gravity (°API), sulfur content, distribution of n-alkanes, carbon preference index (CPI), pristane/phytane ratio, isoprenoid/n-alkane ratios, and detailed biological marker analysis. All these parameters showed that the studied oil samples are correlated with each other, where they are similar in their oil type maturation and source depositional environments.     

Oil:Oil Correlation for Some Oil Fields in the North Western Part of the Western Desert, Egypt

Physical and specific geochemical analyses are used in detail for the petroleum geochemical studies to permit the correlation of six crude oil samples from Western Desert Egypt. Different analytical techniques, including liquid chromatographic separation, gas chromatography, and gas chromatography-mass spectrometry (GC-MS), were used to characterize the oil samples. The oils were identified using oil characterization parameters including specific gravity (°API), sulfur content, distribution of n-alkanes, carbon preference index (CPI), pristane/phytane ratio, isoprenoid/n-alkane ratios, and detailed biological marker analysis. All these parameters showed that the studied oil samples are correlated with each other, where they are similar in their oil type maturation and source depositional environments.     

Evaluation of possible source rocks and extracts characteristics from Safir-1x well,North Western Desert,Egypt

The pyrolysis and vitrinite reflectance estimations for fifteen shale rock tests and additionally, geochemical burial history, and gas chromatography – mass spectrometry parameters were talked about to explore the hydrocarbon generation and maturation level and time, type of hydrocarbon produced of rock units of Safir-1x well. The results assign that the Bahariya Formation is poor to great source rock to create oil and gas, with a lower thermal maturation degree than the Khatatba and Alam El Bueib formation. Alam El Bueib is viewed as good to excellent source rock for oil and gas age, having marginally high level of thermal maturation at oil window at around 40 million years. Khatatba formation achieved the oil and gas generation window at about 80 and 50 million years separately and considered excellent source rock.

The molecular gas chromatography and mass spectrometry parameters demonstrated that the extracts of source rocks reflected that the Bahariya and Alam El Bueib extracts have a mixed sources formed under transitional conditions at low grad of thermal maturation. Khatatba source rock extracts originated from marine sources formed under reducing conditions at high grade of maturation.     

Source rock evaluation of some upper and lower Cretaceous sequences,West Beni Suef Concession,Western Desert,Egypt

West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150 km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro), and well log data of some Cretaceous sequences including Abu Roash (E, F and G members), Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history and calculate the levels of thermal maturity of the Fayoum-1X well based on calibration of measured %Ro and T_max against calculated %Ro model. The calculated Total Organic Carbon (TOC) content from well log data compared with the measured TOC from the Rock-Eval pyrolysis in Fayoum-1X well is shown to match against the shale source rock but gives high values against the limestone source rock. For that, a new model is derived from well log data to calculate accurately the TOC content against the limestone source rock in the study area. The organic matter existing in Abu Roash (F member) is fair to excellent and capable of generating a significant amount of hydrocarbons (oil prone) produced from (mixed type I/II) kerogen. The generation potential of kerogen in Abu Roash (E and G members) and Betty formations is ranging from poor to fair, and generating hydrocarbons of oil and gas prone (mixed type II/III) kerogen. Eventually, kerogen (type III) of Kharita Formation has poor to very good generation potential and mainly produces gas. Thermal maturation of the measured %Ro, calculated %Ro model, T_max and Production index (PI) indicates that Abu Roash (F member) exciting in the onset of oil generation, whereas Abu Roash (E and G members), Kharita and Betty formations entered the peak of oil generation.     

东海盆地西湖凹陷古近系煤的生烃动力学

通过高温高压封闭体系条件下的热模拟实验和生烃动力学模拟分析,获得了西湖凹陷古近系平湖组和花港组煤生成气态烃的产率及其动力学参数。结合古地温演化史和热演化史恢复了西湖凹陷西部斜坡带、西次凹及中央构造带的古近系平湖组和花港组煤的生烃演化历史,并基于预测的镜质体反射率(R_o)建立了研究区煤的生气演化模式。研究结果表明,西湖凹陷煤所生成的天然气以甲烷(C₁)为主,重烃气(C₂—C₅)较少,C₁和总气态烃(C₁—C₅)的产率增长速率在煤的高成熟阶段(1.10%≤R_o<2.20%)最大,在成熟阶段(0.50%≤R_o<1.10%)次之,在过成熟阶段(R_o≥2.20%)最小,且含碳原子个数不同的重烃气(C₂、C₃、C₄和C₅)的主裂解期不同。在西湖凹陷煤的生烃演化过程中,西部斜坡带平湖组...     

东海盆地西湖凹陷古近系煤的生烃动力学

通过高温高压封闭体系条件下的热模拟实验和生烃动力学模拟分析,获得了西湖凹陷古近系平湖组和花港组煤生成气态烃的产率及其动力学参数。结合古地温演化史和热演化史恢复了西湖凹陷西部斜坡带、西次凹及中央构造带的古近系平湖组和花港组煤的生烃演化历史,并基于预测的镜质体反射率（R_o）建立了研究区煤的生气演化模式。研究结果表明,西湖凹陷煤所生成的天然气以甲烷（C₁）为主,重烃气（C₂—C₅）较少,C₁和总气态烃（C₁—C₅）的产率增长速率在煤的高成熟阶段（1.10%≤R_o<2.20%）最大,在成熟阶段（0.50%≤R_o<1.10%）次之,在过成熟阶段（R_o≥2.20%）最小,且含碳原子个数不同的重烃气（C₂、C₃、C₄和C₅）的主裂解期不同。在西湖凹陷煤的生烃演化过程中,西部斜坡带平湖组和花港组中的煤所生成的气态烃最少,生烃条件最差;而西次凹、中央构造带平湖组和花港组中煤所生成的气态烃较多,是比较有利的生烃区。花港组中煤生成气态烃的产率远小于平湖组,且至今尚未达到生烃高峰。     

塔里木盆地沥青生烃特征与生烃潜力

通过沥青砂岩与重质油热模拟实验方法,对塔里木盆地下古生界广泛赋存的沥青生烃特征与生烃潜力进行探讨.热模拟实验结果显示,沥青与重质油在热作用下均能生成烃类,表现出烃类裂解特征,生烃过程中既有气态烃也有液态烃生成;沥青砂岩样品、重质油样品与低成熟度一般品质的海相烃源岩生烃潜力大体相当.塔里木盆地下古生界存在沥青生烃证据,但实际成藏贡献尚需进一步油气地球化学证据支持.     

Source rock evaluation of Kharita and Bahariya formations in some wells,North Western Desert,Egypt: Visual palynofacies and organic geochemical approaches

Palynofacies analyses were applied on ninety-one samples from the subsurface Albian – Cenomanian succession represented by Kharita and Bahariya formations, encountered in El-Noor, and South Sallum wells, located in the North Western Desert, Egypt, to visually characterize the content of dispersed organic matter, as well as, organic geochemical characterization to reveal the depositional paleoenvironments and source rock potentiality. The result recognized of five palynofacies associations in the studied interval. The deposition of Kharita Formation took place mainly in a steady and a relatively stable deltaic to marginal environment continued as well in the lower part of Bahariya Formation with minor changes. The marine influence became more common in the upper part of Bahariya Formation showing the exceptional high hydrocarbon potential recorded in the studied interval. This indicates marine transgression by the end of the early Cenomanian (Upper Bahariya) age. Samples from the Kharita Formation contain abundant brown phytoclasts which suggest gas-prone kerogen type III and IV. While Bahariya Formation includes translucent, brown cuticles and woody tracheid phytoclasts pointing to more promising gas-prone kerogen type III. The organic geochemical analysis shows poor to fair gas-prone source rock potential within the study section., Thermally, the color of the spore grains in Kharita and Bahariya formations show that dark yellow to orange, indicates immature besides their general little poor hydrocarbon generation potentiality.     

Bulk Geochemical Characteristics of Crude Oils From Wells in the North Western Desert,Egypt

Abstract

Different oil samples were collected from oil fields in the North Western Desert; namely, Meleiha, Razaak, and North Qarun fields. These oils were analyzed geochemically, including sulfur content, American Petroleum Institute (API) gravity, and gas chromatography The results showed that API gravity and sulfur content indicate that the crude oils have high mature level of marine origin. Distribution of n-alkanes (Carbon Preference Index [CPI], pr/ph, and isoprenoide/n-alkanes ratios) reflects that the oil samples originated mainly from marine organic sources deposited in a reducing environment. This indicates that the oil samples under investigation are well correlated with each other in the western part of the North Western Desert.     

超压环境有机质热演化和生烃作用机理

通过对多个盆地大量样品的多参数对比分析,建立了超压抑制有机质热演化的多参数识别标志,揭示了不同成熟度指标对超压的差异响应.识别出超压抑制有机质热演化和生烃作用的4个层次:①超压抑制了有机质热演化的各个方面,包括不同干酪根组分的热降解(生烃作用)和烃类的热演化;②超压仅抑制了烃类的热演化和富氢干酪根组分的热降解,而对贫氢干酪根组分的热演化不产生重要影响,因此镜质体反射率未受到抑制;③超压抑制了烃类的热裂解,而对干酪根的热降解未产生明显影响;④超压对有机质热演化的各个方面均未产生可识别的影响.超压对有机质热演化的抑制作用层次取决于超压发育后有机质热演化反应的体积膨胀效应、产物浓度变化速率及超压的发育特征.早期强超压和长期保持封闭流体系统是产生第一层次超压抑制作用的必要条件.超压发育过晚、超压强度低、超压流体频繁释放等都可能导致超压对有机质热演化的各个方面均不产生可识别的影响.     

Crude Oil Geochemistry and Its Relation to the Potential Source Beds for Some Meleiha Oil Fields in the North Western Desert, Egypt

The results of the geochemical evaluation for eleven crude oil samples from some Meleiha oil fields revealed that, these oils have high specific gravity (°API), low sulfur content and rich in saturated hydrocarbons. Two oil classes were recognized. The first is carbonate oils of high maturity level, originated from marine origin. The second, deltaic oils of moderately level of maturation, derived mainly from terrigenous sources. Oil: source correlation for the productive oils and the extracts of the potential source beds revealed a genetic close relationship between oils and extracts of Khatatba and Alam El Bueib formations. This indicates that the source of the oils in the study area may be related to mixed sources of these formations.