Earth Science Research
ISSN / EISSN : 1927-0542 / 1927-0550
Current Publisher: Canadian Center of Science and Education (10.5539)
Total articles ≅ 214
Latest articles in this journal
Earth Science Research, Volume 10; doi:10.5539/esr.v10n2p33
The reservoir in different parts of buried-hill draping zone is often quite different, so it is of great significance to clarify the reservoir characteristics for exploration and development. Based on core, well logging, seismic data and production data, reservoir characteristics of oil layer Ⅱ in the lower second member of Dongying Formation of L oilfield, Bohai Bay Basin, offshore eastern China are systematically studied. Analyses of seismic facies, well-seismic combination, paleogeomorphology, and sedimentary characteristics are carried out. Sediment source supply, lake level and buried hill basement geomorphology all contribute to reservoir quality. The research suggests that the different parts of buried-hill draping zone can be divided into four types. Reservoir thickness and physical properties vary. The area where the provenance direction is consistent with the ancient valley direction is a favorable location for the development of high-quality reservoirs. Under the guidance of the results, oilfield production practices in L oilfield offshore China are successful. Knowledge gained from study of L oilfield has application to the development of other similar fields.
Earth Science Research, Volume 10; doi:10.5539/esr.v10n2p23
Previous work has tied the drag reduction properties of polymer solutions to type and concentration of salts, rather than its ionic strength, although it is a more extensive parameter to investigate the effects of salt contents on fluids behavior. The current study aims at investigating the relationship between ionic strength and drag reduction characteristics of polymer solutions when flowing in straight tubing. Nalco ASP-700 and ASP-820, two common anionic AMPS copolymers, are examined with various salts (2% KCl, 4% KCl, and synthetic seawater). Flow tests were conducted using a small-scale flow loop that includes a straight tubing with an outside diameter of 1.27 cm and a length of 4.57 m. It has been found that drag reduction performance of polymer solutions is well correlated with ionic strength, rather than salt type and/or concentration. With high ionic strength, lower drag reduction is noticed despite of the reduced salt concentration. Nevertheless, at higher Reynolds number, the effects of ionic strength minimizes. Both polymer solutions exhibit effective drag reduction characteristics and their behavior is greatly affected by polymer type, shear rate, and salt content. Correlations, with acceptable confidence level, between drag reduction ratio and solutions ionic strength are proposed. The correlations are strongly recommended to investigate the effects of salt types and/or concentrations, represented by its ionic strength on drag reduction behavior of polymer solutions in straight tubing.
Earth Science Research, Volume 10; doi:10.5539/esr.v10n2p1
Flooding is a natural phenomenon of the hydrological cycle, but it has become an urban concern in many cities around the world. Due to human intervention on the functioning of hydrosystems through infrastructure, the channelling of watercourses, the redirection of the flow and the inevitable extension of the urban landscape, floods have become a growing urban hazard. Several cities are currently facing very frequent flash floods. These floods are of various types and several factors are at the origin of their manifestation, which leaves its understanding and prevention for local stakeholders a long-term process that requires a colossal amount of work among several multidisciplinary researchers. Without denying the scientific consensus on the role of climate change, currently floods are largely caused by the senseless and irresponsible behaviour of humans. Among the cities in Saudi Arabia facing the risk of flooding is the city of Abha located in the southwest of the country, the focus of this research. It is subject to recurrent and devastating floods caused by several factors. Controversial topography, dissected orography, aggressive rainfall, accelerated and unregulated urban growth, and irresponsible human intervention are all factors that aggravate this problem. The resolution of this problem, or at least the minimization of its consequences, requires a rigorous and carefully studied approach. The appropriate knowledge by local stakeholders must be reinforced by a methodological and cartographic assessment of this phenomenon in order to mitigate its consequences. The main objective of this work is to make cartographic and methodological contributions to acquire additional knowledge on the flood hazard in the city of Abha through a statistical processing of rainfall data for the period 1978-2018, a mapping of the factors intervening on the runoff and its various behaviors and finally a synthetic analysis.
Earth Science Research, Volume 10; doi:10.5539/esr.v10n1p82
Reviewer Acknowledgements for Earth Science Research, Vol. 10, No. 1, 2021.
Earth Science Research, Volume 10; doi:10.5539/esr.v10n1p61
The lead-zinc-barium deposits of the southern Benue Trough, Nigeria belong to a suite of clastic dominated fracture filling hydrothermal vein deposits. The alteration types and spread are poorly known yet required to aid exploration. Band ratio composites (BRC), Principal Component Analysis (PCA), and Minimum Noise Fraction (MNF) were applied to a full scene Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery covering the study area. Spectral analysis of sulphide minerals known in the area led to the development of the (B1+B3)/2 ratio, which provided a highly effective sulphide discriminant. PCA and MNF bands with high eigenvectors in the absorption features of target minerals qualified as colour composite candidates for alteration mapping. This study demonstrated the effectiveness of combining the BRC, PCA and MNF techniques in the discrimination of ferric-ferrous/sulphide and silica alteration zones in the Southern Benue Trough.
Earth Science Research, Volume 10; doi:10.5539/esr.v10n1p49
The United States Supreme Court settled legal disputes concerning four different Larimer County (Colorado) locations where water is moved by gravity across the high elevation North Platte-South Platte River drainage divide, which begins as a triple drainage divide with the Colorado River at Thunder Mountain (on the east-west continental divide and near Colorado River headwaters) and proceeds in roughly a north and northeast direction across deep mountain passes and other low points (divide crossings) first as the Michigan River (in the North Platte watershed)-Cache la Poudre River (in the South Platte watershed) drainage divide and then as the Laramie River (in the North Platte watershed)-Cache la Poudre River drainage divide. The mountain passes and nearby valley and drainage route orientations and other unusual erosional features can be explained if enormous and prolonged volumes of south-oriented water moved along today’s north-oriented North Platte and Laramie River alignments into what must have been a rising mountain region to reach south-oriented Colorado River headwaters. Mountain uplift in time forced a flow reversal in the Laramie River valley while flow continued in a south direction along the North Platte River alignment only to be forced to flow around the Medicine Bow Mountains south end and then to flow northward in the Laramie River valley and later to be captured by headward erosion of the east-oriented Cache la Poudre River-Joe Wright Creek valley (aided by a steeper gradient and less resistant bedrock). Continued uplift next reversed flow on the North Platte River alignment to create drainage routes seen today. While explaining Larimer County North Platte-South Platte drainage divide area topographic map drainage system and erosional landform evidence this interpretation requires a completely different Cenozoic history than the geologic history geologists usually describe.
Earth Science Research, Volume 10; doi:10.5539/esr.v10n1p32
Relative contributions of common ingredients to heavy orographic rainfall associated with the passage of Hurricanes Hugo (1989) and Isabel (2003) over the Appalachian Mountains are examined using a numerical weather prediction model. It is found that the key ingredients for producing local heavy orographic rainfall were: high precipitation efficiency, strong low-level flow, strong orographically forced upward motion associated with strong low-level flow over relatively gentle upslope, concave geometry providing local areas of convergence, high moist flow upstream, a relatively large convective system associated with both tropical cyclones (TCs), and relatively slower movement. In addition, neither conditional instability nor potential (convective) instability is found to play essential roles in producing strong upward motion leading to heavy orographic TC rain. A modified Orographic Rain Index (ORI) is proposed as a predictor for heavy orographic TC precipitation, which includes the upstream incoming horizontal wind speed normal to the local orography, the steepness of the mountain, the relative humidity, the TC moving speed, and the horizontal scale of the TC. It is found that the ORI estimated in regions of local maximum rainfall by using fine-resolution numerically simulated results correlate well with rainfall rates for both hurricanes, indicating that it may serve as a predictor for heavy orographic TC rainfall.
Earth Science Research, Volume 10; doi:10.5539/esr.v10n1p8
The Miocene rocks of the Marádah Formation have been stratigraphically investigated from four stratigraphical sections around the Marádah Oasis in the Central Sirt Basin of Libya. The field investigations led to the identification of two members, the lower Qarat Jahannam Member and the upper Ar Ráhlah Member. Fourteen sedimentary facies at the outcrop-scale representing a gradual development of sedimentation from a continental clastic witness in the southwestern outcrops to transitional estuarine, lagoonal, and beaches to the proximal offshore in the northern outcrops, were recognized. The results indicates that the accumulation of the Marádah Formation is transgressive in nature and corresponding to two phases of deposition which have been mentioned in the earlier studies. The first phase is continental-dominated facies in which cross-bedded sandstones and calcareous sands comprise most of the depositional sequence of the lower Qarat Jahannam Member at the southwestern outcrops. This phase, however, is characterized by extremely bioturbated laminated-shale conquered by Skolithos ichnofacies in the lower part of the upper Ar Ráhlah Member at the northern outcrops. This phase is providing further evidence that the contact between the two members is diachronous everywhere in the study area. The clastic-phase has thought to be deposited in the Lower Miocene (Aquitanian-Burdigalian) since the lower Qarat Jahannam Member rests on an erosional surface of submarine origin in the southwestern outcrops above a 0.5 m. thick of a nummulitic unit of the Oligocene Bu Hashish Formation. The second phase is marine-dominated facies in which a bioclastic limestone unit rich in thick and disarticulated oysters, including Crassostrea gryphoides (Schlottheim), characterizes the sediments of the Ar Ráhlah Member at the southwestern outcrops. This phase also includes the upper part of the latter member at the northern outcrops in which a detrital limestone unit rich in turritelline gastropods is overlying by thick-bedded calcarenites rich in disarticulated oysters, gastropods, irregular echinoids (notably, Clypeaster and Echinolampas), bryozoans, and celestite corals. The upper part of the Ar Ráhlah Member at the northern outcrops, nevertheless, is terminated by a quite hard dolomitic limestone and by a pretty soft dolomitic marly limestone. Both lithologies, however, are combined with medium-sized oysters, including Ostrea digitalina Fuchs, and pectinid bivalves. The second phase, however, is interpreted to be deposited in the Middle Miocene (Langhian and Serravallian) based on the total-stratigraphic range of the larger benthic foraminifera Borelis melo melo (Fichtel & Moll), which recovered from the studied washed residues, and the associated microfacies.
Earth Science Research, Volume 10; doi:10.5539/esr.v10n1p1
The quick-look and gas chromatography analyses were used for formation evaluation of four depth intervals in a well (well A) located within the offshore of the Rio Del Rey basin. The results show 3 water reservoirs (R1 to R3) and 1 hydrocarbon reservoir (R4). The quick-look reveals that the hydrocarbon (oil and gas) reservoir is a shaley sandstone or a radioactive sandstone located between 4898-4932 Mmd which is filled by oil and gas and with a good porosity. The chromatographic gas ratio analysis reveals that the hydrocarbon reservoir is filled by a productive gas which may be a wet gas. The result provided by the gas chromatography is a false result probably due to its limitation which is that the hydrocarbon component must exist at the gaseous phase (C1-C5) to be detected and analyzed. The gas chromatography based its analysis only in the C1 to C5 range, in oil we have from C1 to C8.
Earth Science Research, Volume 9; doi:10.5539/esr.v9n2p85
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