S2 Values Research Articles

Palynofacies analysis and source rock evaluation of the Upper Cretaceous-Oligocene succession in the Drazia-1 well, Alamein Basin, Egypt

Visual palynofacies analysis and petroleum source rock assessment are reliable and widely used applications for hydrocarbon potential. The Alamein Basin located in the north Western Desert is one of the promising hydrocarbon provinces all over Egypt. In this context, a total of 59 cutting samples representing the Upper Cretaceous Khoman formation and the Paleocene-Oligocene Apollonia and Dabaa rock units from the Drazia-1 well drilled in the East Yidma Oil Field, Alamein Basin, were analyzed. These samples were investigated for their palynological and palynofacies microscopy, including 39 samples for geochemical screening of their organic carbon content and 10 samples for Rock-Eval® 6 Turbo. Palynofacies analysis defined two palynofacies types of organic matter (OM). The first was characterized by phytoclasts-AOM composition of kerogen type III (gas-prone) and represents the Dabaa and Apollonia formations, and was deposited in a highly proximal shelf setting in marginal oxic-dysoxic conditions. The second was dominated by amorphous organic matter (AOM) and recognized in the Khoman formation, demonstrating a distal suboxic-anoxic basin with oil-prone kerogen type II. Moreover, geochemical analyses of the total organic carbon (TOC) content and the Rock-Eval pyrolysis determine the characteristics of possible source rock intervals and defined their hydrocarbon potentials. The investigated interval (4200–5150 ft) is suggested to be a poor source rock due to poor hydrocarbon potential of S2 values. The organic matter was thermally immature of kerogen type III (woody material typically generates gas). The palynofacies distributions and thermal hydrocarbon maturation in the Alamien Basin were affected by the tectonic movements that happened in the northern Egypt, mainly the Syrian Arc System.

Hydrocarbon generation potential of coal measure source rocks from lower Permian Shanxi Formation in the central-eastern Ordos Basin, China: control from sedimentary facies

Source rocks of Shanxi Formation widely distributed in the Ordos Basin were deposited in different sedimentary facies. Different sedimentary facies differ in sedimentary environment and could have great impact on the accumulation of organic matters. TOC content and S1+S2 values of shale and coal samples from different sedimentary sub-facies of Shan 1 and Shan 2 sections of Shanxi Formation were measured to investigate the influence of sedimentary facies on organic geochemistry characteristics. The results showed that the average TOC content of shale samples from the pro-delta sub-facies of Shan 1 section was higher than other sub-facies and the shale samples from the shore shallow lake sub-facies of Shan 2 section had higher TOC content when compared with other three sub-facies. Compared with Shan 1 section, the Shan 2 section was richer in organic matter. And the hydrocarbon generation potential of source rocks from Shan 2 section was better than that of Shan 1 section. More than 50% of shale samples from the Shan 2 section was of fair to good hydrocarbon generation potential. This study could provide a framework for the identification of potential areas for conventional and unconventional petroleum exploration.

Broadband Dynamics of Ubiquitin by Anionic and Cationic Nanoparticle Assisted NMR Spin Relaxation.

The quantitative and comprehensive description of the internal dynamics of proteins is critical for understanding their function. Nanoparticle-assisted 15 N NMR spin relaxation spectroscopy is a new method for the observation of picosecond to microsecond dynamics of proteins when transiently interacting with the surface of the nanoparticles (NPs). The method is applied here to the protein ubiquitin in the presence of anionic and cationic silica NPs (SNPs) of different sizes. The backbone dynamics profiles are reproducible and strikingly similar to each other, indicating that specific protein-SNP interactions are unimportant. The dynamics profiles closely match the sub-nanosecond dynamics S2 values observed by model-free analysis of standard 15 N relaxation of ubiquitin in free solution, indicating that the bulk of the ubiquitin backbone dynamics in solution is confined to sub-nanosecond timescales and, hence, it is dynamically more restrained than previous NMR studies have suggested.

Broadband Dynamics of Ubiquitin by Anionic and Cationic Nanoparticle Assisted NMR Spin Relaxation

AbstractThe quantitative and comprehensive description of the internal dynamics of proteins is critical for understanding their function. Nanoparticle‐assisted 15N NMR spin relaxation spectroscopy is a new method for the observation of picosecond to microsecond dynamics of proteins when transiently interacting with the surface of the nanoparticles (NPs). The method is applied here to the protein ubiquitin in the presence of anionic and cationic silica NPs (SNPs) of different sizes. The backbone dynamics profiles are reproducible and strikingly similar to each other, indicating that specific protein–SNP interactions are unimportant. The dynamics profiles closely match the sub‐nanosecond dynamics S2 values observed by model‐free analysis of standard 15N relaxation of ubiquitin in free solution, indicating that the bulk of the ubiquitin backbone dynamics in solution is confined to sub‐nanosecond timescales and, hence, it is dynamically more restrained than previous NMR studies have suggested.

A Database Retrieval Method for the Prediction of Reduced Luminance Coefficient Tables of A Road Surface Based on Measurements in Situ

ABSTRACT The in-situ measurements for r-tables have attracted special attention owing to their advantages, including increased speed, simplicity of use, and nondestructive road effects. This study presents a database retrieval method proposed for the construction of a full-scale r-table from an r-table database with 25 r coefficients used as input parameters. The proposed method was used in an in-situ, r-table measurement device as a data processing algorithm. To evaluate the accuracy of the proposed method, we performed a) a table-to-table comparison of Q0, S1, and r-tables constructed by different methods and b) comparisons of calculated luminance values (Lave, U0, Ul ) for a typical road-lighting scenario based on the use of different r-tables. The table-to-table comparison results indicate that following the application of the proposed method, its calculated Q0, S1, and r-table values were very close to their actual values (EQ0 = 2.1%, ES1 = 5.0%, Error = 2.3%). Moreover, the proposed method also exhibits an improved luminance response and achieves a 2.1% difference in Lave , a 3% difference in U0 , and a 1.8% difference in Ul . This study proves that the proposed database retrieval method improves the model prediction accuracy.

Sedimentology and geochemistry of Cretaceous source rocks from the Tiancao Sag, Yin'e Basin, North China: Implications for the enrichment mechanism of organic matters in small lacustrine rift basins

Petrography and compositions of organic matters of Cretaceous source rocks from the Tiancao Sag, the Yin'e Basin, Northern China, have been presented in order to determine the Cretaceous sedimentary environment and processes that enriched organic matters. The mudstones of the Bayangobi Formation have medium–high total organic carbon (TOC) (0.27–2.59%) and S1 + S2 (0.30–12.23 mg HC/g rock) values. Vertically, three sedimentary units (2460–2600 m; 2640–2860 m; and 3020–3050 m) present good hydrocarbon potentials. The macerals, the C27-C29 regular sterane distribution, and the isotopic and element geochemistry of the kerogen prove that the organic matter has a mixed origin of plankton/algae and terrestrial plants. The vitrinite reflectance, Tmax, and biomarker parameters collectively suggest that the source rocks have reached the mature stage. The mudstones were deposited in a reducing brackish-saline environment, and the salinity-sensitive proxies indicate a gradual evolution of the sedimentary conditions from low to high salinity. The positive correlation between the hydrogen index value and TOC content and the negative correlation between Pr/Ph ratio and TOC content suggest that the primary productivity and preservation in reducing water collectively contributed to organic matter enrichment of the Bayangobi Formation. The relationship between sedimentation rate and TOC content suggests that a sedimentation rate of 60–70 m/Myr is conducive to the formation of effective source rocks. Therefore, the organic matter enrichment of Bayangobi Formation was controlled by moderate-high paleoproductivity, reducing conditions, and an appropriate sedimentation rate. This paper proposes a “supply-preservation-dilution” model for the source rocks in the Tiaocao Sag, Yin’e Basin.

The influence of the rib cage on the static and dynamic stability responses of the scoliotic spine

The thoracic cage plays an important role in maintaining the stability of the thoracolumbar spine. In this study, the influence of a rib cage on static and dynamic responses in normal and scoliotic spines was investigated. Four spinal finite element (FE) models (T1–S), representing a normal spine with rib cage (N1), normal spine without rib cage (N2), a scoliotic spine with rib cage (S1) and a scoliotic spine without rib cage (S2), were established based on computed tomography (CT) images, and static, modal, and steady-state analyses were conducted. In S2, the Von Mises stress (VMS) was clearly decreased compared to S1 for four bending loadings. N2 and N1 showed a similar VMS to each other, and there was a significant increase in axial compression in N2 and S2 compared to N1 and S1, respectively. The U magnitude values of N2 and S2 were higher than in N1 and S1 for five loadings, respectively. The resonant frequencies of N2 and S2 were lower than those in N1 and S1, respectively. In steady-state analysis, maximum amplitudes of vibration for N2 and S2 were significantly larger than N1 and S1, respectively. This study has revealed that the rib cage improves spinal stability in vibrating environments and contributes to stability in scoliotic spines under static and dynamic loadings.

The Sedimentary Evolution During Late Triassic‐Jurassic Period and the Hydrocarbon Exploration Direction in the Eastern Part of the Qiangtang Basin, Tibet

AbstractBased on the field outcrops surveyed, combined with recent published the regional tectonic evolution and geochronology data, we analyzed the lithologies and rock associations of strata, identified the sedimentary facies types, and discussed the distribution sedimentary facies and the hydrocarbon accumulation in the eastern Qiangtang basin during the Late Triassic – Jurassic. Marked by regional unconformities, there are two tectono‐stratigraphic units (from the Carnian to the Norian and from the Rhaetian to the Kimmeridgian, respectively) in the eastern part of Qiangtang basin. We systematically described the distribution range, thickness variation and lithological characteristics of different formations in the tectono‐stratigraphic units. The Late Triassic‐Jurassic is dominated by marine facies and marine ‐ continental transitional facies. The marine ‐ continental transitional facies include deltaic and tidal‐lagoon facies. Marine facies including gentle carbonate slope, evaporative platform, restricted platform, littoral, neritic, bathyal and abysmal facies. The Carnian stage is dominated by littoral–neritic–bathyal–abysmal facies in the north Qiangtang depression otherwise the littoral–neritic facies in the south Qiangtang depression. The early Norian stage is dominated by carbonate gentle slope‐mixed continental shelf facies. The late Norian, Bajocian, Callovian and Kimmeridgian stage are dominated by tidal flat‐delta facies in the north Qiangtang depression and littoral‐neritic facies in the south Qiangtang depression. The Bathonian and Oxfordian stage are dominated by evaporative platform‐ restricted platform‐ mixed continental shelf facies. The sedimentary facies formed zones from north to south and extended in an E–W direction. The Eastern Lower Uplift (ELU) played an important role in the division zones of sedimentary facies from north to south. During the Bathonian and Oxfordian, the ELU developed below the sea level and controlled the distribution of restricted platform, evaporative platform and platform margin. We analyzed 20 source rock samples from the upper Triassic‐Jurassic. The total organic carbon (TOC) value from Qoimaco, Buqu and Adula Formations. of late Triassic‐Jurassic in the eastern Qiangtang basin are ranges from 0.17∼0.33% (average 0.28%), 0.05∼0.25% (average 0.15%) and 10.32∼28.78% (average 19.33%), respectively. Obviously, the Adula Fm. developed good source rocks. The values of Tmax and S1+S2 in the Adula formation are 459–461°C (average 460°C) and 6.75‐28.55 mg/g (average 18.18mg/g), indicating that the Adula source rock has reached high‐over‐maturity stage. The bathyal, gentle slop and platform facie belts of the Upper Triassic can configurate the good hydrocarbon prospects in the northeastern area of the Qiangtang basin.

Evaluation of Shale Source Rocks and Clay Mineral Diagenesis in the Permian Basin, USA: Inferences on Basin Thermal Maturity and Source Rock Potential

The use of mineral diagenetic indices and organic matter maturity is useful for reconstructing the evolution of sedimentary basins and critical assessments for potential source rocks for petroleum exploration. In this study, the relationship of clay mineral diagenesis and organic matter thermal indices (Rock-Eval Tmax) and calculated vitrinite reflectance (%Ro) were used to constrain the maximum burial depths and temperatures of three distinct intervals within the northern Permian Basin, USA. X-ray diffraction of clay fractions (<2 µm) consists of illite, chlorite, and illite-smectite intermediates. Primary clay mineral diagenetic changes progressively increase in ordering from R0 to R1 I-S between 2359.5 and 2485.9 m and the appearance of chlorite at 2338.7 m. Rock-Eval pyrolysis data show 0 to 14 wt% TOC, HI values of 40 to 520 mgHC/g TOC, and S2 values of 0 to 62 mg HC/g, with primarily type II kerogen with calculated %Ro within the early to peak oil maturation window. Evaluation of the potential for oil generation is relatively good throughout the Tonya 401 and JP Chilton wells. Organic maturation indices (Tmax, %Ro) and peak burial temperatures correlate well with clay mineral diagenesis (R0–R1 I-S), indicating that maximum burial depths and temperatures were between 2.5 and 4 km and <100 °C and 140 °C, respectively. Additionally, the use of clay mineral-derived temperatures provides insight into discrepancies between several calculated %Ro equations and thus should be further investigated for use in the Permian Basin. Accordingly, these findings show that clay mineral diagenesis, combined with other paleothermal proxies, can considerably improve the understanding of the complex burial history of the Permian Basin in the context of the evolution of the southern margin of Laurentia.

Facile synthesis of up‐conversionCit‐NaYF4:Yb,Tm @phenol‐formaldehyde resin@Ag composites for the sensitive detection ofS2−

AbstractIn this work, we synthesized the core‐shell structure citric acid‐modified up‐conversion luminescent nanoparticles (Cit‐NaYF4:Yb,Tm) (denoted as UC)@ polymer of phenol‐formaldehyde resin (PFR) particles. Ag nanoparticles were successfully loaded onto the PFR's shell by direct reduction of AgNO3in situ with rich hydroxyl groups in PFR and a new application of the UC@PFR@Ag composites for detection of S2−was investigated. A good linear relationship between the fluorescence intensity of as‐synthesis of UC@PFR@Ag composites and the concentration of S2−could be found within the range of 2–100 nM (R2= 0.9929) with a limit of detection of 0.67 nM. The values of S2−content in actual water samples obtained with the proposed method are much closer to unity as compared to the corresponding values obtained with the UV method.

Application of PCA and HCA in geochemical parameters to distinguish depositional paleoenvironments from source rocks

Oil-producing rocks can be characterized by organic, inorganic and palynological geochemical parameters to assess the quantity and quality of organic matter. In the present study, samples of source rocks collected from different formations (Fm) from the sedimentary basins of the Parnaíba (Pimentairas Formation) and Paraná (Irati and Ponta Grossa Formations) were evaluated through the geochemical correlation between the types of organic matter and their different depositional paleoenvironments using chemometric tools. Among the inorganic geochemical parameters used in this evaluation are the concentrations and the diagnostic ratios between the transition elements (Co, Ni, V, and Mo) and internal transition (lanthanides and U). The analysis of the transition and internal transition elements were performed by ICP OES (Ni and V) and ICP MS (Co, Mo, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb, Lu, and U). The organic geochemical parameters selected for the characterization of the quantity and quality of the organic matter present in the samples of source rocks involved the determination of their total carbon content (%TOC) and sulfur (%TS), of the potential generator (S2) the amount of hydrocarbons produced by Rock-Eval pyrolysis and the calculation of the hydrogen (HI) and oxygen (OI) indexes. To compose the matrix of the multivariate analysis (PCA), were used ratios Ni/Co, V/Ni, U/Mo, V/V + Ni, TOC/TS the values of S2, HI, OI and the sum of rare earth elements (REE). The kerogen type, obtained through the HI and OI data, were also included in the matrix, information on the origin of the organic matter, and on the type of depositional paleoenvironment of each sample, obtained from previous works. It was observed the formation of three groups of data characterizing the formations Irati, Ponta Grossa and Pimenteiras according to the type of kerogen and organic matter, and also of its depositional paleoenvironment, showing that the exploratory data analysis allows the obtaining of rapid and efficient information on the chemical similarity between the complex samples from each formation.

The effect of volcanism to the source rock maturity in Gunung Endut area: Insight for subvolcanic hydrocarbon exploration

Banten region is known to have subvolcanic hydrocarbon system but no proven play despite oil seeps and the potential source rock have been identified in this area. A Geochemical analysis of source rock have been done on Gunung Endut, Banten Province. There are four coaly shale sample from Genteng Formation and Bojongmanik Formation collected and analysed in this study. The purpose of this study is to understand the influence of volcanic environment towards the quality, quantity and maturity of source rock based on TOC, pyrolysis, and vitrinite reflectance analyses. The result obtained showed TOC value between 8–18 wt% which indicated excellent petroleum potential from the source rock. In addition, Pyrolysis data showed S1 value between 0.05–0.19, S2 value between 1.52–11.53, S3 value between 4.10–7.57 and Tmax 414.8–523.2 °C. From both analyses, TOC and Pyrolysis, the source rock is categorized as Type 3 Kerogen producing gas and Type 4. Based on its maturity, three sample are categorized as immature while one specimen is categorized as postmature. Furthermore, Vitrinite Reflectance analysis result shows Ro value between 0.27–0.63 that support the result of pyrolysis analysis. Maturity anomaly found in the sample is presumed to be caused by intrusion that have been identified by the geological mapping in the same region. The condition on the surface may also reflect the source rock in the subsurface. A number of source rock in Banten region may be matured due to intrusion that related to volcanic activities. Subsurface zone with abundance igneous bodies will have different maturity compare to other area. Hence, it is important for petroleum exploration activities in Banten region or other volcanic area to properly identify the distribution of subsurface igneous body due to its effect to the source rock maturity.

A new strategy to the NaY(MoO4)2:Eu3+ phosphors modified by tetraethyl orthosilicate for LEDs: Photoludminescence properties and morphology

NaY(MoO4)2:Eu3+ microcrystals with different morphologies have been successfully synthesized via a hydrothermal method by varying the molar ratios of tetraethyl orthosilicate (TEOS). The structure and photoluminescence properties of phosphors are investigated by the X-ray powder diffraction (XRD), transmission electron microscope (TEM), the ultraviolet-visible diffuse reflectance spectra (UV–vis DRS), photoluminescence excitation (PLE) and emission (PL) spectra as well as the decay curves. There are two intense PLE peaks at 395 and 465 nm in the PLE spectra, which well matched with the near ultraviolet (NUV) and blue GaN-based light-emitting diodes (LEDs). In the PL spectra, the strongest PL peak is caused by 5D0 → 7F2 electric dipole transition. In addition, the amount of TEOS has an important impact on the morphologies and PL intensity of samples. With the increase of the amount of TEOS, the morphologies of the samples vary from double shuttle-like architectures, truncated rhombic polyhedrons, to quasi-cubes. It is found that the International Commission on Illumination (CIE) chromaticity coordinates of phosphors are located in red region, and the color purity is 99.70 % for S2 sample. Besides, the correlated color temperature (CCT) values of S1−3 samples are in the range of “warm appearance”. Therefore, the above obtained results suggest that the samples possess potential application value in the field of optical display systems, photoelectric devices and LEDs.

13C NMR Relaxation Analysis of Protein GB3 for the Assessment of Side Chain Dynamics Predictions by Current AMBER and CHARMM Force Fields.

Molecular simulations with seven current AMBER- and CHARMM-based force fields yield markedly differing internal bond vector autocorrelation function predictions for many of the 223 methine and methylene H-C bonds of the 56-residue protein GB3. To enable quantification of accuracy, 13C R1, R2, and heteronuclear NOE relaxation rates have been determined for the methine and stereochemically assigned methylene Cα and Cβ positions. With only three experimental relaxation values for each bond vector, central to this analysis is the accuracy with which MD-derived autocorrelation curves can be represented by a 3-parameter equation which, in turn, maps onto the NMR relaxation values. In contrast to the more widely used extended Lipari-Szabo order parameter representation, 95% of these MD-derived internal autocorrelation curves for GB3 can be fitted to within 1.0% rmsd over the time frame from 30 ps to 4 ns by a biexponential Larmor frequency-selective representation (LF-S2). Applying the LF-S2 representation to the experimental relaxation rates and uncertainties serves to determine the boundary range for the autocorrelation function of each bond vector consistent with the experimental data. Not surprisingly, all seven force fields predict the autocorrelation functions for the more motionally restricted 1Hα-13Cα and 1Hβ-13Cβ bond vectors with reasonable accuracy. However, for the 1Hβ-13Cβ bond vectors exhibiting aggregate order parameter S2 values less than 0.85, only 1% of the MD-derived predictions lie with 1 σ of the experimentally determined autocorrelation functions and only 7% within 2 σ. On the other hand, substantial residue type-specific improvements in predictive performance were observed among the recent AMBER force fields. This analysis indicates considerable potential for the use of 13C relaxation measurements in guiding the optimization of the side chain dynamics characteristics of protein molecular simulations.

Silurian qusaiba shale: Petrophysical, mineralogical and geochemical analysis

The organic rich Lower Silurian Qusaiba Shale is the main effective source rock for most of the Paleozoic hydrocarbon in Eastern and central Arabia. Outcrop samples were obtained from Tayma quadrangle, northwest Saudi Arabia and extensive analyses were performed including petrophysical, geochemical, mineralogical, elemental, paleontological and lithofacies identification. Visual observation of samples tested shows highly cemented, thinly laminated and silty micaceous shale, light to dark grey in color with wide range of grain size. Paleontological analysis indicates no trace of micro or macrofossils presence in the studied samples. Elemental XRF analysis indicates major oxides of silica, calcium and alumina, reflecting the composition of the shale samples detected by XRD analysis. Silica sulfur, potassium, calcium, magnesium, titanium and high iron content reflect the presence of the quartz, pyrite, biotite, anhydride, clay minerals and iron oxides. The chemical index of alteration (CIA) and the chemical index of weathering (CIW) indicate relatively deep marine paleoclimate environment with intermediate to strong weathering conditions. High iron contents and presence of traces of titanium oxides confirm the mafic source of these shales. The lithofacies variation and mineralogy were tested using SEM/EDS and different pore systems namely organic, non-organic, and micro-fractures were recognized. Image processing indicate the presence of large macro size organic pores and Mercury Intrusion Porosmetry supports that indicating one meso and three macro pore size ranges with average porosity and permeability of 7.8% and 1.56 nD respectively. Geochemical analysis shows TOC slightly over 2 mg/g indicating good hydrocarbon generation potential with low S2 and HI values, indicating mature kerogen with gas prone type III. The results obtained confirm the potential of the Qusaiba shale and provide more insight on the characteristics of this formation.

Evaluation of Ranikot Sandstone Formation, Punjab Platform Basin Pakistan

Abstract The Ranikot sandstone Formation was investigated using TOC and Rock-Eval pyrolysis measurements. Ranikot Formation encountered in Bijnot well, Fort Abbas has been evaluated, which lies in Bahawalpur, middle Indus basin, particularly in Punjab platform. Analysis has been performed on sandstones, twenty well cutting samples of Ranikot Formation has been evaluated. Formation is predominantly sandstone with interbeds of shale. The analysed samples contains TOC ranging from 0.76-3.1 wt.%, The S2 values of Rock-Eval shows poor potential with values ranging from 0.46-1.05 mg HC/g rock. The samples have low hydrogen index values ranging from 21-113 mg HC/g TOC. Kerogen is predominantly Type III land derived organic matter. The analysed samples have Tmax ranging from 413-509 °C. The upper part of formation from 490-560m depth generally exhibits good to very good TOC content and is in the transition between immature and mature zone (Tmax 430-431 °C). The genetic potential in the entire rock unit is poor < 2.0 mg HC/g rock. On the basis of analysis performed the studied samples have shown that the formation has poor potential.

Environmental impacts and cost overrun derived from adjustments of a road construction project setting

Road infrastructure works are complex and important undertakings for the social and economic development of a country. They are based on studies that ensure the technical, environmental and economic feasibility of the work. These studies are the basis of the road executive project, which includes the projects that characterize the work to be performed. Road constructions can be considered as horizontally arranged, integrated and complementary activities, so that each of them establishes boundary conditions that affect all the others. Thus, modification of any part of the project changes the proposed scenario for the execution of the following work stages. Most executive road construction projects must be readjusted during the construction because of deficiencies and incomplete surveys and field studies. Those modifications extend the construction period of the road, alter the contractual value and the environmental impacts of the work. This paper investigates the environmental impacts, associated with the input and output flows, as well as the cost overruns of the construction of a road, considering the activities foreseen in the awarded project (scenario S1) and those executed by the construction company (scenario S2) using a Life Cycle Assessment (LCA). The adjustments done in scenario S2 accounted for an average increase of 16% of the environmental impacts in relation to S1 impacts. The critical stages of those activities were clay mining, embankment construction, base construction, and paving. Although the clay and soil volume moved in the construction process was five-fold higher than the volume of aggregate material, the impacts of the exploration and processing of the rock aggregates were 27% higher. Comparing the costs of both S1 and S2 scenarios, the final contractual values of scenario S2 were average 30% higher than the scenario S1 projected costs. Specifically, the S2 costs of earthwork and paving stages were 45% and 11% higher than S1 respectively. The ground of cost overruns and delays during construction are forecasting errors for soil movement and usage of rock aggregates. The results also shown that LCA application after to completing the executive design of a road can help road designer and contractor during the decision-making processes, to anticipate the potential environmental impacts that road construction can produce, as well as predict the environmental effects of changes on the executive project.

Organic facies and palynology from the middle to late Devonian of the Pimenteiras Formation, Parnaíba Basin, Brazil

A detailed study of organic facies and palynological assemblages was carried out on 11 samples of potential hydrocarbon source rocks of the Pimenteiras Formation, an outcropping at the western edge of the Parnaíba Basin, Brazil. The main objectives are to characterize the depositional paleoenvironment and hydrocarbon source potential. The selection of this outcrop occurred in the function of its preservation and accessibility, and the samples collection observed 1 m of vertical spacing. Generally, the organic matter and the palynomorphs showed a good state of preservation and fluorescence. The most notable spores and acritarchs and phycomates species were discussed in light of international biozones, and the chronostratigraphic range defined as Late Eifelian - Latest Frasnian in age. TOC results show ranges from 0.40 to 2.91%, with most samples showing greater than 1%, thereby holding a high potential generation. The S1 values were virtually null, and the S2 peak ranged from 0.9 to 5.33 mg/g. The kerogen 435 °C, and the ICE between 4.0 and 4.5 demonstrating the material immaturity. For the palynofacies associations definition, only 10 out of the 25 total quantified of subgroups of kerogen categories were considered in the counting of 300 particles. A dendrogram constructed based on these results through cluster analysis, revealed four palynofacies, as follows: I constituted mainly by palynomorphs (acritarchs, prasinophytes and sporomorphs); II – Dominance of Translucent organic matter (cuticles, epidermal tissue and translucent phytoclasts with and without structure); III - Dominance of Opaque/non-fluorescent (opaque phytoclasts and non-fluorescent AOM) and IV - Dominance of AOM fluorescent (amorphous organic matter with fluorescence). The palynomorphs are the most abundant constituents of all studied kerogen. Quantitative analysis based on the distribution of palynomorphs groups throughout the section indicates the dominance of sporomorphs in the palynological assemblages from the Middle Devonian aged samples. On the other hand, occurred the predominance of microplankton elements in the Late Devonian aged samples. Thus, the depositional paleoenvironment was established as a distal oxic mud-dominated shelf with the deltaic influence of the Late Eifelian to Late Givetian, and there is a tendency distal (dysoxic-anoxic ‘shelf’) from the Frasnian, which indicates the maximum flooding surface.

Delineation of factors that control hydrocarbon source rock maturity in Anambra and Abakaliki Basins South-Eastern Nigeria

Outcrop information from Abakaliki and Anambra were used in this study to characterize the source and reservoir rocks in the two basins in order to give indication(s) for hydrocarbon generation potential in the basins to minimize uncertainty and risk that are allied with exploration and field development of oil and gas. Outrop mapping method was used to carry out geological, stratigraphical, geochemical, structural, petrographical, and sedimentological studies of rock units from outcrop sections within the two basins. Thirty-eight samples of shale were collected fromthese Basins in stratified mode of random sampling, and geochemical analysis (rockeval) was performed on the samples to determine the total organic content (TOC) and to assess the oil generating window. The results were analyzed, to properly characterize the potential source rock(s) and reservoir rock(s) in the basins, and factor(s) that can favour hydrocarbon traps. The results of the geological, stratigraphical, sedimentological, geochemical, and structural mapping were used to develop a new model for hydrocarbon generation in the Basins. The result of the geochemical analysis of shale samples from the Anambra Basin shows that the TOC values are ≥𝟏𝒘𝒕%, Tmax ≥𝟒𝟑𝟏℃, Vitrinite reflectance values are ≥𝟎.𝟔%, and S1+S2 values are >𝟐.𝟓𝒎𝒈/𝒈 for Mamu Formation while shale samples from other formations within Anambra Basin fall out of these ranges. The shale unit in the Mamu Formation is the major source rock for oil generation in the Anambra Basin while others have potential for gas generation with very little oil generation. The shale samples from Abakaliki Basin show that S 1 +S 2 values range from <𝟏−𝟐𝟎𝒎𝒈/𝒈, TOC values range from 0.31-4.55wt%, vitrinite reflectance ranges from 0.41-1.24% and Tmax ranges from 𝟒𝟐𝟑℃−𝟒𝟔𝟔℃. This result also shows that there is no source rock for oil generation in Abakaliki Basin; it is either gas or graphite. Keywords: Source rock, kerogen type, Abakaliki Basin, Anambra Basin, Oil generating window

The Petroleum System of Zubair Formation in Zubair Subzone, Southern Iraq

The Lower Cretaceous Zubair Formation is the most important reservoir in the south of Iraq and adjacent countries, as well as the shale intervals, may be the possible source rock. The parameters of the possible source rock within Zubair Formation are accepted, regarding quantity, quality, and thermal maturity.&#x0D; From the total organic carbon values standpoint, shale intervals of Zubair Formation are generally good source rocks, except in the lower parts. While the kerogen types are generally type III gas-oil prone, mix type II/III, and type II oil-prone. The main type of organic matters was amorphous organic matters, which is principally related to oil-prone source rock.&#x0D; The Rock-Eval Pyrolysis shows that the organic geochemical properties presented an effective and/or potential source rock depending on the values of S1, S2, and S3 and their derivatives. The source rock has started the oil expulsion, where the S1/TOC values were mainly more than 0.2 mg HC / g TOC.&#x0D; The modelling explains that the Zubair Formation, wholly, has been entered the onset, partially, the peak, and rarely the end of oil generation in the studied Subzones. This conclusion depends on the calculated temperatures, geothermal gradients, and Vitrinite reflectance calibration.