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This paper is devoted to the study of aquathermolysis processes of heavy oil produced by CSS technology on Boca de Jaruco oil field. Various catalysts based on cobalt, nickel, iron and copper were used for intensification of in-situ upgrading processes of heavy oil. The first paper in series is presented results of transformation of crude oil and its saturate fraction after thermal treatment with and without catalysts by SARA analysis, MALDI mass-spectrometry, FTIR-spectroscopy and gas chromatography. It is revealed, that catalysts provide more deep conversion of asphaltenes and resins into lighter hydrocarbons. Particularly, for the given heavy oil, catalysts based on iron and nickel organic salts are more effective to reduce the content of high molecular weight components (asphaltenes). Saturates fraction after thermal treatment in presence of the catalysts is enriched with lighter alkanes in comparison to the crude oil treated without catalysts. Obtained results show that crude oil recovered by catalytic aquathermolysis processes will be better quality than the original oil in the place. [ABSTRACT FROM AUTHOR]

In this paper, the Hubbert fluid potential model is used to restore the fluid potential of the key reservoir forming period at the end of Paleogene in Shijiazhuang Sag. At the end of Paleogene, the high potential area of Shijiazhuang Sag is mainly located in the Western trough belt of the sag, which is the main flow supply area. The low potential area of the sag is mainly distributed in the Gao cheng tectonic belt in the middle, which is the main discharge area. The overall performance is the distribution law of the trough to the central buried hill belt, and the potential energy gradually decreases. The sag is further divided into three major oil and gas migration and accumulation units, namely, the southern oil and gas migration and accumulation unit (III), the central oil and gas migration and accumulation unit (I), and the northern oil and gas migration and accumulation unit (II). Among them, the central oil and gas migration and accumulation unit (I) is the best oil and gas migration and accumulation unit, which receives multi-source hydrocarbon supply and has favorable reservoir forming conditions. [ABSTRACT FROM AUTHOR]

In this paper, two types of machine learning, namely neuro-fuzzy inference system (ANFIS) and multilayer perceptron (MLP), have been studied to model light hydrocarbons' solubility solvent in bitumen. The 268 number of experimental data is used in this work from different articles. The input parameters are Temperature (T), pressure (P), and molecular weight (MW) of hydrocarbons. The result shows the high performance of the MLP model with a two layers to predict the experimental values. The estimated values were investigated by statistical parameters such as R2, MSE, and MARD%. According to, statistical parameters, the values of 0.99, 0.00081, and 0.68 for MLP, and 0.96, 0.0029, and 0.78 for ANFIS indicate the high performance of the MLP model. Comparison between established models and previous work indicates that the developed model can be a suitable technique for solubility modeling [ABSTRACT FROM AUTHOR]

In this paper, the gas composition and isotopic characteristics of the tight sandstone of the Upper Triassic Xujiahe Formation in the western Sichuan depression were analyzed, and the origin of hydrocarbon gas, rare gas and CO2 in natural gas were determined. The hydrocarbon gas content in the tight sandstone gas of the Xujiahe Formation is the highest, ranging from 96.43% to 99.44 vol.%, while the non-hydrocarbon gas content is only 0.34–2.73 vol.%. The hydrocarbon gas has the highest content of CH4, which is distributed from 88.52% to 97.86 vol.%, and the content of other hydrocarbon gases is relatively low. The studied natural gas is mainly dry gas, and a small part is wet gas. According to the hydrocarbon gas component and carbon isotope analysis results, it showed that the natural gas of the Xujiahe Formation was a thermogenic gas, and there was no mixing of biogenetic gas. The natural gas was derived from the thermal degradation of the humus kerogen. Moreover, the rare gas in the natural gas of the Xujiahe Formation is a crustal origin organic gas, and there is no mantle origin gas, which indicates the lack of inorganic components in the natural gas. We also found that the CO2 in the natural gas is mainly inorganic gas, which is derived from the dissolution of carbonate minerals; and only a small part is organic thermogenic gas, which is derived from the thermal maturation process of organic matter. [ABSTRACT FROM AUTHOR]

Various studies have shown that miscible displacement by alternating the injection of hydrocarbon solvent and water recovers more residual oil than either solvent injection or waterflooding alone. However, economic considerations have limited the amount of solvent that could be injected during the miscible displacement process and has constrained its application for maximum oil recovery. Statistical modeling techniques were used to analyze various field and laboratory studies in which miscible displacement by hydrocarbon solvent and injected water were implemented. This provided an avenue to describe the performance of solvent-aided-waterflooding displacement and effect of various parameters on this process. The amount of hydrocarbon solvent, ratio of injected water to solvent and formation thickness were incorporated in the model to establish their relationship with incremental oil recovery. Multiple regression analysis was used to develop the model and the result indicated that future performance of the solvent-aided-waterflooding displacement process could be predicted effectively. [ABSTRACT FROM AUTHOR]

Immobilization technology is a method for restoring the ecological environment of oil-polluted areas. In this paper, the performance and degradation characteristics of immobilized microorganisms on different carriers were systematically studied starting with the selection of immobilized carriers. The results showed that cinnamon shell was the best carrier for screened Pseudomonas YT-11 to prepare immobilized microorganisms (diesel degradation rate was 69.57% in 5 days). On the basis of the determination of diesel degradability and SEM structure, the degradation mechanism of immobilized microspheres was concluded: diesel was adsorbed on the surface of microspheres and then entered the interior to be degraded by microorganisms. [ABSTRACT FROM AUTHOR]

The RePu area is located in the Tarim Basin, China. Based on the exploration and development, this paper analyzed the characteristics of the Ordovician crude oil and the source rocks by gas chromatography-mass spectrometry. The Ordovician carbonatite reservoir oil in this area exhibited light component, rich chain hydrocarbon and poor aromatic hydrocarbon. The composition of C7 compound showed the advantage of n-heptane, which belonged to type I generative kerogen, and it was deep buried highly mature crude oil. The crude oil biomarker compounds all exhibited high content of long-chain tricyclic terpanes and high Ts/Tm values. The large presence of alkane aromatization compounds indicated strong reducing environmental conditions during crude oil formation. By comprehensive judgment that the main oil source of the Ordovician reservoirs in the RePu area was the Cambrian source rock. [ABSTRACT FROM AUTHOR]

55 source rock samples in the Carboniferous-Permian strata, southern Northern China basin were analyzed in this paper to obtain the sedimentary characteristics, organic matter abundance, kerogen type and thermal maturity and the unconventional oil and gas prospects. The results demonstrated that the source rocks were all dominated by the evolution of the sedimentary environment. High thermal evolution resulted in low S1, whereas poor preservation caused by strong tectonic activities resulted in low S2. The units of the southern North China Basin with weak tectonic activity and good preservation conditions may be the main areas for future unconventional gas exploration. [ABSTRACT FROM AUTHOR]

Asphaltenes have adsorption and occlusion properties, and the study of the compounds adsorbed and occluded in them can characterize the evolutionary processes occurring in the oil reservoir. In this paper, the adsorption properties of asphaltenes isolated from bitumoid of Domanic formation of the Republic of Tatarstan (Russia) were studied. It was found that asphaltenes adsorbed to a greater extent the polar resins and to a lesser extent - the nonpolar resins and the saturated hydrocarbons. It was shown that adsorbed resins were enriched in aromatic structures with poor alkyl substitution, and adsorbed saturated hydrocarbons were enriched in high molecular weight n-alkanes in comparison with compounds present in maltenes of bitumoid. Asphaltenes, after adsorbed compounds were extracted from them, became more carbonized. The assumption was made that vanadyl porphyrin complexes were occluded in asphaltenes rather than adsorbed on them. [ABSTRACT FROM AUTHOR]

Current paper represents the results of the study on extraction of hydrocarbons from oil emulsions using liquid and supercritical extraction processes. High-viscosity oil from Ashalchinskoye accumulation has been taken as a base for the emulsions with subsequent addition of water (0.5-30% wt.). A mixture of propane and butane has been applied as an extractant. The investigations have been carried out at temperatures 85-140 °C and pressures 10-15 MPa. The achieved output of light hydrocarbons is 93% of the total mass of hydrocarbons in emulsion. In parallel with the extraction, deasphaltizing has also been carried out. [ABSTRACT FROM AUTHOR]

The exploration and development of shale gas reservoirs has been of growing interest in the industry in recent years. It has been widely acknowledged that, during different thermal evolution stages, some characteristics including: the hydrocarbon-generation mechanism, development of organic matter pores, and methane storage/transport mechanism in organic matter/pores will affect shale gas desorption and production fundamentally. However, current research has failed to reveal them completely, which introduces large discrepancies between actual and predicted production in some shale gas reservoirs. In this paper, for the four thermal evolution stages of shale organic matter, i.e., the biochemical, thermo-catalytic, thermo-cracking and deep high temperature phases, respectively, characteristics of products generated from shale kerogen, including the form and quality of the solid frame, gas-oil ratios, and pore characteristics in organic matter (e.g., types of pores, pore wall materials) were first investigated. A new classification method for organic-matter pores was proposed. Additionally, methane absorption characteristics in shale organic matter and pores were demonstrated, the fact that water is involved during each thermal evolution phase was addressed, and current theories of solid-gas interface adsorption/desorption in the organic matter in shale were questioned. This work concluded that the system of solid-gas interface differs from actual shale reservoirs, so predicting production based on this understanding leads to significant inaccuracies. This work explained the possibility of solid-liquid interface effects in the organic matter of shale through analyzing product-generation and pore-formation mechanisms during the evolution of shale, which will directly affect potential reserves of shale. Therefore, this work should provide a basis for improving the accuracy of production predictions in actual reservoirs and should assist analysts in determining reasonable shale gas targets. [ABSTRACT FROM AUTHOR]

Hydrocarbon potential evaluation of shaly sand layers requires the adoption of certain shaly water model and also the selection of suitable conventional logging suite. The main target is how to get the accurate porosity and how to convert the apparent water saturation to true water saturation for given shaly sand layer. In this paper neural network approach is presented to replace the conventional interpretation of well logging data to better determine formation porosity and water saturation and to well identify hydrocarbon potential of clean and shaly sand layers. Two neural networks were constructed, one for prediction of porosity using six well logging data inputs: GR, LLD, RHOB, NPHI, PEF, and Δt); and water saturation using five well logging data inputs: GR, LLD, RHOB, NPHI and PEF. Shale volume was defined from GR data. Each neural network is trained using available logging data and validated using the core data before applying it to the entire well log. Neural network predicted formation porosity and water saturation for tested sections of one well. Also using the cut off values of porosity, water saturation and shale volume, the neural network defined the possible pay zones in the well. Network outputs have shown good matching with core data and the reference calculated petrophysical parameters. The developed network approach has successfully deduced porosity, water saturation and defined pay zones in a new well that projects its application for new wells. [ABSTRACT FROM AUTHOR]

In this paper, the history of Karatau strike-slip fault and its control on inversion structures and hydrocarbon migration of the Aryskum depression were discussed. Karatau fault was characterized by sinistral strike-slip in the early stage and dextral strike-slip in the late stage. Lots of positive inversion structures in the Aryskum depression formed by the dextral strike-slip movement during Eocene-Oligocene, which synchronized with the main generation and expulsion stages of major source rocks, becoming favorable traps for hydrocarbon accumulation. Karatau fault also dominated the direction of hydrocarbon expulsion and migration in the J1and J2source rocks by altering their layer shapes, resulting in higher hydrocarbon enrichment in the depression center than that in the flanks. Meanwhile, as the thickness of regional cap rock in the middle and northern parts of the Aryskum depression is obviously higher than that in the relevant vertical fault throws which has caused little hydrocarbon dissipation from the fault, the hydrocarbon enrichment in the middle and northern parts of the depression is higher than that in the southern part. [ABSTRACT FROM AUTHOR]

Wettability alteration mechanism is still believed to be the main contributor to low salinity water injection (LSWI) effect on oil recovery from carbonate rocks. The authors investigated the main mechanism and contributor to the LSWI effect on oil recovery from carbonate rocks through history matching recently published corefloods using the UTCHEM simulator. The history match results suggest that wettability alteration has negligible effect on water relative permeability, which could be related to the double electric layer expansion mechanism. This paper provides a basis to develop a LSWI model to predict oil recovery from carbonate rocks. [ABSTRACT FROM PUBLISHER]

Understanding hydrocarbon microseepage mechanism is important for interpreting hydrocarbon anomalies in the surface geochemical exploration. An experiment was developed to simulate the vertical microseepage of hydrocarbons with multiple lithological layers. The results revealed that the microseepage below the water table was dominated by buoyancy of microbubbles with diffusion as a secondary mechanism, however, it was dominated by diffusion with little effect by gas convection above the water table. The micro-fractures were the dominant channels for microseepage. A phenomenological model was developed to quantify the vertical microseepage in different media and provided a better tool in a field environment. [ABSTRACT FROM AUTHOR]

Rock-eval pyrolysis is used to rapidly evaluate the petroleum generation potential and maturity of rocks. In the current paper, the geochemical characteristics of a probable source rock, Gadvan Formation, in south of Iran, Persian Gulf, was studied. To get the goal 56 ditch-cutting samples of 17 wells, drilled in Persian Gulf, were collected and analyzed using Rock-Eval pyrolysis. Pre-analyses of Rock-Eval outputs shows that only 33 samples are suitable for further investigations, as other ones has been contaminated by migrated hydrocarbons. Kerogen type III is dominating type in the samples, while few of them are type II. It seems that Gadvan is a gas prone formation, which can generate hydrocarbon due to its fair maturity in some intervals. The possible organic facies of Gadvan Formation are mainly reducing and deep marine environments with moderate rate of sedimentation, which confirm its potential to perform as a source rock in the area; however, few of samples were deposited in oxidizing condition based on the results of Jones diagram. Finally, the diagram of S2versus total organic carbon proved negligible mineral matrix effect and inert carbon in the understudied samples of Gadvan. [ABSTRACT FROM AUTHOR]

Soluble organic matter (SOM) content, group composition and gas chromatography of mud source rock of the Paleogene ranged 1000 m∼5000 m in Dongying Sag were analyzed. The results show that 3500 m is a conversion boundary for SOM. Under this conversion boundary, SOM has a significant role transformation as in depth less than 3500 m, SOM is the hydrocarbon product but in depth deeper than 3500 m, SOM mainly is the hydrocarbon precursor, and the resins play a major role in hydrocarbon generation. [ABSTRACT FROM AUTHOR]

Pressure–Volume–Temperature (PVT) empirical correlations result from analysis of experimental data collected from laboratory measurements of phase behavior properties of hydrocarbon systems. The correlations are only applicable for the tested hydrocarbons. They could nevertheless be used to predict PVT properties of similar hydrocarbons with pressures and temperatures falling within the measurements’ data range. The developed correlations are mostly, local, some are“region-bound” and a few are global. Regional and global correlations are used with caution. The reason being that hydrocarbon systems from different regions have different composition and paraffinicity, regardless of comparable temperature and pressure ranges. As a result and due to a complex geology resullting from unique depositional environments of most Omani reservoirs, a local correlation to derive PVT properties for Omani crude oils is needed. The correlations could also be used to supplement PVT experiments often time consuming and extremely costly. In this paper, the developed correlations are derived for undersaturated Omani black-oil. [ABSTRACT FROM AUTHOR]

Catalytic pyrolysis, which combines catalytic cracking and steam pyrolysis, is a technique to process petroleum hydrocarbons. Catalytic pyrolysis has the advantages of both catalytic cracking and steam pyrolysis. It can raise the yields of light olefins, expand the flexibility of products distribution, and simultaneously lower reaction temperature and decrease energy consumption for the whole system, so it has broad application prospect. Recent development on catalytic pyrolysis catalysts and technologies are reviewed in this paper, the similarities and differences of various kinds of catalysts are compared, notable processes in home and abroad are introduced, and three kinds of reaction mechanisms about catalytic pyrolysis are summarized for different types of catalysts and technologies. Owing to the shortage in supply and the inferior quality of China's crude oil, the study and development of catalytic pyrolysis techniques are crucial to China. Deep Catalytic Cracking, Catalytic Pyrolysis Process and Heavy-Oil Contact Cracking are introduced with emphasis. [ABSTRACT FROM AUTHOR]

The terminology “cloud point” has been traditionaly adopted by the American Society for Testing and Materials (ASTM) D2500 to refer to the temperature at which “cloudiness” of a relatively transparent petroleum fluid is observed upon cooling. The cloudiness forms as a “finite and detectable” amount of wax and/or paraffins precipitates from the test fluid contained in a 1½-in (~30 mm) diameter glass tube. Nowadays, more sophisticated techniques of differing measurement principles and varying degrees of sensitivity have been developed to measure cloud points of petroleum fluids including opaque hydrocarbon systems (dark oils). Alternative terminologies like wax appearance temperature (WAT) and wax precipitation temperature (WPT), amongst a few others, have also emerged and are used interchangeably. Meanwhile, numerous characterization and modeling efforts have been made to simulate “measured” cloud points of petroleum fluids. The goals of this paper are to provide an objective review of the concept of “cloud point” and to illucidate the adequacy and limitations of the measurement techniques and modeling approaches. [ABSTRACT FROM AUTHOR]

The problem of the instability of Fluidized Catalytic Cracked (FCC) Diesel is becoming an increasing concern in the refinery industry. The objective of this paper is to study the changes of non-hydrocarbons in FCC diesel during the deterioration of the stability by IR, GC and UV. It is demonstrated that during the storage or under stressing conditions, the diesel becomes deteriorated, and some unstable phenols, thiols and some nitrogen compounds involve in the color change and deposit formation. The content of thiols and phenols reduces during the accelerated aging of diesel. The contents of heteroatoms (S, N, O) in the deposit are a few times higher than that in the diesel. When phenols or thiols in diesel are removed, the stability of diesel is improved to some degree. [ABSTRACT FROM AUTHOR]

The accurate estimation of the water content of natural gas is the basis for proper equipment design in natural gas processing and transmission facilities. Methods for estimating the water content of natural gas have been reported based on pressure and temperature data, and the concentration of acid gases. This work aims to develop a predictive model based on artificial neural networks (ANN) to estimate the water content of natural gas, considering the contribution of heavier hydrocarbons than methane, commonly present in the rich gases, gas condensates, or liquefied petroleum gases. The novelty of the proposed model is the incorporation of natural gas richness (GPM) as an input parameter for calculating the water content of natural gas, in addition to temperature, pressure, and acid gas equivalent content. Experimental data from the literature is used in the ANN training and validation, with the help of the BigML machine learning platform to perform a multi-layer-feedforward neural network. The ANN performance showed the ability to accurately predict the water content for different gas mixtures (rich, lean, sweet, and sour gases). Comparisons with available models in the literature are performed, showing that the ANN model provides accurate estimations (AAD: < 10%). [ABSTRACT FROM AUTHOR]

The Lower Cretaceous Bayingebi Formation at the Hari sag, Northern China is a significant bearing oil-gas tight reservoir in the Yin'E Basin. In order to understand petrophysical properties of the reservoirs, the diagenesis and hydrocarbon accumulation phases were investigated using casting thin sections, scanning electron microscopy (SEM), X-ray diffraction and fluid inclusion analysis. Additionally, the histories of burial evolution, organic matter thermal evolution and hydrocarbon charge are investigated. The results showed that the pore types include primary pore, intergranular pore and dissolution intragranular pore. The diagenesis of sandstone reservoirs in the process of burial and diagenesis mainly includes compaction, fracture, cementation, metasomatism and dissolution. The comprehensive analysis of various diagenetic stage indexes shows that Bayingebi Formation is in the middle diagenetic stage A-B. The homogenization temperature and salinity of fluid inclusions are low temperature and low salinity (120 °C ∼ 130 °C, 0% ∼ 9%), medium temperature and high salinity (140 °C ∼ 150 °C, 10% ∼ 17%) and high temperature and medium salinity (160 °C ∼ 170 °C, 9% ∼ 11%) respectively. According to the homogenization temperature of the inclusions and the history of burial evolution, the Bayingebi Formation has mainly three phases of hydrocarbon accumulation (100 ∼ 97Ma, 93 ∼ 87Ma, 84 ∼ 81Ma). [ABSTRACT FROM AUTHOR]

The oil-gas display of early drilling suggests a considerable exploration prospect in the Nangong Sag. Previous researchers have not analyzed the characteristics of hydrocarbon migration and accumulation from the perspective of fluid potential. We use the Hubbert flow potential model to restore the flow potential of the Nangong Sag in the Pliocene, which was a key period of hydrocarbon generation. The results show that the high value area of fluid potential is large and mainly located in the southeastern part of the study area. The southeast subsag provided fluid, and the northwest slope accumulated fluid. The fluid potential gradual decrease from the southeast subsag to the northwest slope. According to the division trough theory, the Nangong Sag is divided into 8 hydrocarbon migration and accumulation units. We suggest that migration and accumulation units III, IV and V are favorable areas for hydrocarbon exploration. The study area has favorable source-reservoir-cap, pool-forming conditions and good time allocation relationship of hydrocarbon. Based on the characteristics of fluid potential, the hydrocarbon generation and accumulation modes of migration and accumulation unit III and IV in Nangong Sag are preliminarily put forward. The research results have guiding significance for future hydrocarbon exploration in the study area. [ABSTRACT FROM AUTHOR]

The zipper-frac technique is implemented in two adjacent horizontal wells to maximize the exposure of shale rocks. The hydraulic fractures are propagated in a manner in which they are connected with natural fracture network to improve the fracture complexity. In this study, the authors exploit the advantage of stimulated fracture complexity to access more of the hydrocarbons trapped in very low permeability of shale matrix. The recovery process efficiencies by cyclic CO2injection and CO2flooding in zipper-fractured horizontal wells are compared. The role of diffusion recovery mechanism in recovering oil from fractured shales will be discussed. [ABSTRACT FROM PUBLISHER]

An enormous number of pressure–volume–temperature (PVT) correlations have been developed over the years for different types of hydrocarbon systems. However, the accuracy of these correlations is often limited due to crude oil compositional difference, impurities, etc., from different geographical locations. The literature has revealed that the predictive capabilities of the previously developed PVT correlations for Nigerian crude oil system are still associated with large errors and as the accurate determination of the PVT properties is uncompromising, it is of great importance to develop new models for the Niger Delta region. In this study, we present new empirical PVT correlations for calculating bubble point pressure (Pb) and bubble point oil formation volume factor (Bob) using Niger Delta crude oil data based on multiple regression methods. Performance prediction based on statistical and graphical methods was carried out. The performance prediction results of the developedPbandBobcorrelations, when used to predict PVT data of crude oil system from different geographical locations, showed very high relative errors. This implies that in order to predict PVT data for a crude oil systems with high accuracy, local PVT correlations need to be developed. [ABSTRACT FROM AUTHOR]

Small and complex petroliferous sags have gradually become one of the key areas of succession in the mature exploration areas. Taking Weibei Sag of Bohai Bay Basin as a case, the geological and geochemical characteristics of the source rocks of Kong-2 Member was analyzed, the basin simulation method was used to determine the main hydrocarbon generation area, and investigate its control on the distribution and enrichment of hydrocarbon. The results show that the abundance, type, and maturity of organic matter have a large spatial variation range, and the upper and middle sub-members of Kong-2 Member in the study area are the most important source rocks. The periods of the late deposition of the Sha-4 Member and the structural uplift are the main hydrocarbon generation periods. The Migration of hydrocarbon-generating center from subsidence center to southeast direction, resulting a large amount of hydrocarbon-generating in the slope zone, leading to the main migration and accumulation direction of hydrocarbon in the Zaohu Faulted Nose Belt. Therefore, the hydrocarbon were enriched in the southeast and poor in the central and western regions, so the next favorable exploration areas include Zaohu Faulted Nose Belt, Eastern Wacheng Step Belt, and Southern Northern Sag Belt. [ABSTRACT FROM AUTHOR]

High-molecular-weight hydrocarbons and asphaltenes are important constituents of petroleum and can cause problems related to crystallization and deposition of asphaltene. This article introduces an extension of the cubic equation of state (Peng-Robinson EOS) to describe asphaltene–toluene mixture vapor–liquid equilibria (VLE) and characterize pure asphaltene, and the critical properties of asphaltene were adjusted. Experimental data were used to examine the proposed procedure in an Iranian crude oil reservoir. We determined the critical properties of asphaltene for this EOS using a two-phase vapor–liquid equilibrium calculation. The test results showed that the proposed procedure is adequate for predicting asphaltene precipitation data. [ABSTRACT FROM AUTHOR]

Hydrates are known to occur in a variety of natural-gas handling facilities and processing equipment in oil fields, refineries, and chemical plants when natural gas and water coexist at elevated pressure and reduced temperature. Prevention of hydrate formation costs large amounts of capital and results in large operating expenses. In order to avoid costly losses due to the formation of these hydrates, several methods, which include thermodynamic modeling and empirical correlations, can be employed to predict the conditions for hydrate formation. The authors employed SAS (SAS Institute, Cary, North Carolina) to develop a new correlation for predicting the hydrate-formation temperatures for both pure and mixture of hydrocarbon systems using the gravity method. The method correlates the hydrate-formation pressure against specific gravity, pressure, and water-vapor pressure. [ABSTRACT FROM PUBLISHER]

Aqueous-phase trapping (APT) in many petroleum reservoirs is a significant mechanism of formation damage during drilling and production operations. Evaluating a reservoir's potential for APT is of great importance where the reservoir is susceptible to APT, because well productivity can be improved through proper evaluation and consequent attempts to reduce associated formation damage. During the last 15 years, a number of formulas have been proposed to evaluate APT. In this article, the first effective parameters on APT are presented. Then formulas for evaluating APT are reviewed. To demonstrate practical application of formulas, check the validity of each formula, and compare predictions made by different formulas, some reservoirs are considered. [ABSTRACT FROM AUTHOR]

In this study, to have an accurate approximation of dynamic viscosity, radial basis function artificial neural network (RBF-ANN) is employed and developed for normal alkanes. This is done by considering the distinct number of carbons in n-alkanes, certain temperatures, and different pressures. Moreover, in order to train and test the predicting model, a databank of 228 experimental data is gathered from reliable sources in the literature. As a result, training and testing coefficient values are measured 0.99739 and 0.99051; consequently, the robustness and accuracy of RBF-ANN in providing an estimation of n-alkane viscosity is confirmed by graphical analysis and determined indexes. [ABSTRACT FROM AUTHOR]

There are many hydrocarbon generation sags around Dishuiquan Oilfield, such as Dishuiquan Sag, Dongdaohaizi Sag, Wucaiwan Sag, etc. But there is no result which hydrocarbon generation sag the Jurassic oil of Dishuiquan Oilfield is sourced from. Through comparisons on carbon isotopes, sterane distributions and maturities of source rocks and crude oil, the result shows that the geochemical characteristics of Jurassic crude oil in Dishuiquan Oilfield are highly consistent with those of Permian source rocks in Dongdaohaizi Sag and have obvious differences with other sags, which indicates the crude oil comes from the Permian source rocks in Dongdaohaizi Sag. [ABSTRACT FROM AUTHOR]

Based on the seismic data analysis, source rock geochemistry and reservoir physical properties, the source reservoir allocation and reservoir forming conditions in the Linhe-Jilantai area in Hetao Basin were studied. The results show that the source rocks of the Lower Cretaceous and the Oligocene in the study area reach the standard of fair-good source rocks, and the lithology of reservoirs is mainly feldspar sandstone and lithic feldspathic sandstone with good physical properties. Combined with vertical and lateral migration pathways, three hydrocarbon accumulation models of near source, far source and inside source are proposed. The research results can provide reference and guidance for the further hydrocarbon exploration in Hetao Basin. [ABSTRACT FROM AUTHOR]

The purpose of the present research was to estimate the heat of vaporization for petroleum fractions and pure hydrocarbons by the least-square support vector machine (LSSVM) as a function of the specific gravity, molecular weight, and boiling point temperature. Moreover, a particle swarm optimization technique was applied to determine optimal dependent parameters of LSSVM. In addition, results obtained from the proposed LSSVM model have been compared to some developed correlations by scholars. According to statistical observations, the LSSVM model has acceptable predictions by the value of mean relative deviation and R-squared (R2) equal to 0.51% and 0.9998, respectively. The present predictive manner can be used in petroleum engineering for an accurate approximation of heat of vaporization. [ABSTRACT FROM AUTHOR]

In this research, the response surface method designed by Box-Behnken was used to study the effect of temperature, pH value and TPH concentration on the biodegradation of Enterobacter sp. S-1contaminated soil. The value of determination coefficient (R2=0.9565) by analysis of variance (ANOVA) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that TPH degradation rate was more significantly affected (P < 0.0006) by temperature compared with other two parameters. In the temperature of 30 °C, pH value of 7.14 and TPH concentration was 4.83 g/L, the best degradation rate was 81.63%. [ABSTRACT FROM AUTHOR]

During CO2 flooding, extraction of lighter hydrocarbons from crude oil makes the remaining oil hard to be recovered. In this work, we design a new experimental method to characterize the effect of CO2 extraction on crude oil. The experimental results show that, the volume of extracted hydrocarbons increases as system pressure increases. The hydrocarbons with wider carbon number can be extracted from crude oil at high pressures. Moreover, the wax precipitation and viscosity of the remaining oil increase with increasing pressure. This study is expected to provide the basic understanding of the mechanisms of CO2 flooding for enhanced oil recovery. [ABSTRACT FROM AUTHOR]

The results of experiments on the transformation of heavy oil in a steam-laden environment, at temperatures and pressures ensuring the presence of water in a superheated steam state, as well as in the subcritical and supercritical states are presented. It is shown that supercritical water provides the largest formation of light fractions having a boiling point of 350 °C: their content has increased by 2.5 times. Subcritical water, in contrast to water in the supercritical state, ensures the formation of light fractions at 73% rel. and reduces the content of asphaltenes by 53% rel. compared with the initial oil. [ABSTRACT FROM AUTHOR]

The geochemical characteristics of the Yan 9 reservoir were analyzed by means of the group composition and the biomarkers in order to clarify the oil source of the Yan 9 reservoir in Jingbian Oil Field. The results showed that the n-alkanes are distributed with a single mode with C21 as the main carbon peak, C30hopane as the dominant biomarker, followed by C29hopane. Regular steroids are mainly C29, while C27 and C28 are similar, showing an asymmetric "V" distribution. The Yan 9 crude oil has similar geochemical characteristics and unified material source and evolution degree. It is a mature crude oil derived from a source deposited in a weak oxidation-reduction environment under freshwater conditions. Oil-source correlation showed that the reservoir of Yan 9 mainly comes from the contribution of Chang 7 hydrocarbon source rock in Jingbian Oil Field. [ABSTRACT FROM AUTHOR]

Reservoir properties of the fourth member of the Xujiahe Formation in the Western Sichuan Depression are quite poor (average porosity =5.9%, average permeability =1.41 mD). These properties were influenced by several diagenetic processes, especially compaction and carbonate cementation. Due to a combination of compaction of ductile fragments and carbonate cementation, sand/mud interfaces of the thick sandstone layer were tightly cemented, pore space also reduced sharply in positions where rich in ductile grains. Thus, space leaving for hydrocarbon is limited, except where both the detrital ductile grain content and carbonate cement content are low. [ABSTRACT FROM AUTHOR]

Study was conducted of rocks composition and its extracted moving hydrocarbons from Domanic deposits of Tatarstan, differing in location and occurrence depth from 1379 to 1891 m. The rocks are represented from carbonate-siliceous to pure carbonates with calcite content from 24 to 99%. With increase in calcite content in rocks, the yield of extracts from them decreases. Within Romashkinskoye field, an increase in yield of bitumoids with increase the occurrence depth of the host rocks - from 0.63 to 2.40% was established. Saturated hydrocarbons content of changes from 18 to 39%, of asphaltenes - from 9 to 26%. [ABSTRACT FROM AUTHOR]

Catalytic cracking of stearic acid (FFA) was carried out at atmospheric pressure to obtain short chain hydrocarbons for petrochemical replacement using alumina, sodium carbonate and hydrated magnesium carbonate (HMC) as a catalyst. All the three catalysts not only reduced the temperature but also the time required for cracking from 500 to 340 °C and 5 to 1:45 hours respectively. Cracking adopted the similar mechanism carried out in previous studies proven by the presence of n-alkane, alkene and carboxylic acid series with small amounts of aldehydes and ketones identified through Gas chromatography-Mass spectroscopy analysis. HMC was found a better catalyst regarding hydrocarbon formation produced 60.607 mole percent hydrocarbons at 350 °C using 10:1 (w/w) acid to catalyst mass ratio. HMC formed all hydrocarbons from C12-C17 in lesser cracking time 1:45 hours. [ABSTRACT FROM AUTHOR]

In this work we attempt to identify the geomicrobial fingerprints alongside with trace metals anomalies, and to explore whether the geomicrobial signatures are correlated with trace metals in El Hajeb oilfield in Tunisia. 51 soil samples are collected in grid pattern of 1 × 1 km interval. After incubating soil samples with propane in mineral salt medium, we count the propane oxidizing bacteria abundance ranged from nil to 2.44 × 105 cfu/g of soil sample. It was found that the concentrations of trace elements are enormously increased when they are compared with the natural background concentrations of metals in soils. [ABSTRACT FROM AUTHOR]

In order to enhance oil recovery of a conventional oil reservoir by CO2 flooding, the changes in the properties of the crude oil before and after CO2 flooding are systematically investigated by on-site sampling and experimental testing. The results show that, after CO2 flooding, the light hydrocarbons of the produced crude oil is increased and the heavy hydrocarbons of the produced crude oil is decreased due to the deposition of resins and asphaltenes in the pores of the formation. In addition, the produced fluid (a mixture of oil and water) has a high water separation rate, the oil- water interface has a high tension value, and the crude oil has a high acid value and a low viscosity. The conclusions can provide a certain guidance for high-efficiency development of a conventional oil reservoir by CO2 flooding. [ABSTRACT FROM AUTHOR]

Due to deeper buried, multi-stage tectonic influences, rapid changing, and unclear originate of oil and gas in Jinlong 2 wellblock, we analyzed the volcanic reservoir characteristics and the genesis of hydrocarbon by cores, thin slices, loggings, physical properties, oil testing data, and carbon isotopes. Results demonstrated that the major lithology were pyroclastic rocks and lavas, the reservoir was generally poor and strongly homogeneous, the main reservoir space were primary pores, and the favorable reservoir mainly developed in the pyroclastic rocks of the third phase. Furthermore, the results of carbon isotopes indicated that the crude oil and dissolved gas originated from Fengcheng formation, while the condensate gas derived from Jiamuhe formation. [ABSTRACT FROM AUTHOR]

In this work, amount of asphaltene adsorption onto the carbonate and sandstone rock samples was investigated at various initial concentrations of asphaltene in oil. Asphaltene adsorption onto both types of the reservoir rocks was increased by increasing the initial concentration of asphaltene. The amount of asphaltene adsorption onto the rock samples was predicted using Langmuir and Freundlich isotherm models. The results showed that Langmuir model had a better accuracy for prediction of asphaltene adsorption onto the rock samples than Freundlich model. Furthermore, asphaltene adsorption onto the reservoir rocks was studied in the presence of a recently developed asphaltene inhibitor. The inhibitor significantly reduced asphaltene adsorption at any initial concatenation of asphaltene. Moreover, changes in the rock permeability due to asphaltene precipitation were determined in the presence and absence of the asphaltene inhibitor. [ABSTRACT FROM AUTHOR]

Industrial waste polypropylene (PP) homopolymer and residual fuel oil (RFO) were pyrolyzed together in presence of catalyst ZSM-5 under the atmospheric pressure with different mixing ratios of the feedstocks. The experiments were carried out in a batch reactor at two different temperatures of 500 °C and 600 °C with the blended mixture (PP/RFO) to catalyst (ZSM-5) ratio of 4:1. The effects of blending ratios between the two feedstocks and temperature with respect to the yield of the products oil, gas, and residual coke were determined. The optimum blending ratio of PP and RFO with respect the higher quantity yield of liquid product was found to be 1:1 at 500 °C. The percentages of liquid fuel, gas, and coke were observed to be 74.8%, 10.2%, and 15% at 500 °C. [ABSTRACT FROM AUTHOR]

Hydrothermal influences on heavy oil were simulated in laboratory conditions. The experimental model was composed of oil, calcite, dolomite, and manganese oxide. Oil to dominant mineral ratio was 1:1, where the content of manganese oxide was 5%. The hydrothermal reactions were carried out under the reservoir temperatures of 250-300°С and a pressure of 1-2 MPa. As a result of treatment, aromaticity of oil increased, while H:C ratio decreased from 1.92 to 1.61. The structures of newly formed light fractions were characterized by low molecular aromatic compounds, which were the destruction products of resins. The treatment provided removal of nitrogen and sulfur from crude oil, hence, decreasing the viscosity of products. The genotype of crude oil did not change. The quantitative changes in the ratio of isoprenoid alkanes to the linear ones were evaluated via geochemical coefficients of group composition. [ABSTRACT FROM AUTHOR]

Detection of volatile organic compounds (VOCs) was done by a large number of studies in different methods and techniques among them are passive samplers because of their unique specifications technically and economically. In this study, passive sampler technique was used for monitoring of VOCs from spill crude oils in deep soil. Mathematical equations were achieved for the determination of time spill crude oil which depends on soil moisture content, soil temperature, and wind speed. The mathematical equations were driven from monitoring VOCs during three months. The results illustrated that the concentrations of n-Pentane was inversely diffused when compared with n-Nonane. [ABSTRACT FROM AUTHOR]

Asphaltenes were precipitated from a Venezuelan Ayacucho crude oil and separated into two fractions (A1 and A2) by the p-nitrophenol method. The asphaltenes and the fractions A1 and A2, as well as mixtures of the two fractions were tested in a Langmuir-Bodgett trough. It was found that the asphaltenes and the fraction A2 had similar behavior and higher compressibility than the fraction A1. This is because the molecules of A2 are more flexible than the molecules of A1 as they have aliphatic chains that bond aromatic structures while the A1 has an aromatic nucleus. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]