Abstract The common scientific issue presented by lithology prediction of tight sandstone reservoirs is that most primary lithologies cannot be distinguished effectively within the classic crossplots since they universally have similar logging responses. Lithology prediction actually is an issue of pattern recognition, and has been proved its best solver currently is machine learning technique. XGBoost

Abstract The study of the relationship of in-situ stress and permeability is of great necessity to understand the formation mechanism of high-permeability coal reservoir. However, characteristics of in-situ stress and its relationship with permeability in low-rank CBM blocks of China is poorly understood. This study employs permeability and in-situ stress test experiment to analyze the vertical variation

Abstract Severe loss of drilling fluids that occurs in Xinjiang, China, increases the Non-Production Time (NPT) and the overall cost of drilling. Magnesium oxysulfate (MOS) cement as lost circulation material has the advantages of short curing time, acid-soluble property and low cost, showing great potentials to solve severe loss. In this paper, the loss treatment of adding MOS cement directly into

Abstract Drilling fluids show significant role in the success of drilling operations of oil and gas well. Lubricating and rheological properties are important for efficient drilling leading to improved oil/gas production. The current work deals with assessing the lubricating properties of 16 different water-based drilling fluids using five lubricants and scrutinizing their consequence on the rheology

Abstract This paper presents a gas-water two-phaseLaminar-Inertial-Turbulent (LIT) flow equation for watered-out gas wells, which can be solved through the incorporation of daily production, gas-water relative permeability and PVT data, and then QAOF and formation factor (Kh) are obtained. Field case study in Long Wang Miao (LWM) water-drive gas reservoir shows that for watered-out gas wells, the single-phase

ABSSTRACT This paper studies the performance of in-depth gel treatment in a heterogeneous oil reservoir. A two-dimensional numerical model considering the disproportionate permeability reduction mechanism is developed to study the effects of gel on water permeability reduction and water viscosity enhancement. To describe the in situ gel formation, kinetic equation is provided to address polymer-crosslinker

Abstract The presence of heavy n-alkanes , together with CO2 and water, affects the accuracy of existing correlations used in equations of state. Moreover, they impact the performance of simulation software, resulting in flawed calculations. In this work, the most used correlations for predicting the properties of heavy n-alkanes are analyzed. Calculations were made using commercial software packages

Abstract A technical and economic analysis is done from simulations of propped hydraulic fracturing in low permeability reservoirs, as tight oil, in which the production from the well varies due to different well completion, each one is evaluated to determine the greatest economic performance. Working with a defined semi-integral system from the reservoir to the wellhead and focusing on well productivity;

Abstract The effects of different oxygen-containing air on enhanced oil recovery were evaluated by artificial cores with low permeability in displacement experiments. The results show that with the increment of oxygen content, more crude oil could be driven at the higher temperature and pressure, but the effect of oxygen concentration on oil displacement efficiency will be opposite at lower reaction

Abstract Viscosity of mixed oil is an important parameter which is required in transportation and production processes of mixed crude oils. There is no universal and general model for prediction of viscosity of mixed oils at different conditions. Hence, developing simple, accurate and general models for prediction of mixed oil viscosity is of great importance. In this work three computer based models

Abstract In this work, the transient pressure characteristics of vertical well with multi-wing complex fractures are carried out. A semi-analytical model of a complex fracture network is developed using the discrete flexible method. The mathematical model is resolved using the Laplace domain and the Stehfest inversion algorithm is used to draw the plate curves of each stage of flow in the reservoir

Abstract Surfactant adsorption is one of the crucial issues in surfactant flooding to enhance the oil recovery factor. In this paper, we investigated the profound impact of two different surfactants on the carbonate rocks adsorption density in different temperatures. According to the results of this experiment, carbonate rocks adsorption density increased with the increase of surfactant concentrations

Abstract CO2 injection and water-alternating-gas injection are EOR methods for improving oil recovery. This paper shows Water alternating gas (WAG) and continuous gas injection experiments with CO2 in secondary recovery. Experiments were performed in sand-packed-model. The continuous gas injection experiments were conducted at 3800, 4200, 4600 and 5000 psi, then two WAG experiments was completed at

Abstract Three correlations were developed for estimation of bubble point pressure, formation volume factor at bubble point, and solution gas-oil ratio. The data gathered from laboratory PVT data of Iranian oilfields. The robustness of the developed correlations was investigated using various methods. In addition, outcomes of the correlations were compared with the reported models in the literature

Abstract 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

Abstract Hydrogen index, HI, and original hydrogen index, HIo, are important indicators for measuring the hydrocarbon generation potential of the source rock. Through addressing the shortcomings of existent HIo models, improved models are proposed to improve the coincidence between calculated and measured results. According to the statistics of rock pyrolysis and TOC data of 1,249 cores taken in seven

Abstract Use of pour point depressants/flow improvers is an effective strategy for alleviation of flow problems associated with wax formation in paraffinic crude oil. Biobased oilfield chemicals derived from renewables are appealing as low-cost, eco-friendly alternatives to conventional pour point depressants. Cashew nut shell liquid (CNSL) extracted from Anacardium occidentale shells was modified

Abstract Formation damage is caused by invasion of the external reactive solid or liquid fluid into the reservoir which reduces the productivity of pay zone. This study investigates the efficiency of a biodegradable product which is stem peels powder of Grewia optiva tree as noninvasive fluid additive (NIFA) in the water-based drilling fluids. All the equipment were periodically calibrated with API

Abstract The complexity of the crude oil makes its compositional characterization a very challenging task. As a conventional way to characterize crude oil, SARA fractionation is based on the differences between the solubility and polarity of the four fractions: Saturates, Aromatics, Resins, and Asphaltenes. In this study, we present an improved method for SARA analysis: clay/alumina chromatography

Abstract By considering the long history of water injection in oil fields, we used several sandstone cores with different permeability to conduct experimental tests. The damage effect of formation permeability caused by five types of injected water based on an oilfield water quality standard (SY/T 5329-2012) was investigated. A model for water quality sensitivity to permeability was proposed, and through

Abstract Considering the low percentage of oil recovery in carbonate reservoirs, EOR methods receive more attention in these reservoirs, and smart water flooding shows some promising experimental results in carbonate rocks. Moreover, low operating cost and capital investment of water flooding compared to other chemical flooding methods, make this emerging technology more attractive for oil companies

Abstract Formation of wax can cause increase of pressure drop, blockages in the pipelines and interference with valve and instrumentation operation that causes loss of billions of dollars. Pour point depressant (PPD) is one of the wax treatment technique used widely in oil industry to alter the crude oil properties such as viscosity, wax appearance temperature (WAT) and pour point. The performance

Abstract This research aims to explore the effects of saturates, aromatics, resins and asphaltenes (SARA) fractions on the heavy crude oil pyrolysis behavior. The results showed that resins and asphaltenes had more pyrolysis residues (22.04% and 45.66%) relative to other samples. However, no residue was found after pyrolysis reactions when the oil mixed with SARA fractions. In addition, high temperature

Abstract Nitrogen (N2) and carbon dioxide (CO2) gases injection yield substantially various recovery ways. Here, a one-dimensional mathematical model is applied comprising of mass balances for explaining gas sorption and flow, and a geomechanical relationship to describe the permeability changes during gas injection. That’s why numerical simulations for investigating the performance of injecting flue

Abstract We study particle transmission in a deviated wellbore using computational fluid dynamics simulation. The effects of some drilling parameters on particle transport are studied such as particle characteristics, wellbore inclinations, and eccentricities. The particulate flow is simulated by the algebraic slip mixture (ASM) model, and the Herschel–Bulkley model expresses the rheology of the drilling

Abstract Comprehensive the analysis of cores, thin section, physical properties, mercury injection, and X-CT, genesis of heterogeneity of conglomerate reservoirs in Baikouquan formation of Mahu sag is studied. The Baikouquan formation belongs to fan delta glutenite deposit, typical conglomerate reservoir is developed. The dissolution pores are the dominated reservoir space, and its development degree

Abstract In this work, the influence of NaCl on natural sweet and sour gas hydrate formation in the pressure of 115 bar and isothermal conditions (8 °C) have been compared. Salt concentration in the experiments was in the range of 1-7 wt% and the inhibitor was used at a constant concentration of 0.5 wt%. The results show that the presence of salt has been more effective on inhibition time, hydrate

Abstract Excessive water production by high temperature (>140 °C) horizontal gas wells sharply decreases productivity. To date, no effective water shutoff agent has been developed to address this problem. In this study, a nanoparticle-reinforced active oil system that can be spontaneously emulsified under Tahe Formation conditions was constructed. The nanoparticles enhanced the water shutoff performance

Abstract In this work, phase-field method is used to develop a numerical model to simulate two-phase flow through a heterogeneous fractured porous medium. Various sensitivity analyses were performed to assess the impact of wettability, fracture aperture, interfacial tension, and water injection velocity on the displacement process. It was observed that the water mass imbibed into the matrix block varies

Abstract In this article, the effect of pulsating parameters on fractures extension was studied by using the cohesive element method and employed Abaqus as the platform for the simulations. The parameters such as injection rate, peak amplitude, approaching angle, in situ stress, and the natural fracture cementing strength were the focus of this study. The results of the simulations show that the fracture

Abstract This work is aimed at predicting the amount of residue coke and the temperature of operating mode of the regenerator, depending on the initial technological conditions of the process during regeneration of catalyst coked at various degrees (0.4–0.6% wt.). Numerical studies were performed using a mathematical model that takes into account the physicochemical regularities of the regeneration

A series of kinetics and combustion tube experiments were conducted to investigate the combustion characteristics and performance of in situ combustion (ISC) process for offshore heavy oils. Then, simulation studies were carried out to evaluate the performance of the ISC process in a typical offshore heavy oil reservoir. The results showed that higher heating rates resulted in a shift in the thermogravimetry

The theory of “secondary-tertiary integrated” enhanced oil recovery (EOR) was investigated. Models and methods for estimating the secondary water-flooding recovery, tertiary chemical-flooding recovery and “secondary-tertiary integrated” EOR were established, respectively. The results indicate that the ultimate recovery factor of “secondary-tertiary integrated” EOR is greater than the aggregation of

In this work, variations of heavy oil asphaltenes’ oxidation reactions under different conditions were investigated. By IR spectroscopy was shown a predominant destruction of occluded and adsorbed compounds in asphaltenes when using KIO3 and NaIO4 as oxidizing agents. In the case of CH3COOH/H2O2 and KMnO4 was determined the destruction of asphaltenes supermolecules with a formation of carboxyl groups

Abstract Precipitation and deposition of paraffin wax in pipelines and tubing are critical complications in the development of crude oil in oil and gas industry. Most new information on paraffin wax is dispersed in literature or exists in crania of experts like tacit knowledge. This review paper aims at disseminate the information; bridge some knowledge-gaps by giving a comprehensive review of chemistry

This research aims to explore the effects of saturates, aromatics, resins and asphaltenes (SARA) fractions on the heavy crude oil pyrolysis behavior. The results showed that resins and asphaltenes had more pyrolysis residues (22.04% and 45.66%) relative to other samples. However, no residue was found after pyrolysis reactions when the oil mixed with SARA fractions. In addition, high temperature pyrolysis

A series of experiments were performed to study the influence of initial pressures and pressure drop rates on the amount of lost gas during the coring process. The change laws of cumulative gas production and gas production rate were investigated. The proportion changes of lost gas, desorbed gas, and residual gas were analyzed. The results show that the cumulative gas production can be divided into

A 12-lumped reaction network for heavy oil catalytic cracking including 54 reaction paths is established according to the catalytic cracking reaction mechanism, clean gasoline, and light olefins production. The model kinetic parameters were calculated by Runge-Kutta method and BFGS based on the data from Davison Circulating Riser lab device and Python platform. The verification of the model parameters

Liquid hydrocarbons obtained from the pyrolysis of polypropylene and polystyrene were used as diluents to reduce the viscosity of a Mexican heavy crude oil of 10.6°API. Blends of oil and diluents were formulated with fractions of 5, 10 and 15 vol% of diluent. Viscosity results were plotted as a function of temperature and diluent volume fractions. The degree of viscosity reduction at room temperature

This study aims to develop a grid-based smart proxy model (G-SPM) for water flooding enhancement under different injection/production scenarios. The contribution of this work is combining experimental design and data mining techniques to prepare a high-quality database and introducing a hyper-feature to incorporate flow physics into database. The proxy was constructed by training a sequential neural

A commercially available anti-agglomerant (AA) was evaluated in water-in-crude oil (W/CO) emulsions at different water cut. The injection of an AA to an emulsion affects the induction time and rate of hydrate formation. When AA was injected before emulsification, AA performed better due to the higher number of AA molecules at the hydrate surface has been increased. The transition from stable a W/CO

Abstract Based on the physico-chemical regularities, the unsteady mathematical model of the diesel fuel catalytic dewaxing process was developed. The influence of the raw materials composition and flow rate on the catalyst deactivation degree, product output and cold filter plugging point was shown. It was established, that while producing low-freezing diesel fuel, the higher the aromatic content in

One of the major challenges of microwave assisted EOR is the composition of produced liquid and gases. In this present contribution, heavy oil from one of Chinese oil field were exposed to time variant microwave radiation until 18 min. Experimental results illustrates that rapid increase in the gas flow rate was observed between 3 and 12 min radiation and after 12 min radiation, this value tends to

In order to increase the efficiency of microbiological methods of influencing the formation and use them in formations having conditions, which are unfavorable for microorganism activities, a new microbiological method of oil recovery increase was developed in which a rim of low-saline flush fluid was used prior to the injection of organic substrate. As an organic substrate, a composition of two types

Abstract Static Dissipater Additive (SDA) is conductivity improver additive that is added to low sulfur fuels to avoid sudden increase in conductivity that may occur during transfer/pumping of fuel. Due to surface active nature, SDA dosage may deplete with time. The monitoring of concentration of SDA is very critical and is carried out using conductivity measurement as per ASTM D2624. In this study

This study investigated the relationship between chemical and physical or rheological properties of asphalt binders during aging. Two types of base asphalt binders and their SBS modified asphalt binders were chosen. Results show that carbonyl index (IC=O) or sulfoxide index (IS=O) for base asphalt binders has the higher correlation coefficient square (R2) with rheological properties than physical properties

In this work, the efficiency of CO2-foam injection for enhanced oil recovery (EOR) is investigated. Six floods were performed on sand pack columns. Pure water injection, WAG injection and simultaneous injection of CO2 and surfactant solution with various concentrations were conducted. Notable difference was observed between oil production in secondary surfactant assisted WAG and other injection scenarios

The saturated and aromatic hydrocarbon maturity parameters of shale from a salt lake basin were studied. The results show that the most familiar maturity parameters such as tricyclic terpane/hopane, Ts/Tm, sterane 20S/(20S + 20R), ββ/(ββ + αα), MPI1, MPI2, MPI3, PAI-1, and triaromatic steroid (І)/triaromatic steroid (І+ІІ), are not applicable for oil and source rock from saline lakes. The ratio of

In this paper, CO2 assisted steam flooding technique was proposed to further enhance heavy oil recovery after steam flooding. PVT tests and 3D model oil displacing experiment were conducted to investigate enhancing oil recovery (EOR) mechanisms and oil displacing performance. The results indicated that CO2 dissolving in heavy oil could induce oil swelling, reduce oil relative density, and reduce oil

The increase in global energy demand for crude oil has encouraged a huge growth in crude oil production worldwide. The flow behavior of crude oil poses many problems when transported by pipeline over long distances under different environmental conditions. Rheological study of crude oil is necessary to better understand its behavior and thus contribute to its proper transportation. In order to obtain

The average total organic carbon (TOC) content of Chang 91 source rocks is 4.85%, and the main kerogen type is II1, and the average pyrolysis peak temperature is 452 °C in Zhidan-Ansai area, Ordos Basin. These show that Chang 91 source rocks have reached good to excellent level and peak hydrocarbon generation stage. Chang 91 source rocks were formed in semi-deep lacustrine sedimentary environments

To investigate the effect of bitumen physicochemical and thermodynamic parameters on its cohesive properties, 9 asphalt binders from different refineries were used. Chemical constituents, molecular weight distribution as well as thermodynamic parameters of asphalt were obtained. Peel test was applied to evaluate the cohesive properties within bitumen. The relationship between these parameters was investigated

In thermal de-asphalting procedure, where asphaltene particles are aggregated through heating crude oil at an elevated temperature, predicting the asphaltene particles’ diameter is of major importance. In this study, thermal de-asphalting process is modeled using adaptive neuro fuzzy inference system by considering isolating temperature, crude oil API and asphaltene content as inputs to predict asphaltene

A natural hydrogen donor, i.e., a subfraction of the coker gas oil, was used in thermal upgrading of the Venezuela extra-heavy oil. The role of hydrogen donor was quantitatively studied by a combination of thermogravimetric analysis and differential scanning calorimetry. The hydrogen donation was clearly evidenced and reliably evaluated by comparing the experimental and calculated thermal parameters

The purpose is to clarify the effect of warm-mix modifier on rheological properties of SBS warm-mix modified asphalt and its viscosity reduction mechanism. Different types of SBS warm-mix modified asphalt were prepared. The effects of modifier content and temperature on the rheological properties of SBS warm-mix modified asphalt were assessed. The viscosity reduction mechanism of SBS warm-mix modified

The performance of both ebullated bed H-Oil vacuum residue (VR) hydrocracking and fluid catalytic cracking (FCC) of vacuum gas oils (VGO) is interrelated. The increase of H-Oil unit reaction temperature maximizes VR conversion and augments the aromaticity and density of the hydrocracked heavy oils. The FCC of VGO blends that contain more aromatic H-Oil VGOs is featured by a lower VGO conversion. It

Steam injection is attracting a considerable interest in terms of EOR. In this work the oil-saturated sandstones and their extracts (Ashalcha field) were subjected to hydrothermal heating in the presence of iron oxide (II, III) nanoparticles in an autoclave at a 200 °C and 250 °C for 24 hours. SARA analysis revealed that the destruction of resins and asphaltenes is observed after thermo-catalytic treatment

This work is aimed to investigate the effect of CO2/CH4 solvent and N2/CH4 solvent injection on phase behaviors of condensate in DZT reservoir. The results indicate that CO2/CH4 flooding is vaporizing-gas drive when the mole fraction of CO2 is below 0.8, and it becomes condensing-gas drive with the mole fraction of CO2 greater than 0.8. To lower the minimum miscible pressure of multiple contact miscibility

Carbonium ion can be generated easier when low-carbon alcohols are added to hydrocracking tail oil, which initiate the cracking reaction of macromolecular n-paraffin. So the yield of lube oil base oil increases, while that of paraffin decreases, but the total yield of the two products increases. When the low-carbon alcohol is added to the raw oil for non-hydrodewaxing reaction of hydrocracking tail

A series of NiO–MoO3 promoted Pt/ZrO2–TiO2–Al2O3 catalysts were investigated in the cracking reactions of n-decane under supercritical conditions. The results show that the addition of NiO could facilitate the formation of strong acid sites, which are contributed to improving the cracking performance. The catalyst with 6.0 wt.% NiO shows the highest catalytic cracking activity among all catalysts,