Viscosity Of Crude Oil Research Articles

Parametric optimization of in-situ heavy oil upgrading using simultaneous microwave radiation and magnetic nanohybrids via Taguchi approach

This study investigated the effect of Fe3O4, Fe3O4-MWCNT, and Fe3O4-NiO nanohybrids on the in-situ heavy oil upgrading using microwave radiation through the Taguchi DOE method. The nanohybrids were synthesized via a co-precipitation method and were characterized using different analyses. Three numerical parameters, including the concentration of nanohybrids, power and time of microwave radiation, and a categorical factor including the type of the nanohybrids, were considered in a DOE plan. Results showed that electrical permeability, loss tangent, and electrical conductivity of Fe3O4-MWCNT nanohybrids are higher than other nanoparticles. Nanoparticle’s concentration (at 0.5 wt%) had the most significant effect on reducing the viscosity and increasing the API degree of crude oil. All three system responses, including viscosity, API, and oil sample temperature, were raised by increasing the power of microwaves from 400 W to 1200 W. The lowest viscosity of crude oil was obtained at low irradiation times (8 min.). The optimal conditions for achieving the greatest reduction in crude oil viscosity were a combination of using 0.5 wt% of Fe3O4-MWCNT nanohybrid under 8 min of 400 W microwave radiation. Finally, it found that microwave radiation has made the oil sample lighter and reduced the sulfur content in the crude oil. So, the use of Fe3O4-MWCNT nanohybrid has reduced the sulfur content in the primary crude oil sample by 16.6%.

Recyclable magnetic carbon foams possessing voltage-controllable electromagnetic shielding and oil/water separation

Lightweight carbon foams with high-performance electromagnetic interference (EMI) shielding have attracted extensive attentions. However, it is challenging for researchers to effectively regulate the EMI shielding of carbon foams independent on shield's thickness. Herein, we proposed a macroscopic magnetic carbon foams through a chemical engineering strategy under the synergies of nickel ion reduction and in-situ growth of carbon nanotubes on carbon frameworks derived from carbonized woods. The macroscopic magnetic carbon foams present high-performance EMI shielding with absorption-dominant mechanism, and the removal of oil pollutants for water purification. Magnetic properties favor the manipulation of oil absorption without direct mechanic contact. After burning, the magnetic carbon foams can be re-used in EMI shielding and oil absorbency. Furthermore, we used a novel electric voltage-driven strategy to upgrade EMI shielding performances of magnetic carbon foams. By the increase in applied voltages, the enhanced absorption-dominant EMI shielding and fast oil absorbency due to the decrease viscosity of crude oil could be simultaneously obtained. The strategy developed here may lead a new avenue toward the design of porous magnetic carbon foams with the enhanced voltage-driven multifunctionalities for practical applications.

Research and Application of Bottom Water Control and Suppression Technology by CO2 Huff-and-Puff

In order to solve the problems about rapid increasement rate of water cut and large production decline in bottom water heavy oil reservoir due to active bottom water and high crude oil viscosity, the research on CO2 huff-and-puff technology is carried out. The results showed that the mechanism of CO2 huff-and-puff was mainly to reduce the viscosity of heavy crude oil, carbonate reacted with bottom water and formed interlayer to achieve viscosity reduction and precipitation. The comprehensive water cut was decreased by 35%, and the average oil production of a single well was increased by 3∼4 times. Therefore, CO2 huff-and-puff technology was one of technologies about bottom water control and oil production stabilization, and it is of great significance to enhance oil production in heavy oil bottom water reservoirs.

Effects of oil properties on the formation of oil-particle aggregates at the presence of chemical dispersant in baffled flask tests

The formation of oil-particle aggregates (OPA) is the major sedimental pathway of spilled oil, which can bring great harm to both the benthic communities and marine environment. In this paper, effects of GM-2 chemical dispersant and oil properties on the formation of OPA was investigated by the EPA baffled flask test. The addition of dispersant can promote the formation of OPA from montmorillonite and five test oils obviously. With the increase of the dispersant dosage, the size of trapped oil in OPA increased and the density of OPA decreased. The dispersant can increase the kinematic viscosity of crude oil, and high viscosity of the oil is advantageous for the formation of OPA. The oil-seawater interfacial tension is reduced after the addition of dispersant, which makes oil dispersed into the water column easier. A kinematic equation of dispersed oil concentration attenuation was modified by introducing the oil property coefficient β. The modified empirical equation can calculate the mass of oil in sunken OPA in oil spill accidents.

Determination of Reasonable Bottom-Hole Pressure in Unconventional Tight Oil Reservoirs: A Field Case Investigation

Abstract The bottom-hole flow pressure is an important factor affecting the production of the unconventional tight oil well. The reasonable bottom-hole flow pressure has a positive effect on enhancing the production capacity of oilfields and improving the production efficiency of oilfield enterprises. Therefore, a robust method is proposed to determine the reasonable bottom-hole flow pressure in unconventional tight oil reservoirs, sharing the advantages of coupling geological feature and fluid flow behavior. In this method, the geological model and numerical reservoir simulation based on ECLIPSE software are developed firstly. The effects of the stress sensitivity, the PVT properties, permeability damage, fracturing fluid leak-off, and skin coefficient on the single-well productivity are then discussed. The reasonable variation range of the bottom-hole flow pressure in different production stages is then determined. Results show that crude oil viscosity, formation damage, and stress sensitivity are the most sensitive factors to the recovery degree. And, desirable tight oil production performance can be achieved with the application of the optimized bottom-hole pressure.

Newtonian and Non-Newtonian Viscosity of Waxy Crude Oils and Condensates: A Noncompositional Model

Newtonian and Non-Newtonian Viscosity of Waxy Crude Oils and Condensates: A Noncompositional Model

The influence of the viscosity of crude oil on liquid-dynamic noise characteristics in the volute shell of oil transfer pump

This paper aims to study the influence of the viscosity of crude oil on the liquid-dynamic noise characteristics using ANSYS Fluent. The RNG k-ɛ model is used for simulating the static pressure distribution characteristics of crude oil in the centrifugal pump. The LES S-L model is used for simulating the transient characteristics of crude oil in the centrifugal pump. The results show that the viscosity of crude oil is the primary factor affecting the static pressure distribution and the transient characteristics of crude oil in the centrifugal pump. The lower the viscosity of the crude oil is, the greater the change in static pressure is. The maximum static pressure peak appears nearby the tongue of oil transfer pump. The static pressure critical viscosity affecting the inner wall of the volute shell is 1728mPa.s. According to the viscosity test data provided by related literature, A 3-step mathematical characterization model is proposed to describe the relationship between the viscosity and the corresponding water content of crude oil. It can be used to compute the crude oil viscosity parameter as a given value in ANSYS Fluent program. The maximum relative deviation is 2.62%. A transmit method is proposed by heating up the pre-stable and post-stable crude oil twice to keep the viscosity constant in the whole progress of crude oil transmit. It will be beneficial to energy saving.

Modification of the viscosity of extra-heavy crude oil using aqueous extracts of common geranium (Pelargonium hortorum)

The transport of extra-heavy crude oil is a severe problem in the oil industry due to its viscosity, asphaltenes content, and tendency to precipitate. These crude oil's characteristics cause clogging of the pipes and increase production costs. One of the solutions for this problem is the addition of compounds that reduce the viscosity of crude oil and the self-aggregation of asphaltenes. In recent years, new ‘green’ additives have been investigated to replace the use of traditional and more toxic substances, such as toluene. In this study, new common geranium (Pelargonium hortorum) aqueous extracts were synthesized with 1, 5, and 10% (w/v). Its effect on the Mexican extra-heavy (8 °API) crude oil blend was analyzed in a shear rate range of 0.1–60 1/s and constant temperatures of 30, 40, and 50 °C. In addition, its pH, TDS, and EC were measured on days 1 and 15 after synthesis. These synthesized compounds were qualitatively determined using phytochemical analysis. The possible relationship between these compounds and the viscosity modification was analyzed. The results suggest that using these compounds as viscosity modifiers for extra-heavy crude oil could be promising, at higher concentrations in the range of 5–10% and for a temperature range of 40–50 °C, and for lower shear rates. The conclusions suggest further investigation of the common geranium aqueous extracts to understand its effect on crude oil properties.

Photothermal bio-based membrane via spectrum-tailoring and dual H-bonding networks strategies for seawater treatment and crude oil viscosity reduction

To reach global carbon neutralization, the use of clean energy and biomaterials has become a trend to reduce CO2 emission. With the increasing concerns about freshwater shortage and crude oil pollution, water purification and sewage treatment have become particularly urgent. Solar energy is an environment-friendly energy to mitigate freshwater shortage stress and reduce crude oil pollution. However, how to make solar energy applied to effectively drive freshwater generation and crude oil pollution remedy is crucial. Herein, the electrospun membrane was explored as sustainable matrix with desirable solar-to-thermal performance. The strategy of spectrum-tailoring was proposed to tailor bandgap energy of vanadium disulfide (VS2) for photothermal conversion promotion and interfacial evaporation efficiency. Inspired by mussel, dopamine was polymerized on surface of VS2 (VS2@PDA) for spectrum tailoring (Solar absorptance, α, is 89.34 %). Bandgap energy of the complex favorably decreased from 2.06 to 1.41 eV. Combining the dual H-bonding networks, water evaporation enthalpy of the membranes dramatically decreased from 2370 to 1990.2 J/g and the resulted evaporators showed excellent salt resistance, with evaporation rate of 1.40 kg m-2h−1 (enhancement factor is 2.032) and extraordinary cyclic evaporation performance. Additionally, sunflower-inspired tilting model was architectured to eliminate disturbance of sun irradiation incident angles for effective solar-driven interfacial generation. The resulted membrane effectively treated the seawater and decreased high viscosity of the super-viscous crude oil under the sun irradiation, thus showing great potential in seawater treatment and crude oil pollution remedy. The designs maximized utilization of solar energy and evaporation rates by treating seawater and reducing crude oil pollution without consuming additional energy, thus contributing to carbon neutralization. Therefore, the integration of dual H-bonding networks and spectrum-tailoring strategies would facilitate the structure-functional unification and desirable photothermal capabilities, and bring about an application potential in the development of composite evaporators for carbon neutralization.

Rheological behavior of crude oil and its dependence on the composition and chemical structure of oil components

In this article on the example of two crude oil with the same content of resins, asphaltene, and solid paraffin, it is shown that they have different rheological behavior at low shear rates. The chemical composition of crude oil's high molecular weight components (asphaltene and solid paraffin) was studied by EPR, IR spectroscopy, and chromatography. It is shown that their composition does not differ significantly. It was revealed that the reason for the different rheological behavior of the crude oils is the content of saturated and aromatic hydrocarbons. When the content of mono- and bi-aromatic hydrocarbons in crude oil increases, the degree of its non-Newton behavior increases. It is due to the formation of a coagulation structure in it. The data obtained have to take into account to predict crude oil viscosity when technologies for oil recovery and transportation developed.

Experimental study on wax removal and viscosity reduction of waxy crude oil by Ochrobactrumintermedium

To investigate the influence of microbial wax removal and viscosity reduction technologies on the fluidity of waxy crude oil, this study took the waxy crude oil from China's Daqing Oilfield as the experimental object for microbial wax removal and viscosity reduction experiment. First, utilizing standard strain screening and culture protocols, a high-efficiency microbial strain H-1 (Ochrobactrum intermedium) was proposed from in situ soil. The single factor experiment and multi-factor response surface analysis were then utilized to optimize the temperature, initial pH value of the medium, and NaCl mass concentration needed for the strain's growth. Oil displaced activity and emulsification tests were used to evaluate the biosurfactants produced by the metabolism of strain H-1, and Fourier transform infrared spectroscopy was used to identify the types of biosurfactants. Finally, the application effect of strain H-1 on wax removal and viscosity reduction of waxy crude oil were clarified through the wax crystal morphology, wax content, and viscosity of waxy crude oil. The research findings indicated that strain H-1 produced best at a temperature of 38.5 °C, pH value was 7.1 and the mass fraction of NaCl was 0.64%. The lipopeptide biosurfactant produced by strain H-1 can displace oil. Additionally, strain H-1 has a high emulsifying capacity, with a 61.25% emulsifying coefficient. After 7 days of treatment with the strain H-1, the wax crystal morphology of the waxy crude oil changed from a large-sized aggregated to a small-sized sparse condition, and the wax content of the waxy crude oil fell by 38.67%. The viscosity reduction rate of strain H-1 to waxy crude oil was consistently greater than 30% over the temperature range of 30–42 °C, with the greatest rate of 42.38% at 39 °C. The preceding results demonstrate that strain H-1 can degrade the wax components of waxy crude oil, lower the crude oil's low temperature viscosity, and then improve the crude oil's low-temperature fluidity.

Solar-assisted high-efficient cleanup of viscous crude oil spill using an ink-modified plant fiber sponge

Rapid and efficient clean-up of viscous crude oil spills is still a global challenge due to its high viscous and poor flowability at room temperature. The hydrophobic/oleophilic absorbents with three-dimensional porous structure have been considered as a promising candidate to handle oil spills. However, they still have limited application in recovering the high viscous oil. Inspired by the viscosity of crude oil depended on the temperature, a solar-heated ink modified plant fiber sponge (PFS@GC) is fabricated via a simple and environmentally friendly physical foaming strategy combined with in-situ ink coating treatment. After wrapping by the polydimethylsiloxane (PDMS), the modified PFS@GC (PFS@GC@PDMS) exhibits excellent compressibility, high hydrophobic (141° in water contact angle), solar absorption (> 96.0%), and oil absorptive capacity (12.0–27.8 g/g). Benefiting from the favorable mechanical property and photothermal conversion capacity, PFS@GC@PDMS is demonstrated as a high-performance absorbent for crude oil clean-up and recovery. In addition, PFS@GC@PDMS can also be applied in a continuous absorption system for uninterrupted recovering of oil spills on the water surface. The proposed solar-heated absorbent design provides a new opportunity for exploring biomass in addressing large-scale oil spill disasters.

Prediction Model for the Viscosity of Heavy Oil Diluted with Light Oil Using Machine Learning Techniques

Due to the presence of asphaltene, the flow assurance of high viscosity crude oil becomes more challenging and costly to produce in wellbores and pipelines. One of the most effective ways to reduce viscosity is to blend heavy oil with light oil. However, the viscosity measurement of diluted heavy crude is either time-consuming or inaccurate. This work aims to develop a more accurate viscosity model of diluted heavy crude based on machine learning techniques. A multilayer neural network is used to predict the viscosity of heavy oil diluted with lighter oil. The input data used in the training include temperature, light oil viscosity, heavy oil viscosity, and dilution ratio. In this modeling process, 156 datasets were retrieved from the available iterature of various heavy-oil fields in China. Part of the data (80%) is used to train the developed models using Adam optimizer algorithms, while the other part of the data (20%) is used to predict the viscosity of heavy oil diluted with lighter. The performance and accuracy of the machine learning models were tested and compared with the existing viscosity models. It was found that the new model can predict the viscosity of diluted heavy oil with higher accuracy, and it performs better than other models. The absolute average relative error is 10.44%, the standard deviation of the relative error is 8.45%, and the coefficient of determination is R2 = 0.95. The viscosity predicted by the neural network outperformed existing correlations by the statistical analysis used for the datasets available in the literature. Therefore, the method proposed in this paper can better estimate the viscosity of diluted heavy crude oil and has important promotion value.

Power ultrasound on asphalt viscoelastic behavior analysis

Petroleum asphalt, which is the residue left after the distillation of crude oil, meets the characteristics of a mature physics technology of ultrasonic disposal used to reduce the viscosity of crude oil and improve the oil recovery rate. In this study, we analyzed changes in the viscosity of change trend of molten asphalt during ultrasonic disposal tests based on the viscosity-temperature properties of asphalt. We also investigated the effects of ultrasonic vibration on the chemical properties of asphalt by conducting microscopic and chemical tests. The results showed the following: (1) ultrasonic irradiation generated by the circulating vibration and cavitation effect can effectively reduced the viscosity of asphalt according to the law of specificity; 2) the MSCR test data changes showed that the viscosity recovery of ultrasonic disposal of asphalt increased over time, and the results showed that ultrasonic vibration had short-term adhesion reduction characteristics of matrix asphalt; and (3) four-component analysis shows that: the asphalt decreased the heavy component and increased the light component content after ultrasonic disposal, indicating that ultrasound can lighten the asphalt, which can be used as a new asphalt warm mix technology.

Evaluation Model and Application of Shale Oil Production Efficiency Under Energy-Depleted Development Mode in Jimsar Sag

In order to reveal the shale oil production mechanism and production efficiency under the energy-depleted development mode, experiments on expulsion oil based on imbibition and elastic energy release under high temperature and pressure were carried out, and nuclear magnetic resonance on-line monitoring was used to observe the production characteristics of shale oil. The experimental results show that the imbibition-expulsion oil mainly occurs in the small-size pore-throat system. Under the condition of high temperature and pressure, the oil-expulsion efficiency is generally less than 2% affected by pore pressure, which is significantly different from the conventional imbibition experiment results. Although elastic-energy expulsion oil occurs in different sizes of pore-throat systems, the oil-expulsion efficiency in large size pore-throat systems is more sensitive to temperature. Overall, the total elastic-energy oil-expulsion efficiency is significantly positively correlated with reservoir physical properties, production differential pressure and temperature, and negatively correlated with crude oil viscosity. Comprehensively considering various geological factors affecting oil-expulsion efficiency, the shale oil production efficiency evaluation model under the energy-depleted development mode is constructed, and the movable oil porosity of shale oil development section in the study area is evaluated. The results show that there is a good positive correlation between movable oil porosity and oil production intensity. The movable oil porosity of dry layer is generally lower than 0.5% and that of poor oil layer is between 0.5% and 1.5%. When the movable oil porosity is between 1.5 and 2.5%, it can be determined as the type II oil layer, and for more than 2.5%, it is the type I oil layer. The single-well evaluation results show that the shale oil “sweet spots” of the Lucaogou Formation in Jimsar Sag are mainly distributed in P2l22−1∼ P2l22−3 and P2l12−1∼ P2l12−3, which is in good agreement with the current development status.

Experimental analyzing the effect of n-heptane concentration and angular frequency on the viscoelastic behavior of crude oil containing asphaltene

Asphaltene often produces problems in upstream and downstream sections of crude oil transportation and processing equipment. These issues are directly related to the asphaltene precipitation in transportation pipelines, separation columns, heat exchangers, and storage tanks. This research investigates the impact of angular frequency and n-heptane concentration on asphaltene precipitation and rheological behavior of two oil samples from the Mansouri oil field in Iran, i.e., 23 and 71. The viscosity tests revealed that these oil samples and their mixtures with n-heptane exhibit Newtonian behavior. Moreover, increasing the n-heptane concentration increases the asphaltene precipitation and dramatically decreases crude oil viscosity. The frequency tests revealed that the presence of n-heptane has an unfavorable effect on crude oil’s viscoelastic behavior. Therefore, it is necessary to find the optimum range of angular frequency and n-heptane concentration to minimize the asphaltene content of crude oil and provide them with appropriate viscoelastic behavior. Increasing the angular frequency continuously increases all oil samples’ loss modulus and strengthens their liquid-like manner. The experimental results confirmed that the angular frequency higher than 33.6 rad/s and 75% volume concentration of n-heptane is the best condition for the oil sample of 23. On the other hand, the angular frequency higher than 23.4 rad/s and 75% volume concentration of n-heptane is the best condition for the oil sample of 71. In these conditions, the oil samples of 23 and 71 not only have appropriate viscoelastic behavior, but they also experience 97.2% and 96.3% reductions in their viscosity, respectively.

Performance of thermophilic strain on the reduction of viscosity of crude oil under high pressure and high temperature conditions: Experiments and modeling

The matured reservoirs all over the world leads on the way to highly viscous crude oil. The heavy and waxy oil would act as an alternative to conventional reserves, only with the application of a technology to reduce the viscosity. This study aims to analyze the microbial activity on crude oil, and the synergetic effect of microbial interaction, pressure and temperature on viscosity. The reports on application of microorganisms on the viscosity reduction of crude oil are very rare at high temperature and high pressure environment. The application of Bacillus subtilis , a thermophilic bacterium for improving the flow properties of waxy crude oil is investigated at various temperatures and pressures in a high pressure cell. This study has been carried out to simulate the microbiological phenomenon occurring in the reservoir, when a bacteria is introduced for viscosity reduction. Bacillus subtilis could grow well from 0.1 to 5 MPa, and less growth was observed at 10 MPa. The maximum 52.1% of viscosity of crude oil was reduced at the pressure of 1 MPa, temperature of 50 °C, and at the shear rate of 1000 s −1 by microbial interaction. The implicit correlations as a function of pressure, temperature, and shear rate has been developed to predict the viscosity of crude oil during the microbial treatment. This work also proposed a new model incorporating the thermodynamic and microbial kinetics to estimate the viscosity of crude oil during the process of microbial degradation. The proposed model has provided satisfactory predictions when compared with the experimental values of degradation. All these findings demonstrate the influence and suitability of Bacillus subtilis in crude oil production and transportation. • Suitability of Bacillus subtilis at high temperature and pressure was explored. • Interaction of crude oil and Bacillus subtilis were examined for viscosity reduction. • Analyzed the synergetic effect of pressure and temperature on viscosity reduction. • Viscosity of crude oil was reduced by 52.1% at 1 MPa, 50 °C, and 1000 s −1 . • Proposed a model to predict viscosity during microbial degradation of crude oil.

Petroleum viscosity modeling using least squares and ANN methods

274 crude oils pertaining to the groups of extra light (gas condensates), light, medium, heavy, and extra heavy crude oils were characterized by true boiling point distillation, specific gravity and kinematic viscosity at 21.11 and 37.78 °C. Eight published regression empirical methods were examined for their capability of accurately predicting the crude oil viscosity. Among them the model of Kotzakoulakis and George was found to provide the lowest average absolute relative error (AARE) of 24.0% with AARE of 21.5% for the crude oils containing <30 wt% vacuum residue (VR) and AARE of 37.2% for the crude oils having >30 wt% VR. The model of Aboul-Seoud and Moharam exhibited the lowest AARE (16.3%) for the crude oils with <30 wt% VR. A new nonlinear regression model was developed that predicted the viscosity of the 274 crude oils with AARE of 19.5%, with AARE of 14.9% for the crude oils containing <30 wt% VR, and AARE of 42.0% for the crude oils having >30 wt% VR. Another model based on the artificial neural network (ANN) technique was developed. The ANN model predicted the viscosity of the 274 crude oils with AARE of 44.3%, with AARE of 50.2% for the crude oils with <30 wt% VR, and AARE of 13.9% for the crude oils containing >30 wt% VR. The combination of predicting the viscosity of crude oils having <30 wt% VR by the new nonlinear regression model with the predicting of viscosity of crude oils with >30 wt% VR by the ANN model provides of AARE of 14.9% of viscosity prediction for the entire data base of 274 crude oils.

Insights into Flow Improving for Waxy Crude Oil Doped with EVA/SiO2 Nanohybrids.

Nanohybrid materials can significantly inhibit wax deposition and improve the fluidity of crude oil. However, the mechanisms behind wax resolving, crystal modification, and flow improving are still unclear owing to the complexity of crude oil. Here, we compared the effect of ethylene vinyl acetate (EVA) and nanohybrids composed of EVA and SiO2 nanoparticles on wax crystallization and rheological behavior of Shengli waxy oil. Differential scanning calorimetry results indicate that SiO2 nanoparticles boost the efficiency of EVA for reducing the wax appearance temperature of waxy crude oil. Thermo X-ray diffraction characterization demonstrates that EVA/SiO2 nanohybrids cut down the crystal index of waxes, with the grain size of crystal cells decreased in (006) and (200) but increased in (110) cross sections. Polarized optical microscopy imaging reveals that EVA can modify the morphology of wax crystals to suppress the formation of wax gel, and nanohybrids serve as nucleuses to adsorb asphaltenes and resins, restraining the appearance of wax crystals. The rheological test shows that nanohybrids outperform EVA in decreasing the viscosity, inflection point, and yield stress of waxy crude oil. These findings help the understanding of flow improving by nanohybrid materials and offer guidelines for designing the new generation of wax inhibitors for safe transportation and flow assurance of waxy crude oil.

Viscosity reduction of heavy crude oil by co-heating with hydrothermal liquid product of cotton stalk

Abstract Hydrothermal process (HT) is an economical and simple method in upgrading agriculture wastes. The liquid product obtained from HT is interesting because of abundant active chemical group. The present work tried to co-heat the HT liquid product of cotton stalk (CS) with heavy crude oil to reduce its viscosity. The optimization study was performed to obtain the best condition of co-heating and mechanism study was completed by comparing the viscosity reduction efficiency and analyzing group composition of crude oil before and after co-heating with HT liquid products of CS, cellulose, hemicellulose and lignin. The results show that the crude oil viscosity reduced obviously after co-heating with CS-HT liquid product under the optimized condition (220°C, 1 h, 3 g treatment liquid, 30 ml crude oil). The preliminary mechanism study results suggest that the main function component of CS that cause viscosity reduction of heavy oil is lignin. The current work provides a new idea of lignocellulosic biomass upgrading and heavy crude oil viscosity reduction.