scholarly journals Recent Approaches, Catalysts and Formulations for Enhanced Recovery of Heavy Crude Oils

Author(s):  
Umar Gaya

Crude oil deposits as light/heavy form all over the world. With the continued depletion of the conventional crude and reserves trending heavier, the interest to maximise heavy oil recovery continues to emerge in importance. Ordinarily, the traditional oil recovery stages leave behind a large amount of heavy oil trapped in porous reservoir structure, making the imperative of additional or enhanced oil recovery (EOR) technologies. Besides, the integration of downhole in-situ upgrading along with oil recovery techniques not only improves the efficiency of production but also the quality of the produced oil, avoiding several surface handling costs and processing challenges. In this review, we present an outline of chemical agents underpinning these enabling technologies with a focus on the current approaches, new formulations and future directions.

2012 ◽  
Vol 608-609 ◽  
pp. 1428-1432 ◽  
Author(s):  
Wen Long Qin ◽  
Zeng Li Xiao

The aquathermolysis of Shengli heavy oil during steam stimulation was studied by using a new oil-soluble catalyst for the reaction in this paper. The laboratory experiment shows that the viscosity reduction ratio of heavy oil is over 75% at the circumstances of 200°C, 24 hs, 0.3 % catalyst solution. The viscosity of upgraded heavy oil is changed from 25306mPa•s to 6175mPa•s at 50°C. The chemical and physical properties of heavy oil both before and after reaction were studied by using column chromatography (CC) analysis and elemental analysis (EL). The percentage of saturated hydrocarbon、aromatic hydrocarbon and H/C increased, and resin、asphalt and the amount of element of S,O and N decreased after the aquathermolysis. The changes of the composition and structure of the heavy oil can lead to the viscosity reduction and the improvement the quality of heavy oil. The results are very useful for the popularization and application of the new technology for the in situ upgrading of heavy oil by aquathermolysis.


2018 ◽  
Vol 69 (10) ◽  
pp. 2669-2676
Author(s):  
Gheorghe Branoiu ◽  
Tudora Cristescu ◽  
Iulian Nistor

Developing and producing of the heavy crude oil involved significant economic and technological challenges. The oil industry ability to prospect and capitalize the huge world heavy oil resources both economically and environmentally friendly will be crucial in helping meet future energy needs. Thermal oil recovery is one of the three types of techniques belonging to Enhanced Oil Recovery. It is applied for increasing the cumulative of crude oil that can be produced in an oil field. One of the oldest thermal oil recovery is in-situ combustion or fireflooding applied for the first time about 100 years ago. Despite in-situ combustion has not found widespread acceptance among operators like other thermal processes (such as steam injection), analysis of the successful projects indicates that the process is applicable to a wide range of oil reservoirs, especially to heavy crude oils. An important monitoring parameter of thermal oil recovery process is represented by thermal regime especially in heavy oil fields in which a high-temperature regime must be occur as the in-situ combustion to be successful. In the paper the authors are using thermal analysis (thermogravimetric and thermodifferential analysis) for investigation of the thermal regime involved in the production process of an oil reservoir by in-situ combustion.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Chen Li ◽  
Lu Su ◽  
Qiuye Li ◽  
Xiaodong Wang ◽  
Xiaohong Li ◽  
...  

The important key of heavy oil efficient exploring is to decrease the viscosity and increase the flowability. Solid acid catalyst is one of the commonly used catalysts to reducing the viscosity of heavy oil, but good dispersion in oil phase and better catalytic activity are difficult to achieve. Herein, ZrO2-TiO2was selected as the fundamental catalyst because of its superior solid superacid properties, and CTAB was selected as the surfactant package coat to help enhance catalytic activity. The as-prepared catalysts were characterized systematically by TEM, XRD, FTIR, and N2adsorption-desorption isotherms measurement. The reduction efficiency of the heavy oil viscosity achieved as high as 66.3% at 180°C. At the same time, the portion of asphaltenes and resins slipped down by 4.93% and 3.78%, respectively, while saturated and aromatic hydrocarbon component increased by 5.37% and 3.26%, respectively, indicating that our catalyst showed a good activity for reducing the viscosity and improving the quality of heavy crude oil.


2021 ◽  
Author(s):  
Alexey V. Vakhin ◽  
Irek I. Mukhamatdinov ◽  
Firdavs A. Aliev ◽  
Dmitriy F. Feoktistov ◽  
Sergey A. Sitnov ◽  
...  

Abstract A nickel-based catalyst precursor has been synthesized for in-situ upgrading of heavy crude oil that is capable of increasing the efficiency of steam stimulation techniques. The precursor activation occurs due to the decomposition of nickel tallate under hydrothermal conditions. The aim of this study is to analyze the efficiency of in-situ catalytic upgrading of heavy oil from laboratory scale experiments to the field-scale implementation in Boca de Jaruco reservoir. The proposed catalytic composition for in-reservoir chemical transformation of heavy oil and natural bitumen is composed of oil-soluble nickel compound and organic hydrogen donor solvent. The nickel-based catalytic composition in laboratory-scale hydrothermal conditions at 300°С and 90 bars demonstrated a high performance; the content of asphaltenes was reduced from 22% to 7 wt.%. The viscosity of crude oil was also reduced by three times. The technology for industrial-scale production of catalyst precursor was designed and the first pilot batch with a mass of 12 ton was achieved. A «Cyclic steam stimulation» technology was modified in order to deliver the catalytic composition to the pay zones of Boca de Jaruco reservoir (Cuba). The active forms of catalyst precursors are nanodispersed mixed oxides and sulfides of nickel. The pilot test of catalyst injection was carried out in bituminous carbonate formation M, in Boca de Jaruco reservoir (Cuba). The application of catalytic composition provided increase in cumulative oil production and incremental oil recovery in contrast to the previous cycle (without catalyst) is 170% up to date (the effect is in progress). After injection of catalysts, more than 200 samples from production well were analyzed in laboratory. Based on the physical and chemical properties of investigated samples and considering the excellent oil recovery coefficient it is decided to expand the industrial application of catalysts in the given reservoir. The project is scheduled on the fourth quarter of 2021.


2021 ◽  
pp. 1-13
Author(s):  
Melek Deniz Paker ◽  
Murat Cinar

Abstract A significant portion of world oil reserves reside in naturally fractured reservoirs and a considerable amount of these resources includes heavy oil and bitumen. Thermal enhanced oil recovery methods (EOR) are mostly applied in heavy oil reservoirs to improve oil recovery. In situ combustion (/SC) is one of the thermal EOR methods that could be applicable in a variety of reservoirs. Unlike steam, heat is generated in situ due to the injection of air or oxygen enriched air into a reservoir. Energy is provided by multi-step reactions between oxygen and the fuel at particular temperatures underground. This method upgrades the oil in situ while the heaviest fraction of the oil is burned during the process. The application of /SC in fractured reservoirs is challenging since the injected air would flow through the fracture and a small portion of oil in the/near fracture would react with the injected air. Only a few researchers have studied /SC in fractured or high permeability contrast systems experimentally. For in situ combustion to be applied in fractured systems in an efficient way, the underlying mechanism needs to be understood. In this study, the major focus is permeability variation that is the most prominent feature of fractured systems. The effect of orientation and width of the region with higher permeability on the sustainability of front propagation are studied. The contrast in permeability was experimentally simulated with sand of different particle size. These higher permeability regions are analogous to fractures within a naturally fractured rock. Several /SC tests with sand-pack were carried out to obtain a better understanding of the effect of horizontal vertical, and combined (both vertical and horizontal) orientation of the high permeability region with respect to airflow to investigate the conditions that are required for a self-sustained front propagation and to understand the fundamental behavior. Within the experimental conditions of the study, the test results showed that combustion front propagated faster in the higher permeability region. In addition, horizontal orientation almost had no effect on the sustainability of the front; however, it affected oxygen consumption, temperature, and velocity of the front. On the contrary, the vertical orientation of the higher permeability region had a profound effect on the sustainability of the combustion front. The combustion behavior was poorer for the tests with vertical orientation, yet the produced oil AP/ gravity was higher. Based on the experimental results a mechanism has been proposed to explain the behavior of combustion front in systems with high permeability contrast.


2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Chuan Lu ◽  
Wei Zhao ◽  
Yongge Liu ◽  
Xiaohu Dong

Oil-in-water (O/W) emulsions are expected to be formed in the process of surfactant flooding for heavy oil reservoirs in order to strengthen the fluidity of heavy oil and enhance oil recovery. However, there is still a lack of detailed understanding of mechanisms and effects involved in the flow of O/W emulsions in porous media. In this study, a pore-scale transparent model packed with glass beads was first used to investigate the transport and retention mechanisms of in situ generated O/W emulsions. Then, a double-sandpack model with different permeabilities was used to further study the effect of in situ formed O/W emulsions on the improvement of sweep efficiency and oil recovery. The pore-scale visualization experiment presented an in situ emulsification process. The in situ formed O/W emulsions could absorb to the surface of pore-throats, and plug pore-throats through mechanisms of capture-plugging (by a single emulsion droplet) and superposition-plugging or annulus-plugging (by multiple emulsion droplets). The double-sandpack experiments proved that the in situ formed O/W emulsion droplets were beneficial for the mobility control in the high permeability sandpack and the oil recovery enhancement in the low permeability sandpack. The size distribution of the produced emulsions proved that larger pressures were capable to displace larger O/W emulsion droplets out of the pore-throat and reduce their retention volumes.


2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Ali Alarbah ◽  
Ezeddin Shirif ◽  
Na Jia ◽  
Hamdi Bumraiwha

Abstract Chemical-assisted enhanced oil recovery (EOR) has recently received a great deal of attention as a means of improving the efficiency of oil recovery processes. Producing heavy oil is technically difficult due to its high viscosity and high asphaltene content; therefore, novel recovery techniques are frequently tested and developed. This study contributes to general progress in this area by synthesizing an acidic Ni-Mo-based liquid catalyst (LC) and employing it to improve heavy oil recovery from sand-pack columns for the first time. To understand the mechanisms responsible for improved recovery, the effect of the LC on oil viscosity, density, interfacial tension (IFT), and saturates, aromatics, resin, and asphaltenes (SARA) were assessed. The results show that heavy oil treated with an acidic Ni-Mo-based LC has reduced viscosity and density and that the IFT of oil–water decreased by 7.69 mN/m, from 24.80 mN/m to 17.11 mN/m. These results are specific to the LC employed. The results also indicate that the presence of the LC partially upgrades the structure and group composition of the heavy oil, and sand-pack flooding results show that the LC increased the heavy oil recovery factor by 60.50% of the original oil in place (OOIP). Together, these findings demonstrate that acidic Ni-Mo-based LCs are an effective form of chemical-enhanced EOR and should be considered for wider testing and/or commercial use.


2019 ◽  
Vol 239 ◽  
pp. 1190-1211 ◽  
Author(s):  
Xiaohu Dong ◽  
Huiqing Liu ◽  
Zhangxin Chen ◽  
Keliu Wu ◽  
Ning Lu ◽  
...  

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