scholarly journals Determination of Residual Oil Distribution after Water Flooding and Polymer Flooding

2013 ◽  
Vol 5 (8) ◽  
pp. 2642-2647
Author(s):  
Yining Wang ◽  
Xiaodong Wu ◽  
Fengpeng Lai ◽  
Zhaopeng Yang ◽  
Man Teng
2011 ◽  
Vol 12 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Muhammad Taufiq Fathaddin ◽  
Asri Nugrahanti ◽  
Putri Nurizatulshira Buang ◽  
Khaled Abdalla Elraies

In this paper, simulation study was conducted to investigate the effect of spatial heterogeneity of multiple porosity fields on oil recovery, residual oil and microemulsion saturation. The generated porosity fields were applied into UTCHEM for simulating surfactant-polymer flooding in heterogeneous two-layered porous media. From the analysis, surfactant-polymer flooding was more sensitive than water flooding to the spatial distribution of multiple porosity fields. Residual oil saturation in upper and lower layers after water and polymer flooding was about the same with the reservoir heterogeneity. On the other hand, residual oil saturation in the two layers after surfactant-polymer flooding became more unequal as surfactant concentration increased. Surfactant-polymer flooding had higher oil recovery than water and polymer flooding within the range studied. The variation of oil recovery due to the reservoir heterogeneity was under 9.2%.


Author(s):  
Fengqi Tan ◽  
Changfu Xu ◽  
Yuliang Zhang ◽  
Gang Luo ◽  
Yukun Chen ◽  
...  

The special sedimentary environments of conglomerate reservoir lead to pore structure characteristics of complex modal, and the reservoir seepage system is mainly in the “sparse reticular-non reticular” flow pattern. As a result, the study on microscopic seepage mechanism of water flooding and polymer flooding and their differences becomes the complex part and key to enhance oil recovery. In this paper, the actual core samples from conglomerate reservoir in Karamay oilfield are selected as research objects to explore microscopic seepage mechanisms of water flooding and polymer flooding for hydrophilic rock as well as lipophilic rock by applying the Computed Tomography (CT) scanning technology. After that, the final oil recovery models of conglomerate reservoir are established in two displacement methods based on the influence analysis of oil displacement efficiency. Experimental results show that the seepage mechanisms of water flooding and polymer flooding for hydrophilic rock are all mainly “crawling” displacement along the rock surface while the weak lipophilic rocks are all mainly “inrushing” displacement along pore central. Due to the different seepage mechanisms among the water flooding and the polymer flooding, the residual oil remains in hydrophilic rock after water flooding process is mainly distributed in fine throats and pore interchange. These residual oil are cut into small droplets under the influence of polymer solution with stronger shearing drag effect. Then, those small droplets pass well through narrow throats and move forward along with the polymer solution flow, which makes enhancing oil recovery to be possible. The residual oil in weak lipophilic rock after water flooding mainly distributed on the rock particle surface and formed oil film and fine pore-throat. The polymer solution with stronger shear stress makes these oil films to carry away from particle surface in two ways such as bridge connection and forming oil silk. Because of the essential attributes differences between polymer solution and injection water solution, the impact of Complex Modal Pore Structure (CMPS) on the polymer solution displacement and seepage is much smaller than on water flooding solution. Therefore, for the two types of conglomerate rocks with different wettability, the pore structure is the main controlling factor of water flooding efficiency, while reservoir properties oil saturation, and other factors have smaller influence on flooding efficiency although the polymer flooding efficiency has a good correlation with remaining oil saturation after water flooding. Based on the analysis on oil displacement efficiency factors, the parameters of water flooding index and remaining oil saturation after water flooding are used to establish respectively calculation models of oil recovery in water flooding stage and polymer flooding stage for conglomerate reservoir. These models are able to calculate the oil recovery values of this area controlled by single well control, and further to determine the oil recovery of whole reservoir in different displacement stages by leveraging interpolation simulation methods, thereby providing more accurate geological parameters for the fine design of displacement oil program.


2014 ◽  
Vol 1010-1012 ◽  
pp. 1735-1739
Author(s):  
Feng Run Zhang ◽  
Ai Hua Guo ◽  
Huai En Cai

Because of the high heterogeneity, late water flooding and irregular well network, the distribution law of residual oil reserve in Chang 6 reservoir becomes much complicated. Combining the geology with dynamics of the reservoir, volumetric and formation coefficient methods are adapted to calculated the residual reserves, and then the distribution laws and controlling factors are analyzed. The results indicate that: there are still large amounts of residual reserve in main layer Chang 622; the residual reserve can be classified into three kinds, Class I and class II are distributed concentrative in main layer; the controlling factors include property, sedimentary facies, heterogeneity, well network controlling and geological structure and so on. Finally, according to the distribution laws and controlling factors, targeted measures are proposed. The studying results provide well foundations for improving recovery of residual oil reserves and the total recovery of the reservoir.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xuechao Liu ◽  
Dazhong Ren ◽  
Fengjuan Dong ◽  
Junxiang Nan ◽  
Ran Zhou

The character of residual oil formed during water flooding, one important technique to enhance oil recovery, is helpful to further study permeability and recovery in tight sandstone oil reservoirs. In this paper, we take a tight sandstone reservoir in Ordos Basin as the research object and use in situ displacement X-CT scanning technology to analyze the dynamic characteristics of oil during water flooding. Firstly, core pore radius and oil storage space radius were measured from digital cores which are acquired in different water flooding stages by X-CT scanning technology. Secondly, analytical and evaluation methods were established to describe fluid distribution in the pore space of the core in different water flooding stages based on curve similarity. Finally, by numerical results, we analyzed the oil distribution features in the process of water flooding for core samples. In this paper, the oil distribution characteristics during water flooding are revealed based on digital core analysis. Also, a quantitative evaluation method is given to provide theoretical guidance.


2012 ◽  
Vol 616-618 ◽  
pp. 126-132 ◽  
Author(s):  
Hua Bin Wei ◽  
Shang Ming Shi ◽  
Pan Zhao ◽  
Dong Kai Huo ◽  
Wan Zhen Zhu

The high water cut stage on the residual oil distribution regularity in late development stage of oilfield is difficult in Daqing oilfield, North West Water Flooding fine demonstration zone development time is long, well under the complicated characteristic, adopts phase control of three-dimensional geological modeling and the method of reservoir numerical simulation in the demonstration zone, structural features and sedimentary characteristics of based on the establishment of demonstration zone, three-dimensional geological model. Through the application of fine reservoir numerical simulation method for the numerical simulation of remaining oil, and a summary of the demonstration zone of residual oil distribution law and cause of formation, provides reliable basis for the next step of oilfield development adjustment.


Author(s):  
Muhammad Taufiq Fathaddin ◽  
Kartika Fajarwati Hartono ◽  
Trijana Kartoatmodjo

<em>In this paper, a numerical study was conducted to investigate the effect of spatial heterogeneity of multiple porosity fields on oil recovery, residual oil saturation,   polymer retained, and polymer adsorption. The generated porosity fields were applied to UTCHEM for simulating polymer and water flooding in heterogeneous two-layered porous media. From the analysis, the increase of reservoir heterogeneity resulted in higher polymer retention and lower polymer adsorption. In general, polymer flooding results in more balance residual oil saturation in the upper and lower layer than water flooding. This indicated that the vertical sweep efficiency of polymer flooding was better than water flooding. Residual oil saturation ratio between layers after water or polymer flooding was about equal along with the increase of reservoir heterogeneity. Spatial heterogeneity of multiple porosity fields had only a small effect on recovery factor. The variation of the recovery factor of polymer and water flooding due to the reservoir heterogeneity was under 1%</em>.


Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3732 ◽  
Author(s):  
Yaohao Guo ◽  
Lei Zhang ◽  
Guangpu Zhu ◽  
Jun Yao ◽  
Hai Sun ◽  
...  

Water flooding is an economic method commonly used in secondary recovery, but a large quantity of crude oil is still trapped in reservoirs after water flooding. A deep understanding of the distribution of residual oil is essential for the subsequent development of water flooding. In this study, a pore-scale model is developed to study the formation process and distribution characteristics of residual oil. The Navier–Stokes equation coupled with a phase field method is employed to describe the flooding process and track the interface of fluids. The results show a significant difference in residual oil distribution at different wetting conditions. The difference is also reflected in the oil recovery and water cut curves. Much more oil is displaced in water-wet porous media than oil-wet porous media after water breakthrough. Furthermore, enhanced oil recovery (EOR) mechanisms of both surfactant and polymer flooding are studied, and the effect of operation times for different EOR methods are analyzed. The surfactant flooding not only improves oil displacement efficiency, but also increases microscale sweep efficiency by reducing the entry pressure of micropores. Polymer weakens the effect of capillary force by increasing the viscous force, which leads to an improvement in sweep efficiency. The injection time of the surfactant has an important impact on the field development due to the formation of predominant pathway, but the EOR effect of polymer flooding does not have a similar correlation with the operation times. Results from this study can provide theoretical guidance for the appropriate design of EOR methods such as the application of surfactant and polymer flooding.


Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Huiying Zhong ◽  
Qiuyuan Zang ◽  
Hongjun Yin ◽  
Huifen Xia

With the growing demand for oil energy and a decrease in the recoverable reserves of conventional oil, the development of viscous oil, bitumen, and shale oil is playing an important role in the oil industry. Bohai Bay in China is an offshore oilfield that was developed through polymer flooding process. This study investigated the pore-scale displacement of medium viscosity oil by hydrophobically associating water-soluble polymers and purely viscous glycerin solutions. The role and contribution of elasticity on medium oil recovery were revealed and determined. Comparing the residual oil distribution after polymer flooding with that after glycerin flooding at a dead end, the results showed that the residual oil interface exhibited an asymmetrical “U” shape owing to the elasticity behavior of the polymer. This phenomenon revealed the key of elasticity enhancing oil recovery. Comparing the results of polymer flooding with that of glycerin flooding at different water flooding sweep efficiency levels, it was shown that the ratio of elastic contribution on the oil displacement efficiency increased as the water flooding sweep efficiency decreased. Additionally, the experiments on polymers, glycerin solutions, and brines displacement medium viscosity oil based on a constant pressure gradient at the core scale were carried out. The results indicated that the elasticity of the polymer can further reduce the saturation of medium viscosity oil with the same number of capillaries. In this study, the elasticity effect on the medium viscosity oil interface and the elasticity contribution on the medium viscosity oil were specified and clarified. The results of this study are promising with regard to the design and optimum polymers applied in an oilfield and to an improvement in the recovery of medium viscosity oil.


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