Mechanisms of Enhancing Recovery of the Superficial Heavy Oil Reservoir

2012 ◽  
Vol 550-553 ◽  
pp. 468-471
Author(s):  
Fu Sheng Zhang ◽  
Jian Ouyang ◽  
De Wei Wang ◽  
Xin Fang Feng ◽  
Li Qing Xu
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Water Flooding ◽  
Chemical Agent ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Heavy Oil Reservoir ◽  
Enhance Oil Recovery

The core displacement experiments show that displacement system containing chemical agent can enhance oil recovery by over 20% comparing to water flooding. Mechanisms by which chemical agent enhance oil recovery of heavy oil reservoir water flooding are: (1) improving mobility ratio by significantly decreasing viscosity of heavy oil, volumetric sweep efficiency is improved; (2) increasing capillary number by significantly decreasing oil-water interfacial tension, oil displacement efficiency is increased; (3) changing wettability of the rock surface from oil-wet to water-wet by significantly reducing the contact angle between displacement liquid and sandstone surface, capillary force is changed from the resistance force to the motive force, the residual oil is expelled from the small pores and the wall of pores, oil displacement efficiency is significantly increased.

scholarly journals Low-Abundance Dietzia Inhabiting a Water-Flooding Oil Reservoir and the Application Potential for Oil Recovery

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Peike Gao ◽  
Hongbo Wang ◽  
Guanxi Li ◽  
Ting Ma
Keyword(s):  
Oil Recovery ◽  
Water Flooding ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Recovery Potential ◽  
Oil Displacement Efficiency ◽  
Application Potential ◽  
Nutrient Injection

With the development of molecular ecology, increasing low-abundance microbial populations were detected in oil reservoirs. However, our knowledge about the oil recovery potential of these populations is lacking. In this study, the oil recovery potential of low-abundance Dietzia that accounts for less than 0.5% in microbial communities of a water-flooding oil reservoir was investigated. On the one hand, Dietzia sp. strain ZQ-4 was isolated from the water-flooding reservoir, and the oil recovery potential was evaluated from the perspective of metabolisms and oil-displacing test. On the other hand, the strain has alkane hydroxylase genes alkB and P450 CYP153 and can degrade hydrocarbons and produce surfactants. The core-flooding test indicated that displacing fluid with 2% ZQ-4 fermentation broth increased 18.82% oil displacement efficiency, and in situ fermentation of ZQ-4 increased 1.97% oil displacement efficiency. Furthermore, the responses of Dietzia in the reservoir accompanied by the nutrient stimulation process was investigated and showed that Dietzia in some oil production wells significantly increased in the initial phase of nutrient injection and sharply decreased along with the continuous nutrient injection. Overall, this study indicates that Dietzia sp. strain has application potential for enhancing oil recovery through an ex situ way, yet the ability of oil recovery in situ based on nutrient injection is limited.

scholarly journals The Research and Application of Microbial Degradation Technology on Heavy Oil Reservoir in Huabei Oilfield

2018 ◽  
Vol 38 ◽  
pp. 01054
Author(s):  
Guan Wang ◽  
Rui Wang ◽  
Yaxiu Fu ◽  
Lisha Duan ◽  
Xizhi Yuan ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
High Surface ◽  
Effective Rate ◽  
Water Flooding ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Oil Viscosity ◽  
Reservoir Conditions ◽  
Heavy Oil Reservoir

Mengulin sandstone reservoir in Huabei oilfield is low- temperature heavy oil reservoir. Recently, it is at later stage of waterflooding development. The producing degree of water flooding is poor, and it is difficult to keep yield stable. To improve oilfield development effect, according to the characteristics of reservoir geology, microbial enhanced oil recovery to improve oil displacement efficiency is researched. 2 microbial strains suitable for the reservoir conditions were screened indoor. The growth characteristics of strains, compatibility and function mechanism with crude oil were studied. Results show that the screened strains have very strong ability to utilize petroleum hydrocarbon to grow and metabolize, can achieve the purpose of reducing oil viscosity, and can also produce biological molecules with high surface activity to reduce the oil-water interfacial tension. 9 oil wells had been chosen to carry on the pilot test of microbial stimulation, of which 7 wells became effective with better experiment results. The measures effective rate is 77.8%, the increased oil is 1,093.5 tons and the valid is up to 190 days.

Improvements of Superheated Steam Stimulation in Secondary Development of Heavy Oil Reservoir

2012 ◽  
Vol 524-527 ◽  
pp. 1450-1455
Author(s):  
An Zhu Xu ◽  
Xiang Hong Wu ◽  
Zi Fei Fan ◽  
Lun Zhao ◽  
Cheng Gang Wang
Keyword(s):  
Heavy Oil ◽  
Superheated Steam ◽  
Oil Production ◽  
Saturated Steam ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Heavy Oil Reservoir ◽  
Steam Stimulation

With superheated steam, there is no direct relationship between temperature and pressure, Therefore, at a particular pressure it is possible for superheated steam to exist at a wide range of temperatures higher than that of its saturated steam. The heat transfer coefficient is 1/150-1/250 as much as that of saturated steam during heat transferring, and it takes a relatively long time to cool, during which time the steam is releasing very little energy and transmitted long distances. The mechanisms of superheated steam stimulation are mainly pointed to the performance of crude oil viscosity reduced, flow environment improved, rock wettability changed, oil displacement efficiency improved. Physical simulation shows that oil displacement efficiency by superheated steam is 6-12% higher than that of saturated steam at the same temperature, and under the condition of carrying the same heat, superheated steam enlarged the heating radius by about 10m, oil steam ratio increased by 0.7. Superheated steam stimulation was put into Kazakstan’s heavy oil reservoir after two cycles of saturated steam stimulation. The average daily oil production was 2-4 times that of saturated steam stimulation, which improved heavy oil production effectively. The secondary heavy oil thermal recovery by superheated steam stimulation applied in marginal heavy oil reservoirs achieved satisfactory effect.

Research Status and Prospect of Heavy Oil Recovery Technology

2021 ◽  
Vol 888 ◽  
pp. 111-117
Author(s):  
Yi Zhao ◽  
De Yin Zhao ◽  
Rong Qiang Zhong ◽  
Li Rong Yao ◽  
Ke Ke Li
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Development Trend ◽  
Thermal Recovery ◽  
Hot Water ◽  
Water Flooding ◽  
Oil Reservoir ◽  
Heavy Oil Recovery ◽  
Steam Flooding ◽  
Heavy Oil Reservoir

With the continuous exploitation of most reservoirs in China, the proportion of heavy oil reservoirs increases, and the development difficulty is greater than that of conventional reservoirs. In view of the important subject of how to improve the recovery factor of heavy oil reservoir, the thermal recovery technology (hot water flooding, steam flooding, steam assisted gravity drainage SAGD and steam huff and puff) and cold recovery technology (chemical flooding, electromagnetic wave physical flooding and microbial flooding) used in the development of heavy oil reservoir are summarized. The principle of action is analyzed, and the main problems restricting heavy oil recovery are analyzed The main technologies of heavy oil recovery are introduced from the aspects of cold recovery and hot recovery. Based on the study of a large number of literatures, and according to the development trend of heavy oil development, suggestions and prospects for the future development direction are put forward.

Study on Influence of Injection Method on the Effect of Oil Displacement of Nanometer Microspheres

2013 ◽  
Vol 734-737 ◽  
pp. 1272-1275
Author(s):  
Ji Hong Zhang ◽  
Zhi Ming Zhang ◽  
Xi Ling Chen ◽  
Qing Bin He ◽  
Jin Feng Li
Keyword(s):  
Oil Recovery ◽  
Experimental Result ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Profile Control ◽  
Oil Displacement Efficiency ◽  
Injection Methods ◽  
The One ◽  
Deep Profile ◽  
Enhance Oil Recovery

Nanometer microspheres injection is a new deep profile control technology. Nanometer microspheres could inflate with water, resulting in plugging step by step in reservoirs, which could improve the swept efficiency in the reservoir and enhance oil recovery. By using non-homogeneous rectangular core, oil displacement efficiency experiment was conducted for studying the influence of different injection methods on the effect of injection nanometer microspheres. The experimental result shows that, compared with development effect of single-slug injection or triple-slug injection, the one of double-slug injection is better. Nanometer microspheres can enhance oil recovery significantly in medium and low permeability reservoir.

scholarly journals The Study of Effect of Pore Structure on Oil Displacement Efficiency of Polymer Flooding

2016 ◽  
Vol 9 (1) ◽  
pp. 55-64
Author(s):  
Ma Wenguo
Keyword(s):  
Pore Structure ◽  
Oil Recovery ◽  
Water Flooding ◽  
Displacement Efficiency ◽  
Throat Radius ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Ct Technology ◽  
Micro Level ◽  
The Relationship

Characteristics of pore structure have an important influence on the development of water flooding. In order to improve the recovery rate, it is important to investigate the relationship between pore structure and oil displacement efficiency. The permeability of the artificial cores in this experiment is 189×10-3μm2, 741×10-3μm2and 21417×10-3μm2. We used the CT technology method to scan the pore structure of the three cores, and did oil displacement experiment to investigate the effect of pore structure on the oil displacement efficiency. The result shows that the pore and throat common affect oil displacement efficiency: the bigger the pore and throat radius, the better is the oil displacement efficiency; the smaller the pore and throat radius, the worse is the oil displacement efficiency. The experiment studied the influence of pore structure on oil displacement efficiency deep into microcosmic pore structure without damaging the core skeleton, thereby improving the basis of oil recovery from the micro level and the mechanism.

Experimental Research on Hot Water Flooding of Different Rhythm Heavy Oil Reservoir after the Steam Injection

2012 ◽  
Vol 550-553 ◽  
pp. 2878-2882 ◽  
Author(s):  
Ping Yuan Gai ◽  
Fang Hao Yin ◽  
Ting Ting Hao ◽  
Zhong Ping Zhang
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Physical Simulation ◽  
Steam Injection ◽  
Hot Water ◽  
Water Flooding ◽  
Oil Reservoir ◽  
Steam Flooding ◽  
Heavy Oil Reservoir ◽  
Swept Volume

Based on the issue of enhancing oil recovery of heavy oil reservoir after steam injection, this paper studied the development characteristics of hot water flooding in different rhythm (positive rhythm, anti-rhythm, complex rhythm) reservoir after steam drive by means of physical simulation. The research shows that the positive rhythm reservoir has a large swept volume with steam flooding under the influence of steam overlay and steam channeling. Anti-rhythm reservoir has a large swept volume with hot water flooding, because hot water firstly flows along the high permeability region in upper part of the reservoir, in the process of displacement, hot water migrates to the bottom of reservoir successively for its higher density.

Quantitative Evaluation of Water Flooding in a Low Resistivity Heavy Oil Reservoir with NMR and Conventional Logs

2021 ◽  
Author(s):  
Xinlei Shi ◽  
Jiansheng Zhang ◽  
Yunlong Lu ◽  
Zhilei Han ◽  
Yifan He
Keyword(s):  
Heavy Oil ◽  
Balance Equation ◽  
Material Balance ◽  
Water Flooding ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Material Balance Equation ◽  
Heavy Oil Reservoir ◽  
Mixed Water ◽  
Water Resistivity

Abstract The classification of water flooding severity is crucial for planning reservoir production and improving the recovery ratio. In this paper, we study a siliciclastic heavy oil reservoir in Bohai Bay, with resistivity reading close to, or even lower than the wet zone (3~5Ω.m). In this environment, computing original reservoir Sw using Traditional hydrocarbon saturation equation is challenging. As a result, the displacement efficiency of a water drive cannot be accurately determined. In order to properly evaluate displacement efficiency, we must estimate initial reservoir Sw (Swirr) and the modern day Sw. Sw can typically be estimated from NMR data with a proper T2 time cutoff. However, in heavy oil reservoirs, the relaxation times of oil and capillary bound water overlap, leading to an over-estimation of Sw. We propose to compensate for the heavy oil effect by adjusting the cutoff until NMR Sw matches the Sw from core Mercury Injection for Capillary Pressure (MICP). As oilfield development proceeds, water displaces some oil in the pore space. Since the injected water has higher salinity than reservoir water, formation resistivity (Rw) becomes lower. Based on the material balance theory, the variable multiple water injection material balance equation is established, and the equation set is established by combining the material balance equation with the Simandoux equation and the calculation formula of mixed water resistivity (Rwz). According to the rock electricity experiment under different salinity, the dynamic rock electricity parameters are used in the Simandoux equation, and the mixed water resistivity and modern day Sw after water flooding are solved iteratively under the original SW constraint. The displacement efficiency is calculated as the difference between Sw and modern day Sw. The proposed method was applied to 10 wells and improved the Sw accuracy by 5%-15%. The continuous solution Rw from our method matches Rw measured in the lab. The calculated displacement efficiency is compared with actual production history and the accuracy improved from 68% to 80%.

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