Selection of Effective Surfactant Composition to Improve Oil Displacement Efficiency in Carbonate Reservoirs with High Salinity Formation Water (Russian)

2019 ◽  
Author(s):  
Alexey Kornilov ◽  
Aleksey Zhirov ◽  
Andrey Petrakov ◽  
Tatiana Rogova ◽  
Yulia Kurelenkova ◽  
...  
Keyword(s):  
High Salinity ◽  
Carbonate Reservoirs ◽  
Formation Water ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Surfactant Composition ◽  
Selection Of

scholarly journals Study on the Flow Mechanism of Shale Oil with Different Injection Media

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lanlan Yao ◽  
Zhengming Yang ◽  
Haibo Li ◽  
Bo Cai ◽  
Chunming He ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Bohai Bay ◽  
Shale Oil ◽  
Formation Water ◽  
Displacement Efficiency ◽  
Pore Throat ◽  
Tight Sandstone ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Effective Development

Chinese shale oil has high recoverable resources and great development potential. However, due to the limitation of development technology, the recovery rate of shale oil is not high. In this paper, the effects of different injection media on the development of shale oil reservoirs in Dongying formation, Qikou depression, Huanghua depression, and Bohai bay basin, were studied by means of imbibition and nitrogen flooding. Combining nuclear magnetic resonance (NMR) technology with imbibition and gas displacement experiments, the mechanism of shale injected formation water, active water (surfactant), and nitrogen was reproduced. The displacement process of crude oil under different injection media and injection conditions was truly demonstrated, and the relationship between different development methods and the pore boundaries used was clarified. A theoretical basis for the effective development of shale oil was provided. At the same time, Changqing tight oil cores with similar permeability to Dagang shale oil cores were selected for comparison. The results showed that, as the imbibition time of shale samples increased, the imbibition efficiency increased. Pores with T2 < 10 ms contributed the most to imbibition efficiency, with an average contribution greater than 90%. 10 ms < T2 < 100 ms and more than 100 ms pores contributed less to imbibition efficiency. Active water can change the wettability of shale, increase its hydrophilicity, and improve the efficiency of imbibition. The imbibition recovery ratio of injected active water was 17.56% higher than that of injected formation water. Compared with tight sandstone with similar permeability, the imbibition efficiency of shale was lower. As the nitrogen displacement pressure increased, the oil displacement efficiency also increased. The higher the shale permeability was, the greater the displacement efficiency would be. T2 > 100 ms pore throat of shale contributed to the main oil displacement efficiency, with an average oil displacement efficiency contribution of 63.16%. And the relaxation interval 10 < T2 < 100 ms pore throat displacement efficiency contributed to 28.27%. T2 < 10 ms pore throat contributed the least to the oil displacement efficiency, with an average oil displacement efficiency contribution of 8.58%. Compared with tight sandstone with similar permeability, shale had lower oil displacement efficiency. The findings of this study can help for better understanding of the influence of different injection media on shale oil recovery effect.

Effect of Carbon Dioxide Dissolving in Formation Water on the Mechanism of Oil Displacement

2013 ◽  
Vol 295-298 ◽  
pp. 3148-3153
Author(s):  
Yong Tang ◽  
Yong Wang ◽  
Chang Quan Wang ◽  
Xiao Qiang Bian
Keyword(s):  
Pore Volume ◽  
Co2 Injection ◽  
Formation Water ◽  
Displacement Efficiency ◽  
Oil Saturation ◽  
Compositional Model ◽  
Oil Displacement ◽  
Phase Saturation ◽  
Oil Displacement Efficiency ◽  
Hydrocarbon Formation

In order to study the effect of CO2 dissolving in formation water on the process of CO2 injection, a thermodynamic model of CO2-hydrocarbon-formation water has been used to study the dissolving law of CO2 in formation water and oil-gas-water phase behavior considering the CO2 dissolution in formation water. Based on compositional model considering the dissolution of CO2 in formation water, a dimensional model for long core CO2 displacement is presented to simulate the oil displacement efficiency, gas/oil ratio, oil or gas saturation profile, the solubility of CO2 in in-place oil or formation water with grid distance in the process of long core displacement of CO2 injection. The results show that the solubility of CO2 in formation water increases with increasing pressure and decreases with increasing temperature, and that the solubility of CO2 in formation water is usually about 5.5 wt% at the condition of reservoir pressure and temperature. In addition, oil saturation and gas phase saturation with the consideration of CO2 dissolving in formation water lag behind those without consideration of CO2 dissolution, which results in later breakthrough time for CO2 injection. Moreover, residual oil saturation with considering CO2 dissolving in formation water is higher than that without considering CO2 dissolution at the condition of the same hydrocarbon pore volume for CO2 injection, and the ultimate recovery for the former is lower than that for the latter when pouring into 0.3 hydrocarbon pore volume of CO2.

scholarly journals A Novel Trilinear Flow Model for Capturing Dynamic Behavior of Water Flooding in Core Plug with Different Fracture Inclinations in Carbonate Reservoirs

Lithosphere ◽  
2022 ◽  
Vol 2022 (Special 4) ◽  
Author(s):  
Meng Sun ◽  
Hongxin Guo ◽  
Wenqi Zhao ◽  
Peng Wang ◽  
Lun Zhao ◽  
...  
Keyword(s):  
Flow Model ◽  
Carbonate Reservoirs ◽  
Water Flooding ◽  
Displacement Efficiency ◽  
Fracture Permeability ◽  
Linear Flow ◽  
Oil Displacement ◽  
The Matrix ◽  
Oil Displacement Efficiency ◽  
Dip Angle

Abstract The purpose of this study is to introduce a new three-linear flow model for capturing the dynamic behavior of water flooding with different fracture occurrences in carbonate reservoirs. Low-angle and high-angle fractures with different occurrences are usually developed in carbonate reservoirs. It is difficult to simulate the water injection development process and the law of water flooding is unclear, due to the large variation of the fracture dip. Based on the characteristics of water flooding displacement streamlines in fractured cores with different occurrences, the matrix is discretized into a number of one-dimensional linear subregions, and the channeling effect between each subregion is considered in this paper. The fractures are divided into the same number of fracture cells along with the matrix subregion, and the conduction effect between the fracture cells is considered. The fractured core injection-production system is divided into three areas of linear flow: The injected fluid flows horizontally and linearly from the matrix area at the inlet end of the core to the fracture and then linearly diverts from the fracture area. Finally, the matrix area at the outlet end of the core also presents a horizontal linear flow pattern. Thus, a trilinear flow model for water flooding oil in fractured cores with different occurrences is established. The modified BL equation is used to construct the matrix water-flooding analytical solution, and the fracture system establishes a finite-volume numerical solution, forming a high-efficiency semianalytical solution method for water-flooding BL-CVF. Compared with traditional numerical simulation methods, the accuracy is over 86%, the model is easy to construct, and the calculation efficiency is high. In addition, it can flexibly portray cracks at any dip angle, calculate various indicators of water flooding, and simulate the pressure field and saturation field, with great application effect. The research results show that the greater the fracture dip angle, the higher the oil displacement efficiency. When the fracture dip angle is above 45°, the fracture occurrence has almost no effect on the oil displacement efficiency. The water breakthrough time of through fractures is earlier than that of nonthrough fractures, and the oil displacement efficiency and injection pressure are more significantly affected by the fracture permeability. With the increase of fracture permeability, the oil displacement efficiency and the injection pressure of perforated fractured cores dropped drastically. The findings of this study can help for better understanding of the water drive law and optimizing its parameters in cores with different fracture occurrences. The three-linear flow model has strong adaptability and can accurately solve low-permeability reservoirs and high-angle fractures, but there are some errors for high-permeability reservoirs with long fractures.

scholarly journals Study on oil displacement efficiency of offshore sandstone reservoir with big bottom water

2021 ◽  
Author(s):  
Jie Tan ◽  
Ying-xian Liu ◽  
Yan-lai Li ◽  
Chun-yan Liu ◽  
Song-ru Mou
Keyword(s):  
Bottom Water ◽  
High Water ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Sandstone Reservoir ◽  
Sandstone Reservoirs ◽  
High Water Cut Stage ◽  
High Water Cut ◽  
Water Cut

AbstractX oilfield is a typical sandstone reservoir with big bottom water in the Bohai Sea. The viscosity of crude oil ranges from 30 to 425 cp. Single sand development with the horizontal well is adopted. At present, the water content is as high as 96%. The water cut of the production well is stable for a long time in the high water cut period. The recoverable reserves calculated by conventional methods have gradually increased, and even the partial recovery has exceeded the predicted recovery rate. This study carried out an oil displacement efficiency experiment under big water drive multiple to accurately understand an extensive bottom water reservoir's production law in an ultra-high water cut stage. It comprehensively used the scanning electron microscope date, casting thin section, oil displacement experiment, and production performance to analyze the change law of physical properties and relative permeability curve from the aspects of reservoir clay minerals, median particle size, pore distribution, and pore throat characteristics. Therefore, the development law of horizontal production wells in sandstone reservoirs with big bottom water is understood. It evaluates the ultimate recovery of sandstone reservoirs with big bottom water. It provides a fundamental theoretical basis and guidance for dynamic prediction and delicate potential tapping of sandstone reservoirs with big bottom water at a high water cut stage.

Experimental Study on the Displacement Performance of Heat-Resistant Polymer

2014 ◽  
Vol 675-677 ◽  
pp. 1495-1499 ◽  
Author(s):  
Tao Ping Chen ◽  
Biao Qiu
Keyword(s):  
Polymer Flooding ◽  
Displacement Efficiency ◽  
Oil Viscosity ◽  
Permeability Ratio ◽  
Ratio Increase ◽  
Displacement Effect ◽  
Oil Displacement ◽  
Heat Resistant ◽  
Homogeneous Core ◽  
Oil Displacement Efficiency

The displacement performance of heat-resistant polymer is evaluated with the artificial cores and natural cores under 95°C. The best concentration of BH heat-resistant polymer is 1500 mg/L, and the best slug is 0.6 PV on the condition of the average permeability is 600×10-3μm2 of the homogeneous core and the oil viscosity is 2.3mPa • s. Under the best concentration and the PV size, BH heat-resistant polymer solution has better displacement effect for the artificial double core whose permeability ratio is less than 4. When permeability ratio exceed 4, the displacement affect no longer increase. When the mobility ratio increase from 0.05 to 0.2, for the artificial cores, the recovery of polymer flooding reduce by 3.17%, and for the natural cores, the recovery of polymer flooding reduce by 2.26%. The recovery of BH polymer that is aged for 90 days after vacuumed is 32.29%. Comparing with the fresh BH polymer, it is lower by 6.56%. That is to say that the aged BH polymer still has good oil displacement efficiency.

Research and Application of Multi-Slug and Equi-Fluidity Oil Displacement Mechanism

2015 ◽  
Vol 733 ◽  
pp. 43-46
Author(s):  
Jiang Min Zhao ◽  
Tian Ge Li
Keyword(s):  
Pressure Gradient ◽  
Flow Rate ◽  
Oil Recovery ◽  
Recovery Rate ◽  
Actual Situation ◽  
Displacement Efficiency ◽  
Displacement Method ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Swept Volume

In this paper, several aspects of the improvement of the oil recovery were analyzed theoretically based on the mechanism that equi-fluidity enhances the pressure gradient. These aspects include the increase of the flow rate and the recovery rate, of the swept volume, and of the oil displacement efficiency. Also, based on the actual situation, the author designed the oil displacement method with gathered energy equi-fluidity, realizing the expectation of enhancing oil recovery with multi-slug and equi-fluidity oil displacement method.

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.

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