scholarly journals Study on Fluid Behaviors of Foam-Assisted Nitrogen Flooding on a Three-Dimensional Visualized Fracture–Vuggy Model

2021 ◽  
Vol 11 (23) ◽  
pp. 11082
Author(s):  
Ming Qu ◽  
Tuo Liang ◽  
Jirui Hou
Keyword(s):  
Three Dimensional ◽  
Northwest China ◽  
Carbonate Reservoir ◽  
Water Flooding ◽  
Residual Oil ◽  
Sweep Efficiency ◽  
Nitrogen Gas ◽  
Gas Flooding ◽  
Oil Water ◽  
Gas Channeling

Tahe Oilfield, located in northwest China, is an unconventional fracture–vuggy carbonate reservoir. The foam-assisted nitrogen gas flooding technology has been proven to be a potential EOR technology. However, the flow behaviors of foam-assisted nitrogen gas in fracture–vuggy structures are not clear due to the complex fracture–vuggy structures and their strong heterogeneity. In this work, a three-dimensional visualized fracture–vuggy model is designed and fabricated to investigate the fluids behaviors of foam-assisted N2 flooding and classify the residual oil types after foam-assisted N2 flooding. Experimental results reveal that foam slug can enlarge the sweep efficiency, suppress the formation of nitrogen gas channeling, and detach the oil film. Additionally, the evolution processes of the gas–oil and oil–water interfaces are investigated and analyzed. Moreover, the residual oil types after foam-assisted N2 flooding and nitrogen gas flooding, respectively, are classified and summarized. Compared to nitrogen gas flooding after water flooding, 12.36% more oil can be recovered through foam-assisted N2 flooding. This work further studies the fluid flow behaviors of foam-assisted N2 in the three-dimensional visualized fracture–vuggy carbonate model and also confirms the previous achievements.

Field Pilot Test of Micro-Dispersed Gel Foam in Fractured-Vuggy Carbonate Reservoirs

2021 ◽  
Author(s):  
Yuchen Wen ◽  
Jirui Hou ◽  
Ming Qu ◽  
Weipeng Wu ◽  
Tuo Liang ◽  
...  
Keyword(s):  
Gas Injection ◽  
Carbonate Reservoir ◽  
Production Performance ◽  
Injection Well ◽  
Pilot Test ◽  
Nitrogen Gas ◽  
Before And After ◽  
Production Wells ◽  
Gas Flooding ◽  
Gas Channeling

Abstract This paper summarizes the change rule of production performance and the EOR efficiency from the micro-dispersed gel foam injection in the fractured-vuggy carbonate reservoir of Tahe Oilfield. The TK722CH2 well group injected gas from August 2014 to September 2018. During the gas injection stage, the effect of periodic gas injection decreased obviously, the effective direction of gas injection was single and the risk of gas channeling increased greatly. The field pilot test f micro-dispersed gel foam was carried out on September 20, 2018. The fluid is injected into well group in three slugs: micro-dispersed gel foam, normal foam and nitrogen gas. As a part of the foam pilot test monitoring, a gas tracer study was performed before and after the injection of gel foam in the reservoir. After the pilot test was carried out in the TK722CH2 well group, the subsequent injection gas swept new fractures and vugs, and a new dynamic connectivity has been established. The connectivity of well group changed from 1 injection well connects with 1 production well to 1 injection well connects with 4 production wells. Through the field pilot test of micro-dispersed gel foam, this paper verifies the effect of improve gas flooding and increase sweep volume of micro-dispersed gel foam. By analyzing the results of the field pilot test, the relevant technical mechanism of micro-dispersed gel foam in fractured-vuggy reservoir is revealed. As a result, the field pilot test in this paper provides theoretical basis and technical support for the efficient development of fractured-vuggy carbonate reservoir.

3-D Visual Experiments on Fluid Flow Behavior of Water Flooding and Gas Flooding in Fractured-Vuggy Carbonate Reservoir

2017 ◽  
Author(s):  
Ming Qu ◽  
Jirui Hou ◽  
Fenglan Zhao ◽  
Zhaojie Song ◽  
Shixi Ma ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Flow Behavior ◽  
Carbonate Reservoir ◽  
Water Flooding ◽  
Gas Flooding

Research on Residual Oil Distribution Regular with the Application of Facies Controlled Modeling and Reservoir Numerical Simulation

2012 ◽  
Vol 616-618 ◽  
pp. 126-132 ◽  
Author(s):  
Hua Bin Wei ◽  
Shang Ming Shi ◽  
Pan Zhao ◽  
Dong Kai Huo ◽  
Wan Zhen Zhu
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Simulation Method ◽  
Structural Features ◽  
Development Stage ◽  
Water Flooding ◽  
Residual Oil ◽  
Distribution Law ◽  
North West ◽  
Oil Distribution

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.

scholarly journals A Pore-Scale Investigation of Residual Oil Distributions and Enhanced Oil Recovery Methods

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3732 ◽  
Author(s):  
Yaohao Guo ◽  
Lei Zhang ◽  
Guangpu Zhu ◽  
Jun Yao ◽  
Hai Sun ◽  
...  
Keyword(s):  
Porous Media ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Scale Model ◽  
Pore Scale ◽  
Residual Oil ◽  
Sweep Efficiency ◽  
Significant Difference

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.

scholarly journals Experimental Study on Medium Viscosity Oil Displacement Using Viscoelastic Polymer

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Huiying Zhong ◽  
Qiuyuan Zang ◽  
Hongjun Yin ◽  
Huifen Xia
Keyword(s):  
Oil Recovery ◽  
Polymer Flooding ◽  
Water Soluble ◽  
Water Flooding ◽  
Bohai Bay ◽  
Residual Oil ◽  
Displacement Efficiency ◽  
Sweep Efficiency ◽  
Oil Displacement ◽  
Medium Viscosity

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.

scholarly journals Microscopic Residual Oil Distribution Characteristics and Quantitative Characterization of Producing Degree Based on Core Fluorescence Analysis Technology

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Huifen Xia ◽  
Lihui Wang ◽  
Peihui Han ◽  
Ruibo Cao ◽  
Siqi Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Fluorescence Analysis ◽  
Pore Surface ◽  
Distribution Characteristics ◽  
Residual Oil ◽  
Quantitative Characterization ◽  
Adsorption State ◽  
The Core ◽  
Oil Water

In this study, to address the insufficiency of research on the distribution characteristics and quantitative characterization of oil, water, and rock in a reservoir, laser confocal and core fluorescence analysis techniques are combined with core flooding experiments to investigate oil–water distribution characteristics in the core and the microscopic origin of residual oil. The results obtained show that the three-dimensional (3D) distribution characteristics of oil, water, and rock can be depicted using a laser confocal technique. Free and bound states are dominated by water flooding, and their total proportion is 93.65%, while the semibound state only accounts for 6.35% of the total. Polymer flooding has clear effects such as production of cluster-like residual oil, interparticle adsorption state residual oil, pore surface oil film, and corner residual oil. After alkali-surfactant-polymer (ASP) flooding, the residual oil produced at the lowest degree corresponds to particle adsorption oil, pore surface oil films, and interparticle adsorption state residual oil. The emulsion transition process in porous media, i.e., Winsor I→Winsor III→Winsor II, is studied. Moreover, the fluorescence analysis technology is used to clarify the causes for residual oil production, namely, pore structure, crude oil viscosity, the Jia Min effect, particle migration, and adsorption capacity. The combination of laser confocal and fluorescence analysis technology can help realize the three-dimensional reconstruction of the fluid in the core, and it can quantitatively characterize the microscopic residual oil. According to the analysis results, it can also guide the formulation and adjustment of oilfield development plans.

Analysis of Nitrogen Gas Flooding Development Effect on Water-Flooding Reservoirs

2014 ◽  
Vol 1010-1012 ◽  
pp. 1684-1688
Author(s):  
Zi Ji Wang ◽  
Yue Dong Yao ◽  
Jian Uan Wang ◽  
Xu Zhou ◽  
Chang Fa Qiao ◽  
...  
Keyword(s):  
Water Flooding ◽  
Nitrogen Gas ◽  
Development Method ◽  
Optimal Scheme ◽  
Scheme Design ◽  
Nitrogen Injection ◽  
Minimum Miscibility Pressure ◽  
Development Scheme ◽  
Water Alternating Gas ◽  
Gas Flooding

This study evaluated the potential for application of nitrogen injection to Dujiatai which is a water-flooding reservoir developing for decades. ECLIPSE PVTi module of simulation was employed to determine N2-oil MMP (Minimum miscibility pressure) which is as a criterion for screening. Then, through nitrogen flooding development scheme design and index prediction of a typical well group, we get the optimal water alternating gas (WAG) scheme. The optimal scheme can obvious increase the reservoir recovery for the next decade, which can be a useful development method for similar water-flooding reservoirs.

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