Article
Thermodynamics
Hao Chen, Xiliang Liu, Chao Zhang, Xianhong Tan, Ran Yang, Shenglai Yang, Jin Yang
Summary: This study focuses on the impact of supercritical CO2 injection on oil recovery in reservoirs, showing that the decrease in gas relative permeability leads to a similar ultimate oil recovery between near-miscible flooding and miscible flooding. A new threshold pressure gradient is proposed as an indicator of reservoir fluids' seepage capacity, emphasizing the importance of CO2-SAG flooding in enhancing oil recovery.
Article
Engineering, Chemical
Lijun Zhang, Tianwei Sun, Xiaobing Han, Jianchao Shi, Jiusong Zhang, Huiting Tang, Haiyang Yu
Summary: This study investigates the CO2 injection development in tight-oil reservoirs in the Ordos Basin. The results demonstrate that advanced CO2 injection can effectively enhance oil recovery and achieve CO2 sequestration. Well pattern adjustment significantly improves CO2 storage and reduces gas-oil ratio in production wells. Furthermore, well pattern adjustment supplements formation energy, extends the production lives of wells, and increases sweep efficiency and oil recovery.
Article
Engineering, Chemical
Linqiang Zhang, Tongzhou Bai, Qibin Zhao, Xinghua Zhang, Hanlie Cheng, Zhao Li
Summary: With the popularization of natural gas and the requirements for environmental protection, the development and utilization of natural gas is particularly important. Injecting carbon dioxide into the formation can improve the recovery rate of natural gas and achieve carbon neutrality. Injecting greenhouse gases into gas reservoirs for storage and improving recovery has also become a hot research issue.
Article
Multidisciplinary Sciences
Xuecheng Zheng, Zilong Mei, Xuefeng Zhou, Siqi Chen, Nanjun Lai
Summary: The development of fractures in tight reservoirs and the difference in viscosity between CO2 and crude oil often lead to channeling and low sweep efficiency during CO2 flooding. The use of CO2-responsive polymer microspheres shows potential in controlling gas channeling and improving oil recovery in tight reservoirs. By preparing a CO2-responsive polymer microsphere (CRM) through seed lotion polymerization, CRM's swelling property and shear resistance were studied. The results showed that CRM could be protonated by CO2 and its swelling ratio and particle size retention rate were measured. This research provides feasible materials and theoretical support for the development and application of tight reservoirs.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Geochemistry & Geophysics
Zhanwu Gao, Xuewei Liu, Yuanli Zhang, Xinli Zhao
Summary: This research studied the interfracture injection and production law of different displacing medium in Changqing oilfield. The results showed that natural gas drive reduces Jamin resistance and promotes rapid oil production, but may lead to gas breakthrough and decreased gas utilization ratio. Surfactant-oil displacement was not very effective, but had higher oil displacement efficiency compared to natural gas injection.
Article
Chemistry, Physical
Wan-fen Pu, Dai-jun Du, Huan-cai Fan, Bo-wen Chen, Cheng-Dong Yuan, Mikhail A. Varfolomeev
Summary: By synthesizing novel CO2-responsive preformed gel particles with interpenetrating networks (IPN-ASSAP), the breakthrough of CO2 can be effectively mitigated and plugging efficiency can be improved. Experimental results indicated that IPN-PAASP has great potential for fracture plugging during CO2 flooding.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Engineering, Environmental
Yong Tang, Shilai Hu, Youwei He, Yong Wang, Xiaojin Wan, Shuheng Cui, Keji Long
Summary: The study demonstrates that the interaction between CO2-brine-rock occurs in both gas zone and water zone, leading to more severe reservoir damage in the gas zone than in the water zone. However, in water zones with good-quality reservoirs, this interaction can improve reservoir porosity and permeability.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Energy & Fuels
Songyan Li, Lu Sun, Lei Wang, Zhaomin Li, Kaiqiang Zhang
Summary: This study investigates the efficacy of hybrid CO2-N-2 gases as gas solvents for enhancing tight oil recovery through laboratory tests, finding that the optimal ratio of CO2-N-2 is 1:2 with a best oil recovery of 39.0%. It is observed that the first three HnP cycles typically have higher oil recovery, with subsequent cycles being less beneficial. The NMR-assisted coreflood tests reveal uneven residual oil distributions and the varying effectiveness of CO2 and N-2 HnP in different pore scales, where N-2 HnP shows better oil extraction ability in small pores.
Article
Energy & Fuels
Ogochukwu Ozotta, Mehdi Ostadhassan, Kouqi Liu, Bo Liu, Oladoyin Kolawole, Fahimeh Hadavimoghaddam
Summary: CO2 sequestration and CO2 enhanced oil recovery are two major processes that expose rocks to CO2, affecting their mechanical and chemical properties. Storage of CO2 in tight formations is crucial for energy transition and climate change mitigation, but may also lead to potential leakage or induced fractures.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Xiangling Li, Kang Xiao, Ruifeng Wang, Xianbing Li
Summary: Gas injection is an effective method for enhancing oil recovery in low-permeability and tight reservoirs, with the presence of fractures affecting its performance. This study conducted microfluidic experiments using micromodels simulating fractured reservoirs and evaluated the oil displacement effects of different gas injection methods. The simultaneous injection of gas and water showed the highest enhanced oil recovery effect among the tested methods.
Article
Environmental Sciences
Qiang Li, Yanling Wang, Fuling Wang, Xu Ning, Zhang Chuanbao, Jinyan Zhang, Chenglin Zhang
Summary: This study explores the filtration characteristics of supercritical CO2 with branched siloxane as a thickener and filtration-reducing agent in tight shale reservoirs. The results show that thickener concentration is the key factor affecting the filtration coefficient, while injection speed has the least impact on filtration.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Energy & Fuels
Sofiane Haythem Achour, Ryosuke Okuno
Summary: This paper presents a mechanistic simulation study of one-dimensional multicomponent diffusion in a tight reservoir, considering non-ideal interactions, fugacity coefficients, and volume change. The study shows that characterizing the non-ideal behavior of reservoir fluids is crucial for improving early-time flux.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Weiyu Tang, James J. Sheng
Summary: This study examines the effects of different gas injection modes on oil recovery in tight formations with varying permeabilities through experiments and numerical simulations. Results show that gas flooding is more efficient at higher permeabilities, while huff-n-puff injection is superior at lower permeabilities.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Environmental Sciences
Huaijing Wang, Jiaqiang Wei, Haoyin Xu, Pengyu Zhang
Summary: This paper evaluates the effects of gravity differentiation, pressure holding amplitude, and fracturing modification on the displacement process of tight sandstone gas reservoirs through indoor long core displacement evaluation experiments. The results show that gravity differentiation increases the initial production rate but decreases the final recovery rate; the lower the pressure holding value, the greater the final recovery rate. Fracturing technology can solve the reservoir lock-up caused by low pressure holding values.
FRESENIUS ENVIRONMENTAL BULLETIN
(2022)
Article
Energy & Fuels
Fahad Iqbal Syed, Temoor Muther, Vuong Pham Van, Amirmasoud Kalantari Dahaghi, Shahin Negahban
Summary: This study focuses on improving oil recovery from tight oil reservoirs and storing CO2 to reduce carbon emissions. By building a numerical simulation model and discussing CO2 trapping and diffusivity mechanisms at the nanopore scale, the study finds that CO2 injection significantly enhances oil recovery. Reservoirs with lighter in-situ fluid composition and higher pressure show better oil recovery performance. Increasing the number of injection cycles and injection volume also improves oil recovery and helps trap more CO2. The findings provide insights for designing EOR operations in tight oil reservoirs to achieve multiple goals simultaneously.
Article
Engineering, Petroleum
Bing Wei, Qingtao Tian, Shengen Chen, Xingguang Xu, Dianlin Wang, Jun Lu
Summary: This study investigated the generation, propagation, and sweep of nanocellulose-strengthened CO2 foam in a visual 2D heterogeneous fracture network model. NCF-st-CO2 foam demonstrated superior performance in reducing gas mobility and maintained stable foam generation with increasing total superficial velocity.
Article
Energy & Fuels
Meirong Tang, Chengwang Wang, Xian'an Deng, Haifeng Yang, Jun Lu, Haiyang Yu
Summary: This paper investigates the application of nanospheres for water plugging before fracturing in low-permeability reservoirs. The plugging performance of nanospheres in different zones is evaluated, and the results show that nanospheres have a good plugging effect in the bottom water layer, oil-water transition zones, and fracturing zones.
ADVANCES IN GEO-ENERGY RESEARCH
(2022)
Article
Energy & Fuels
Haiyang Yu, Jiabang Song, Zhewei Chen, Yu Zhang, Yang Wang, Weipeng Yang, Jun Lu
Summary: Due to the problem of low formation pressure in the shale oil reservoirs of the Ordos Basin, traditional fluid injection methods have proven to be ineffective. This paper proposes a new injection-production pattern called Allied In-situ Injection and Production (AIIP), which divides one horizontal well into 3 segments to improve fluid injectivity and sweep efficiency. The research shows that AIIP can better maintain formation pressure and achieve higher oil recovery compared to huff-n-puff and vertical injection methods.
Article
Energy & Fuels
Xing Huang, Yu Zhang, Mengqing He, Xiang Li, Weipeng Yang, Jun Lu
Summary: This study investigates the characteristics of asphaltene precipitation under different CO2 flooding conditions and evaluates the damage degree and impact on oil displacement efficiency in different types of reservoirs. The results show that asphaltene precipitation has high damage on permeability but little effect on porosity. Additionally, the use of surfactants can reduce the wettability reversal caused by asphaltene precipitation.
Article
Water Resources
Weipeng Yang, Guoyu Chu, Yujing Du, Ke Xu, Erdong Yao, Tianbo Liang, Bing Wei, Haiyang Yu, Jian Hou, Jun Lu
Summary: Surfactant flooding is widely used in subsurface applications where high displacement efficiency is needed. The partitioning of surfactants in each phase is controlled by external factors, such as salinity. The spatially non-homogeneous surfactant concentrations can significantly affect the displacement patterns in porous media, but the influence of spatially non-homogeneous contact angle and IFT on displacement has not been sufficiently explored.
ADVANCES IN WATER RESOURCES
(2022)
Article
Thermodynamics
Bing Wei, Jiang Liu, Xiang Zhang, Dianlin Wang, Junyu You, Jun Lu, Jinyu Tang
Summary: The objective of this work was to study the mass exchange dynamics between the tight rock matrix and fractures induced by natural gas soaking during Huff-n-Puff. The equilibrium interfacial tension between natural gas and oil decreased with an increase in the gas fraction and equilibrium pressure. The mass exchange between matrix and fracture was driven by gas diffusion, oil swelling, and concentration gradient-driven flow, resulting in increased oil recovery.
Article
Energy & Fuels
Songchao Qi, Haiyang Yu, Zhiming Chen, Honglei Liu, Yang Wang, Weipeng Yang, Jun Lu
Summary: This study proposes a countercurrent imbibition extension model for porous medium with micro-/nanopores, and verifies its reliability through experimental data. The countercurrent imbibition process is divided into three stages, and key parameters are obtained to determine the optimal soaking time for higher oil recovery.
Article
Environmental Sciences
Yanyu Lu, Yao Huang, Qianlai Zhuang, Wei Sun, Shutao Chen, Jun Lu
Summary: China's terrestrial ecosystems have played a significant role in the carbon cycle during the 20th century. The rising temperature and CO2 concentration have enhanced the carbon sink strength in China's terrestrial ecosystems. Although climate change has contributed to the increase in carbon sinks, the positive effect has diminished in recent decades.
CARBON BALANCE AND MANAGEMENT
(2022)
Article
Engineering, Chemical
Runxue Mao, Bing Wei, Qingtao Tian, Lele Wang, Jinyu Tang, Jun Lu, Xingguang Xu
Summary: The mechanical properties of particle gel were significantly improved due to the interpenetration of high-modulus nanocellulose into polyacrylamide. Five transport patterns in fractures were identified based on the particle/aperture ratio. A numerical model was established to correlate the stable pressure drop of nanocellulose-regulated particle gel with four critical operating parameters. The injection of particle gel greatly improved the conformance of fractured cores and resulted in additional oil recoveries.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Energy & Fuels
Songchao Qi, Haiyang Yu, Feifan Xie, Mengpo Hu, Jun Lu, Yang Wang
Summary: This paper investigates the effective distance and saturation profiles of CO2 in tight cores and quantitatively evaluates CO2-enhanced oil recovery (EOR) storage. The results show that the increase of CO2 effective distance slows down with time, and the decrease of permeability significantly reduces the effective distance. The experiments reveal that the CO2 storage ratio can reach up to 72.31% under different depressurization conditions. The collaboration optimization of maximizing oil production and CO2 storage ratio is observed. The oil composition has little influence, while permeability plays a significant role in the effective distance and CO2-EOR storage.
Article
Energy & Fuels
Xing Huang, Zhen Tian, Xiongdi Zuo, Xiang Li, Weipeng Yang, Jun Lu
Summary: This study establishes classification and evaluation standards for shale oil reservoirs and finds that DME-assisted CO2 flooding has higher recovery compared to pure CO2 flooding. Additionally, higher injection pressure and injection volume lead to higher recovery.
Article
Energy & Fuels
Teng Li, Hui Gao, Jun Ni, Chen Wang, Zhilin Cheng, Junjie Xue, Kaiqing Luo
Summary: CO2 injection is an effective method for improving oil recovery in tight sandstone reservoirs. This study examined the oil producing degree in different sized pores of tight sandstone cores collected from the Ordos Basin. The results showed that continuous CO2 flooding achieved an oil producing degree of 73.29%, while CO2 huff and puff had a higher degree of 82.03%. The study also found that certain types of pores had higher oil producing degrees and smaller differences under both injection modes. The size of the pores had a significant effect on oil producing degree, with smaller pores showing higher differences under CO2 huff and puff.
Article
Energy & Fuels
Xing Huang, Xingyu Wang, Mengqing He, Yu Zhang, Zezhong Su, Xiang Li, Weipeng Yang, Jun Lu
Summary: CO2 huff-n-puff can store CO2 and enhance tight oil recovery. Asphaltene precipitation caused by CO2-oil interaction damages tight oil reservoirs. This study establishes a microscopic classification standard and quantitatively evaluates the influence of asphaltenes on pore structure and oil recovery. Results show that asphaltene precipitation is positively correlated with huff-n-puff rounds and injection pressure. The research provides novel insights into reservoir characterization and optimization of field development parameters.
Article
Energy & Fuels
Junjie Xue, Hui Gao, Xiaoyong Wen, Meiqiang Wang, Zhilin Cheng, Chen Wang, Teng Li, Bo Han, Kaiqing Luo, Nan Zhang
Summary: This study examines the impact of CO2 huff-n-puff after CO2 flooding on recovery efficiency in tight sandstone reservoirs. The experimental approach involved using three representative cores with different permeability levels to simulate different reservoir types. By employing a physical simulation flow system integrated with nuclear magnetic resonance technology, the researchers analyzed oil production characteristics during flooding and huff-n-puff processes. The findings provide valuable insights into microscopic production characteristics and oil recovery influenced by huff-n-puff in tight sandstone reservoirs subsequent to CO2 flooding.
Article
Energy & Fuels
Hui Gao, Chen Wang, Zhilin Cheng, Teng Li, Liangbin Dou, Kai Zhao, Junjie Xue, Kaiqing Luo
Summary: The pressure pulse technique is a potential method to enhance oil recovery from tight oil reservoirs. By investigating the variations in the pore structure of tight sandstone samples from the Triassic Yanchang Formation in the Ordos Basin, it was found that a series of four pulses at specific pressures and pulse times could significantly enhance the oil recovery. Employing the pressure pulse method can markedly improve the imbibition oil recovery, and the simultaneous pulse pressure with imbibition leads to a higher oil recovery than the approach that adopts the pulse pressure after imbibition experiments.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
