scholarly journals Formulation Development of High Strength Gel System and Evaluation on Profile Control Performance for High Salinity and Low Permeability Fractured Reservoir

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Chengli Zhang ◽  
Guodong Qu ◽  
Guoliang Song
Keyword(s):  
High Salinity ◽  
Crosslinking Agent ◽  
High Strength ◽  
Gel Strength ◽  
Water Flooding ◽  
Low Permeability ◽  
Control Performance ◽  
Formulation Development ◽  
Profile Control ◽  
Gel System

For the large pores and cracks of reservoirs with low temperatures, high salinity, and low permeability, a new type of high strength gel ABP system is developed in this paper. The defects of conventional gels such as weak gel strength, no gelling, and easy dehydration are overcome under the conditions of low temperature and high salinity. The temperature and salt resistance, plugging characteristics, and EOR of the gel system are studied. Under the condition of 32°C and 29500 mg/L salinity, the ABP system formulation is for 0.3% crosslinking agent A + 0.09% coagulant B + 3500 mg/L polymer solution P. The results show that when the temperature was increased, the delayed crosslinking time of the system was shortened and the gel strength was increased. The good plugging characteristics of the ABP system were reached, and the plugging rate was greater than 99% in cores with different permeability. A good profile control performance was achieved, and the recovery rate was improved by 19.27% on the basis of water flooding. In the practical application of the gel system, the salinity of formation water and the permeability of fractures are necessary to determine the appropriate formulation.

scholarly journals Enhanced oil recovery ability of branched preformed particle gel in heterogeneous reservoirs

2018 ◽  
Vol 73 ◽  
pp. 65 ◽  
Author(s):  
Long Yu ◽  
Qian Sang ◽  
Mingzhe Dong
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Water Flooding ◽  
Low Permeability ◽  
High Permeability ◽  
Sweep Efficiency ◽  
Reservoir Heterogeneity ◽  
Heterogeneous Reservoirs ◽  
Preformed Particle Gel ◽  
Profile Control

Reservoir heterogeneity is the main cause of high water production and low oil recovery in oilfields. Extreme heterogeneity results in a serious fingering phenomenon of the displacing fluid in high permeability channels. To enhance total oil recovery, the selective plugging of high permeability zones and the resulting improvement of sweep efficiency of the displacing fluids in low permeability areas are important. Recently, a Branched Preformed Particle Gel (B-PPG) was developed to improve reservoir heterogeneity and enhance oil recovery. In this work, conformance control performance and Enhanced Oil Recovery (EOR) ability of B-PPG in heterogeneous reservoirs were systematically investigated, using heterogeneous dual sandpack flooding experiments. The results show that B-PPG can effectively plug the high permeability sandpacks and cause displacing fluid to divert to the low permeability sandpacks. The water injection profile could be significantly improved by B-PPG treatment. B-PPG exhibits good performance in profile control when the high/low permeability ratio of the heterogeneous dual sandpacks is less than 7 and the injected B-PPG slug size is between 0.25 and 1.0 PV. The oil recovery increment enhanced by B-PPG after initial water flooding increases with the increase in temperature, sandpack heterogeneity and injected B-PPG slug size, and it decreases slightly with the increase of simulated formation brine salinity. Choosing an appropriate B-PPG concentration is important for B-PPG treatments in oilfield applications. B-PPG is an efficient flow diversion agent, it can significantly increase sweep efficiency of displacing fluid in low permeability areas, which is beneficial to enhanced oil recovery in heterogeneous reservoirs.

Injection Method of SJT-B Collosol in the Low Permeability Reservoir

2014 ◽  
Vol 694 ◽  
pp. 340-345
Author(s):  
Ke Liang Wang ◽  
Jin Yu Li ◽  
Lei Lei Zhang ◽  
Xue Li ◽  
Guo Qiang Fu ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Normal Pressure ◽  
Water Flooding ◽  
Low Permeability ◽  
Injection Method ◽  
Low Permeability Reservoir ◽  
Medium Permeability ◽  
Profile Control ◽  
Long Time ◽  
Core Permeability

Profile control and flooding technique is an effective way to enhance the oil recovery of low permeability reservoir.Analyzing the relation between oil and water interface and determining injection volume under different concentration is the key to success in profile controlling and flooding in low permeability reservoir .The research is about SJT-B collosol of physicochemical property under normal pressure and temperature.We also carry on the study on measuring SJT-B collosol interfacial tension for a long time under different concentration.Besides, we conduct the plugging degree experiment by injecting SJT-B collosol with the concentration of 0.8% in different permeability core.The lower the core permeability, the higher the plugging degree. By optimizing the injection pattern we conduct the three-tube parallel profile control and flooding experiment in the low permeability heterogeneous core.It indicates that SJT-B collosol mainly access to high permeability layer and have an effective plugging effect .The absorbed liquid rate of medium permeability layer is increased apparently ,while low permeability layer is increased slightly.The SJT-B collosol of injection method has efficient effect on enhancing the oil recovery of low permeability reservoir in late water flooding.

Experimental Study on High Temperature-Resistant Gel for Profile Control

2015 ◽  
Vol 733 ◽  
pp. 165-168 ◽  
Author(s):  
Shao Bin Hu ◽  
Peng Wang ◽  
Chang Liang Chen ◽  
Shao Ke Liu ◽  
Zhe Wang
Keyword(s):  
High Temperature ◽  
Oil Recovery ◽  
Volume Fraction ◽  
Crosslinking Agent ◽  
Reservoir Water ◽  
Good Thermal Stability ◽  
Heat Stabilizer ◽  
Profile Control ◽  
Weak Gel ◽  
Gel System

In order to control water and increase oil recovery in reservoir of high temperature (120°C), experiments were carried out to study the impacts of dosage of HPAM, crosslinking agent, delayed crosslinking agent and heat stabilizer on the properties of gel system, and a high temperature-resistant movable weak gel profile control system was presented, whose formula is 2.0g/L HPAM + 0.2% (volume fraction) crosslinking agent + 0.1g/L delayed crosslinking agent + 0.1g/L heat stabilizer. This gel system has good thermal stability at 120°C. It has good flow properties before gelation, and can effectively enter larger pores. After gelation, its viscosity increases so significantly that it can be stranded and the larger pores can be plugged. The plugging rate can be over 93%. Thus, subsequent fluid injection can be redirected into the low-permeability layers, effectively improving the reservoir water absorption profile and oil recovery.

Subcritical Crack Growth and Long-Term Strength in Rock and High-Strength and Ultra Low-Permeability Concrete

2009 ◽  
Vol 58 (6) ◽  
pp. 525-532 ◽  
Author(s):  
Yoshitaka NARA ◽  
Masafumi TAKADA ◽  
Daisuke MORI ◽  
Hitoshi OWADA ◽  
Tetsuro YONEDA ◽  
...  
Keyword(s):  
Crack Growth ◽  
Subcritical Crack Growth ◽  
High Strength ◽  
Low Permeability ◽  
Term Strength

Advance Water-Flooding to Reduce the Stress Sensitivity Affect on Low Permeability Reservoir Development

2011 ◽  
Vol 361-363 ◽  
pp. 520-525
Author(s):  
Jun Feng Yang ◽  
Han Qiao Jiang ◽  
Han Dong Rui ◽  
Xiao Qing Xie
Keyword(s):  
Physical Simulation ◽  
Physical Property ◽  
Stress Sensitivity ◽  
Water Flooding ◽  
Low Permeability ◽  
Formation Pressure ◽  
Exponential Relationship ◽  
Low Permeability Reservoir ◽  
Reservoir Development ◽  
Water Cut

Physical simulation experiments were made to research on the stress sensitivity on physical property of low permeability reservoir rocks. The experimental results shown that effective pressure had good exponential relationship with reservoir permeability. Combining with materaial balance method, reservoir engineering and rational deducation was made to reserach on water-flooding timing of low permeability reservoir development. Several production targets were obtained by these method, such as formation pressure, water and oil production, water cut and so on. The results shown that advanced water-flooding was very important in low permeability reservoir development to reduce the bad impact of stress sensitivity on formation permeability and maintain formation pressure.

scholarly journals Reservoir characteristics and effective development technology in typical low-permeability to ultralow-permeability reservoirs of China National Petroleum Corporation

2021 ◽  
pp. 014459872110052
Author(s):  
Xizhe Li ◽  
Zhengming Yang ◽  
Shujun Li ◽  
Wei Huang ◽  
Jianfei Zhan ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Water Flooding ◽  
Low Permeability ◽  
Reservoir Characteristics ◽  
Well Pattern ◽  
China National Petroleum Corporation ◽  
Volume Fracturing ◽  
Effective Development ◽  
Oil Gas ◽  
Ultralow Permeability

Low-permeability to ultralow-permeability reservoirs of the China National Petroleum Corporation are crucial to increase the reserve volumes and the production of crude oil in the present and future times. This study aimed to address the two major technical bottlenecks faced by the low-permeability to ultralow-permeability reservoirs by a comprehensive use of technologies and methods such as rate-controlled mercury injection, nuclear magnetic resonance, conventional logging, physical simulation, numerical simulation, and field practices. The reservoir characteristics of low-permeability to ultralow-permeability reservoirs were first analyzed. The water flooding development adjustment mode in the middle and high water-cut stages for the low-permeability to ultralow-permeability reservoirs, where water is injected along the fracture zone and lateral displacement were established. The formation mechanism and distribution principles of dynamic fractures, residual oil description, and expanding sweep volume were studied. The development mode for Type II ultralow-permeability reservoirs with a combination of horizontal well and volume fracturing was determined; this led to a significant improvement in the initial stages of single-well production. The volume fracturing core theory and optimization design, horizontal well trajectory optimization adjustment, horizontal well injection-production well pattern optimization, and horizontal well staged fracturing suitable for reservoirs with different characteristics were developed. This understanding of the reservoir characteristics and the breakthrough of key technologies for effective development will substantially support the oil-gas valent weight of the Changqing Oilfield to exceed 50 million tons per year, the stable production of the Daqing Oilfield with 40 million tons per year (oil-gas valent weight), and the realization of 20 million tons per year (oil-gas valent weight) in the Xinjiang Oilfield.

The Combined Flooding of Dispersed Particle Gel and Surfactant for Conformance Control and EOR: From Experiment to Pilot Test

2021 ◽  
Author(s):  
Xia Yin ◽  
Tianyi Zhao ◽  
Jie Yi
Keyword(s):  
Oil Recovery ◽  
Formation Energy ◽  
High Salinity ◽  
Surfactant Solution ◽  
Pilot Test ◽  
Control Performance ◽  
Core Flooding ◽  
Displacement Efficiency ◽  
Conformance Control ◽  
And Performance

Abstract The water channeling and excess water production led to the decreasing formation energy in the oilfield. Therefore, the combined flooding with dispersed particle gel (DPG) and surfactant was conducted for conformance control and enhanced oil recovery in a high temperature (100-110°C) high salinity (>2.1×105mg/L) channel reservoir of block X in Tahe oilfield. This paper reports the experimental results and pilot test for the combined flooding in a well group of Block X. In the experiment part, the interfacial tension, emulsifying capacity of the surfactant and the particle size during aging of DPG were measured, then, the conformance control and enhanced oil recovery performance of the combined flooding was evaluated by core flooding experiment. In the pilot test, the geological backgrounds and developing history of the block was introduced. Then, an integrated study of EOR and conformance control performance in the block X are analyzed by real-time monitoring and performance after treatment. In addition, the well selection criteria and flooding optimization were clarified. In this combined flooding, DPG is applied as in-depth conformance control agent to increase the sweep efficiency, and surfactant solution slug following is used for improve the displacement efficiency. The long term stability of DPG for 15 days ensures the efficiency of in-depth conformance control and its size can increase from its original 0.543μm to 35.5μm after aging for 7 days in the 2.17×105mg/L reservoir water and at 110°C. In the optimization, it is found that 0.35% NAC-1+ 0.25% NAC-2 surfactant solution with interfacial tension 3.2×10-2mN/m can form a relatively stable emulsion easily with the dehydrated crude oil. In the double core flooding, the conformance control performance is confirmed by the diversion of fluid after combined flooding and EOR increases by 21.3%. After exploitation of Block X for 14 years, the fast decreasing formation energy due to lack of large bottom water and water fingering resulted in a decreasing production rate and increasing watercut. After combined flooding in Y well group with 1 injector and 3 producers, the average dynamic liquid level, daily production, and tracing agent breakthrough time increased, while the watercut and infectivity index decreased. The distribution rate of injected fluid and real-time monitoring also assured the conformance control performance. The oil production of this well group was increased by over 3000 tons. Upon this throughout study of combined flooding from experiment to case study, adjusting the heterogeneity by DPG combined with increasing displacement efficiency of surfactant enhanced the oil recovery synergistically in this high salinity high temperature reservoir. The criteria for the selection and performance of combined flooding also provides practical experiences and principles for combined flooding.

Compatibility evaluation of in-depth profile control agents in dominant channels of low-permeability reservoirs

2020 ◽  
Vol 194 ◽  
pp. 107529 ◽  
Author(s):  
Junjian Li ◽  
Ze Wang ◽  
Hanxu Yang ◽  
Hai'en Yang ◽  
Tianjiang Wu ◽  
...  
Keyword(s):  
Depth Profile ◽  
Low Permeability ◽  
Profile Control ◽  
Low Permeability Reservoirs

Priority Selection of Weak Gel Flooding Formula on Heterogeneous Reservoir

2014 ◽  
Vol 1073-1076 ◽  
pp. 2248-2251
Author(s):  
Wen Xiang Wu ◽  
Xin Song ◽  
Yue Fu ◽  
Peng Fei Yuan
Keyword(s):  
Gelation Time ◽  
High Viscosity ◽  
Development Stage ◽  
Water Flooding ◽  
Cross Linking ◽  
Heterogeneous Reservoirs ◽  
Weak Gel ◽  
Core Displacement ◽  
Selection Of ◽  
Gel System

Nowadays, most of the oilfields have been entered later development stage, it is difficult for reservoirs to depend on water flooding technology to improve recovery factor enormously. To satisfy deep flooding demand on heterogeneous reservoirs, the weak gel system is developed in the lab. Due to the mixture of organic chromium and HAPM, forming the organic weak gel system. HPAM concentration is from 1300mg/l to 1500mg/l and from 150mg/l to 210mg/l for cross-linking agent, the weak gel system formed stably with the high viscosity which is above 10000mp·s and moderate gelation time is from 45h to 130h.The best formula was selected with HPAM concentration 1500mg/l, and cross-linking agent concentration 210mg/l.The core displacement experiment shows the weak gel system has a well flooding effect on heterogeneous reservoirs, and its recovery rate increases 16.2%。

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