scholarly journals The experimental investigation of the HPAM/phenolic resin deep profile system in fractured low-permeability reservoirs

2021 ◽  
Vol 252 ◽  
pp. 02078
Author(s):  
Wei Zhou ◽  
Daiyin Yin ◽  
Yazhou Zhou
Keyword(s):  
Control System ◽  
Control Systems ◽  
Phenolic Resin ◽  
Good Effect ◽  
Low Permeability ◽  
Low Permeability Reservoir ◽  
Shearing Rate ◽  
Profile Control ◽  
Deep Profile ◽  
Low Permeability Reservoirs

The problem of injected water channeling along fractures exists in the process of water injection in fractured low permeability reservoir, aimed at this problem, deep profile control technology applies to plug fractures to improve the recovery of low permeability reservoir. In this paper, partially hydrolyzed polyacrylamide (HPAM) is used as water-plugging/profile-modifying agent and phenolic resin as crosslinker agent. Several profile control systems are tested to find the one which is suitable for fractured low permeability reservoirs. The performances of profile control systems are evaluated, and effects of formation water salinity, that of shearing rate and that of temperature on the performance are studied. Finally, in order to study effects of this profile control system on displacing oil, flowability experiment and core displacement experiment are applied. It shows that with the increase of salinty of prepared water and the increase of the shearing rate, the viscosity of this system decreases. With the increase of temperature, the gelling time shortens, the viscosity increases, but the stability weekens. This kind of profile control system has a good effect on plugging fractures of low permeability cores. After water flooding, this kind of profile control system is injected into cores, the recovery ratio can increase 3.5%. So the profile control system composed of HPAM/ phenolic resin can apply to deep profile control in fractured low permeability reservoir to enhance oil recovery.

scholarly journals Experimental Research on the Optimization and Evaluation of the Polymer/Chromium-Ion Deep Profile Control System for the Fractured Low-Permeability Reservoirs

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1021
Author(s):  
Daiyin Yin ◽  
Shuang Song ◽  
Qi Xu ◽  
Kai Liu
Keyword(s):  
Molecular Weight ◽  
Control System ◽  
High Molecular Weight ◽  
Low Molecular Weight ◽  
Low Permeability ◽  
Chromium Ion ◽  
Oil Displacement ◽  
Profile Control ◽  
Deep Profile ◽  
Plugging Performance

The matrix/fracture conductivity of a fractured low-permeability reservoir is variable, and its heterogeneity is serious. When carrying out deep profile control measures, it is difficult to inject under the premise of ensuring the plugging effect. According to the characteristics of the fractured low-permeability reservoir in Chaoyanggou Oilfield, the polymer/chromium ion deep profile control system was optimized via a viscosity evaluation experiment, liquidity experiment and oil displacement experiment. The experimental results show that the high molecular weight main agent/low concentration system and low molecular weight main agent/high concentration system can meet the gel strength requirement. The evaluation results of the injection ability and plugging performance of the fractured low-permeability core show that a high molecular weight profile control system is difficult to inject, while a low molecular weight profile control system has a poor plugging performance and high cost after simulated shear. Therefore, the formulation of the profile control system was determined to be a polymer with a molecular weight of 16 million g·mol−1 as the main agent with a concentration of 1000–1500 mg·L−1. As assisting agents, the concentrations of thiourea, NaCl and NaHCO3 were 900 mg·L−1, 800 mg·L−1 and 700 mg·L−1, respectively. The plugging rate of the system was 87.6%, and the resistance coefficient was 19.2. Finally, a fractured low-permeability core model with parallel long cores was designed, and the optimal profile control system was used for the core oil-displacement experiment. Compared with the water-flooding experiment, the plugging rate can be increased by 6.9–8.0%.

scholarly journals Study on the response characteristics of oil wells after deep profile control in low permeability fractured reservoirs

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 832-838 ◽  
Author(s):  
Lijun Lin ◽  
Wei Lin
Keyword(s):  
Fractured Reservoirs ◽  
Oil Production ◽  
Oil Wells ◽  
Low Permeability ◽  
Response Characteristics ◽  
Well Pattern ◽  
Profile Control ◽  
Deep Profile ◽  
Low Permeability Reservoirs ◽  
Oilfield Development

AbstractThe rhombus inverted nine-spot well pattern is often adopted in low permeability oilfield development, which has the advantage of high oil production rate and flexible adjustment. Due to the strong heterogeneity of the low permeability reservoirs, the oil wells along the fracture direction are heavily water-flooded and the water cut rises quickly, and the oil wells on both sides of fractures have no response to water injection. Hence, deep profile control is an effective way to solve this kind of plane contradiction, and is widely applied in the low permeability oilfield development. However, because of the asymmetry of the rhombus inverted nine-spot well pattern and the heterogeneity of the low permeability reservoirs, there are differences in the response characteristics of oil wells at different locations after deep profile control. In this paper, combined with physical experiments and numerical simulations, we analyzed oil increment, the distribution of streamlines and slugs of wells at different locations before and after deep profile control, and evaluated the response characteristics of oil wells of rhombus inverted nine-spot well pattern after deep profile control in low permeability fractured reservoirs. It is concluded that the effect of increasing oil production of the side wells is better than that of the angle wells after deep profile control, and the response sequence is side well, angle well in short axis, and angle well in long axis, which is also verified by the practical results of deep profile control in Daqing Oilfield.

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

scholarly journals Optimal Inflow Performance Relationship Equation for Horizontal and Deviated Wells in Low-Permeability Reservoirs

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Liqiang Wang ◽  
Zhengke Li ◽  
Mingji Shao ◽  
Yinghuai Cui ◽  
Wenbo Jing ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Superposition Principle ◽  
Horizontal Wells ◽  
Low Permeability ◽  
Flow Function ◽  
Low Permeability Reservoir ◽  
Inflow Performance ◽  
Low Permeability Reservoirs ◽  
Performance Equation ◽  
Deviated Wells

After Vogel proposed a dimensionless inflow performance equation, with the rise of the horizontal well production mode, a large number of inflow performance relationship (IPR) equations have emerged. In the productivity analysis of deviated and horizontal wells, the IPR equation proposed by Cheng is mainly used. However, it is still unclear whether these inflow performance models (such as the Cheng, Klins-Majcher, Bendakhlia-Aziz, and Wiggins-Russell-Jennings types) are suitable for productivity evaluations of horizontal and deviated wells in low-permeability reservoirs. In-depth comparisons and analyses have not been carried out, which hinders improvements in the accuracy of the productivity evaluations of horizontal wells in low-permeability reservoirs. In this study, exploratory work was conducted in two areas. First, the linear flow function relationship used in previous studies was improved. Based on the experimental pressure-volume-temperature results, a power exponential flow function model was established according to different intervals greater or less than the bubble point pressure, which was introduced into the subsequent derivation of the inflow performance equation. Second, given the particularity of low-permeability reservoir percolation, considering that the reservoir is a deformation medium, and because of the existence of a threshold pressure gradient in fluid flow, the relationship between permeability and pressure was changed. The starting pressure gradient was introduced into the subsequent establishment of the inflow performance equation. Based on the above two aspects of this work, the dimensionless IPR of single-phase and oil-gas two-phase horizontal wells in a deformed medium reservoir was established by using the equivalent seepage resistance method and complex potential superposition principle. Furthermore, through regression and error analyses of the standard inflow performance data, the correlation coefficients and error distributions of six types of IPR equations applicable to deviated and horizontal wells at different inclination angles were compared. The results show that the IPR equation established in this study features good stability and accuracy and that it can fully reflect the particularity of low-permeability reservoir seepage. It provides the best choice of the IPR between inclined wells and horizontal wells in low-permeability reservoirs. The other types of IPR equations are the Wiggins-Russell-Jennings, Klins-Majcher, Vogel, Fetkovich, Bendakhlia-Aziz, and Harrison equations, listed here in order from good to poor in accuracy.

scholarly journals Study on the Influential Factors of CO2 Storage in Low Permeability Reservoir

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 344
Author(s):  
Ping Yue ◽  
Rujie Zhang ◽  
James J. Sheng ◽  
Gaoming Yu ◽  
Feng Liu
Keyword(s):  
Carbon Dioxide ◽  
Co2 Storage ◽  
Ordos Basin ◽  
Influential Factors ◽  
Low Permeability ◽  
Geological Storage ◽  
Co2 Geological Storage ◽  
Low Permeability Reservoir ◽  
Low Permeability Reservoirs ◽  
Breakthrough Pressure

As the demands of tight-oil Enhanced Oil Recovery (EOR) and the controlling of anthropogenic carbon emission have become global challenges, Carbon Capture Utilization and Sequestration (CCUS) has been recognized as an effective solution to resolve both needs. However, the influential factors of carbon dioxide (CO2) geological storage in low permeability reservoirs have not been fully studied. Based on core samples from the Huang-3 area of the Ordos Basin, the feasibility and influential factors of geological CO2 sequestration in the Huang-3 area are analyzed through caprock breakthrough tests and a CO2 storage factor experiment. The results indicate that capillary trapping is the key mechanism of the sealing effect by the caprock. With the increase of caprock permeability, the breakthrough pressure and pressure difference decreased rapidly. A good exponential relationship between caprock breakthrough pressure and permeability can be summarized. The minimum breakthrough pressure of CO2 in the caprock of the Huang-3 area is 22 MPa, and the breakthrough pressure gradient is greater than 100 MPa/m. Huang-3 area is suitable for the geological sequestration of CO2, and the risk of CO2 breakthrough in the caprock is small. At the same storage percentage, the recovery factor of crude oil in larger permeability core is higher, and the storage percentage decreases with the increase of recovery factor. It turned out that a low permeability reservoir is easier to store CO2, and the storage percentage of carbon dioxide in the miscible phase is greater than that in the immiscible phase. This study can provide empirical reference for caprock selection and safety evaluation of CO2 geological storage in low permeability reservoirs within Ordos Basin.

scholarly journals Study on three phase foam for Enhanced Oil Recovery in extra-low permeability reservoirs

2018 ◽  
Vol 73 ◽  
pp. 55 ◽  
Author(s):  
Ming Zhou ◽  
Juncheng Bu ◽  
Jie Wang ◽  
Xiao Guo ◽  
Jie Huang ◽  
...  
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Foam Stability ◽  
Temperature Tolerance ◽  
Resistance Coefficient ◽  
Low Permeability ◽  
Displacement Efficiency ◽  
Three Phase ◽  
Profile Control ◽  
Low Permeability Reservoirs

Poly (MSt-MMA) nanosphere as foam stabilizing agent was synthesized by emulsion polymerization. The three phase foam was prepared with Disodium 4-Dodecyl-2,4′-Oxydiben Zenesulfonate (DOZS) as foaming agent, Hydrolyzed Polyacrylamide (HPAM) and synthesized poly (MSt-MMA) nanospheres as the mixed foam stabilizing agents. It had outstanding foaming performance and foam stability. The optimal three phase foam system consisting of 0.12 wt% HPAM, 0.04 wt% poly (MSt-MMA) nanospheres and 0.12 wt% DOZS by orthogonal experiment, had high apparent viscosity, which showed that three components had a very good synergistic effect. The three phase foam’s temperature tolerance and salt tolerance were researched in laboratory tests. Flooding oil experiment showed that the average displacement efficiency of three phase foam system was 16.1 wt% in single core experiments and 21.7 wt% in double core experiments. Resistance coefficient of low permeability core was more than those of high permeability core, but their residual resistance coefficients were small. The results of core experiment and pilot test indicated that the three phase foam had good profile control ability and generated low damage to the low permeability layer for extra-low permeability reservoirs. Three phase foam flooding has great prospects for Enhanced Oil Recovery (EOR) in extra-low permeability reservoirs.

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