Experimental Method to Simulate Coal Fines Migration and Coal Fines Aggregation Prevention in the Hydraulic Fracture

2013 ◽  
Vol 101 (1) ◽  
pp. 17-34 ◽  
Author(s):  
Y. S. Zou ◽  
S. C. Zhang ◽  
J. Zhang
Keyword(s):  
Experimental Method ◽  
Hydraulic Fracture ◽  
Fines Migration ◽  
Coal Fines

Coal fines migration: A holistic review of influencing factors

2021 ◽  
pp. 102595
Author(s):  
Faisal Ur Rahman Awan ◽  
Muhammad Arif ◽  
Stefan Iglauer ◽  
Alireza Keshavarz
Keyword(s):  
Influencing Factors ◽  
Fines Migration ◽  
Holistic Review ◽  
Coal Fines

scholarly journals An Experimental Study on Coal Fines Migration during Single Phase Water Flow

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Wenlong Han ◽  
Yanbin Wang ◽  
Jingjing Fan ◽  
Yong Li ◽  
Xiang Wu ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Water Flow ◽  
Coalbed Methane ◽  
Confining Pressure ◽  
Fines Migration ◽  
Reservoir Permeability ◽  
Confining Pressures ◽  
Coal Fines ◽  
Flow Velocities ◽  
Loss Rates

Coal fines migration and intrusion in coal fractures affect coalbed methane (CBM) wells performance by reducing reservoir permeability and production continuity. Physical simulations are conducted to investigate the permeability variation under different diameter coal fines intrusion at various flow velocities and confining pressures. The results show that the conductivity of fractures is dramatically reduced and hardly recover to its initial condition after coal fines intrusion. The permeability after coal fines intrusion (Pcfi) has no direct correlation with the increase of flooding velocity, while decreases with the increase of confining pressures. The fractures can be totally blocked by coal fines, while penetration also happened during the flooding process, causing permeability fluctuation. The permeability loss rates value for 80-120 mesh coal fines intrusion are generally <60% compared with the initial permeability, including the flow velocity of 2, 3, 4, 6, 8, and 10 mL/min with confining pressure of 6 MPa and the confining pressure of 2, 3, 4, 5, and 6 MPa with flow velocity of 3 mL/min. However, under 120+ mesh coal fines condition, the permeability loss rates are higher than 85% under most flow velocities and confining pressures. When coal fines become smaller, the permeability loss rates decrease to be lower than 45%, and part the coal fines are discharged with the water flow. Thus, coal fines proper dischargement can partly maintain the reservoir permeability during coalbed methane production. The results would be useful in understanding coal fines intrusion behaviors and its controlling strategies during CBM drainage.

Coal Fines Migration, Deposition, and Output Simulation during Drainage Stage in Coalbed Methane Production

2021 ◽  
Vol 35 (6) ◽  
pp. 4901-4913
Author(s):  
Wenlong Han ◽  
Yanbin Wang ◽  
Yong Li ◽  
Xiaoming Ni ◽  
Xiang Wu ◽  
...  
Keyword(s):  
Methane Production ◽  
Coalbed Methane ◽  
Fines Migration ◽  
Coalbed Methane Production ◽  
Coal Fines

scholarly journals Numerical Simulation Study of Fines Migration Impacts on an Early Water Drainage Period in Undersaturated Coal Seam Gas Reservoirs

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xiaolong Peng ◽  
Suyang Zhu ◽  
Zhenjiang You ◽  
Zhimin Du ◽  
Peng Deng ◽  
...  
Keyword(s):  
Coal Seam ◽  
History Matching ◽  
Generation Model ◽  
Water Drainage ◽  
Coal Seam Gas ◽  
Fines Migration ◽  
Deviation Factor ◽  
Water Rate ◽  
Deposition Processes ◽  
Coal Fines

Coal fines migration exerts negative impacts on early water drainage of undersaturated coal seam gas (CSG) reservoirs. The complicated migration process results in ineffective and inaccurate forecast of coal fines production. Hence, a robust modelling tool is required to include the mechanisms of fines migration and to predict their impacts on rock and production. In this paper, fines migration in coal is categorized into three stages: generation, migration, and deposition processes. The corresponding models for different stages are established, including (1) a fines generation model, (2) the maximum fines-carrying concentration model and deviation factor of the modified Darcy model, (3) a fines deposition model, and (4) a dynamic permeability and porosity model. The above models are coupled with a water flow model, solved numerically using the finite difference method. Then, two dewatering strategies, including fast and moderate depressurization, are compared using the proposed models to study their effects on coal properties and following production. Finally, the production history of a CSG well in the Qinshui Basin, China, is utilized for history matching in a field case study. The simulation results indicate that new fines will be generated in a fast depressurization process and the water rate decline reduces the cleat permeability significantly. The newly generated fines can enhance the permeability temporarily, but they will block the flow channels and bring serious damage to the permeability when the water rate declines. The moderate depressurization strategy can produce the coal fines in a continuous mode, and the formation damage induced by fines deposition can be reduced to the acceptable level, which is the more reliable way to maintain well productivity. In addition, multiple well shut-in can trigger the irreversible fines deposition, reduce the permeability, and decrease the production rate.

An experimental study of coal-fines migration in Coalbed-methane production wells

2015 ◽  
Vol 26 ◽  
pp. 1542-1548 ◽  
Author(s):  
Guoqing Han ◽  
Kegang Ling ◽  
Huaxiao Wu ◽  
Fei Gao ◽  
Feng Zhu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Methane Production ◽  
Coalbed Methane ◽  
Fines Migration ◽  
Production Wells ◽  
Coalbed Methane Production ◽  
Coal Fines

scholarly journals Experimental Investigation of the Impact of Coal Fines Migration on Coal Core Water Flooding

2018 ◽  
Vol 10 (11) ◽  
pp. 4102 ◽  
Author(s):  
Dapeng Gao ◽  
Yuewu Liu ◽  
Tianjiao Wang ◽  
Daigang Wang
Keyword(s):  
Differential Pressure ◽  
Water Flooding ◽  
Two Phase ◽  
Fines Migration ◽  
Equivalent Permeability ◽  
The Core ◽  
Core Samples ◽  
Coal Rock ◽  
Phase Water ◽  
Coal Fines

Coalbed Methane (CBM) has become an important gas resource in recent decades. The brittle property of coal matrix and overactive operation make the migration of coal fines inevitable. Blockage by coal fines that plugs flow paths is a non-negligible issue that results in a significant decline in gas production. By setting different experimental conditions with the following factors—coal fines concentration of the mixture displacing fluids, constant flow pump rate, inlet pressure, outlet pressure and confining pressure—six experimental schemes were designed to investigate the two-phase water and coal fines flow in natural core samples. When the differential pressure and flooding flow reach a pseudo-steady status, the equivalent permeability of coal samples can be approximately calculated considering coal fines migration. Furthermore, the influences of coal fines migration on the cleat opening and permeability variation are analyzed in the porous coal medium. The study will benefit CBM development and save pump maintenance costs. In this work, we found that maintaining the differential pressure for a longer period may result in new cleat openings and severe coal rock damage during the single-phase water flooding process. While coal fines may plug some natural cleats and pores, especially in the core samples with micro-cleats during the two-phase flooding stage, coal fines migration significantly reduces the equivalent permeability and dewatering ability of the coal rock in the earlier flooding. While enlarging the differential pressure in two-phase water and fines flooding, breakthrough of coal fines from the samples contributes to widened cleats. While coal fines are difficult to flood into the core pores for low-permeability core samples, coal fines gather in the inlet, and it is also difficult to reach the pseudo-steady status even under higher differential pressure. The damage to permeability mainly occurs in the early stage of coal fines migration, and an abrupt increase in the flow velocity can damage reservoirs and induce substantial coal fines generation. Thus, maintaining a stable effective strength and a controlled depressurization rate during drainage can effectively constrain coal fines output and decrease permeability damage within coal reservoirs.

Experimental Method in Antiquity.

1964 ◽  
Vol 19 (6) ◽  
pp. 419-419
Author(s):  
Frank P. Jones
Keyword(s):  
Experimental Method

Monitoring bedload sediment transport in a pre-Alpine river: an experimental method

2017 ◽  
Vol 43 ◽  
pp. 57-63 ◽  
Author(s):  
Monica Papini ◽  
Vladislav Ivov Ivanov ◽  
Davide Brambilla ◽  
Diego Arosio ◽  
Laura Longoni
Keyword(s):  
Sediment Transport ◽  
Experimental Method ◽  
Alpine River ◽  
Bedload Sediment

“I stay at work for you, you stay at home for us.” Does this Covid-19 campaign work for the youth in Asia?

2020 ◽  
Vol 8 (2) ◽  
pp. 161-175
Author(s):  
Jappy Fanggidae ◽  
Ridolof Batilmurik ◽  
Pieter Samadara
Keyword(s):  
Experimental Method ◽  
Social Distancing ◽  
Asian Context ◽  
The Relationship ◽  
At Home

This study investigated the relationship between guilt appeal and compliance with social distancing measures. We proposed that the relationship is double mediated by empathy and responsibility for the unfortunate people who have suffered from COVID-19. This research is novel to an extent as an experimental method is used in the Asian context. The results exhibited that guilt positively affected compliance with social distancing measures. The respondents were directly or indirectly compliant due to the emotions of empathy and responsibility. The theoretical and practical contributions of this study were presented.

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