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

Han, Guoqing; Ling, Kegang; Wu, Huaxiao; Gao, Fei; Zhu, Feng; Zhang, Ming

doi:10.1016/j.jngse.2015.06.012

Cited by 40 publications

(18 citation statements)

References 20 publications

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“…The second reason is that the gas flow rate is much lower than that of conventional gas. Therefore, it can be assumed that effects of gas flow on coal fine can be ignored (Mitchell and Leonardi 2016;Han et al 2015).…”

Section: Basic Assumptionsmentioning

confidence: 99%

“…Researches including theory modeling, experiment exploration and production analysis have established the fundamental of coal fine generation in coal (Han et al 2015;Yao et al 2016). The generation mechanism of coal fine during drilling, fracturing and CBM production has been well summarized, and its impacts on production performance of CBM wells have also been preferably considered.…”

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confidence: 99%

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Modeling of Coal Fine Migration During CBM Production in High-Rank Coal

Zhu

Peng

et al. 2017

Transp Porous Med

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During CBM (coalbed methane) production, the interaction of coal fracture surface with water flow commonly generates and starts coal fine flow. Part of flowing coal fines deposit in coal fracture system due to water production reduction and methane production increase. The fine sedimentation results in the reduction of coal permeability and well productivity. Despite the increasing awareness of the importance of fine migration, limited research has been carried out on the flow model of coal fine coupled with water and gas. In this paper, a flow model of coal fine is established coupled with water and gas flow, taking coal fine generation, migration and sedimentation process into consideration. Then, case simulations are conducted to illustrate effects of water production schedule, permeability performance and gas content on production performance in flow model. The simulation results indicate that methane rate with the lowest initial water rate is observed to have the highest production in late production period. This is mainly due to the reason that the low water flow cannot generate and start the flow of coal fine. Further, the case with high initial water production has faster gas and water flow rate, thus higher coal fine generation rates, which can improve well productivity at earlier production period. As water production declines quickly, both permeability and production performance decrease, which leads to the loss of well productivity. Meanwhile, higher gas content will lead to a faster water production decline at late production period. This indicates that a portion of coal fines plugged in the fracture as water production deceases and the CBM reservoir with high gas content should not adopt a high initial water production schedule.

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Section: Basic Assumptionsmentioning

confidence: 99%

mentioning

confidence: 99%

Modeling of Coal Fine Migration During CBM Production in High-Rank Coal

Zhu

Peng

et al. 2017

Transp Porous Med

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“…Speci cally, India has tremendous potential for the extraction of methane from coal beds (Rathi et al 2019). Concurrently, the CBM reservoirs with clay mineral deposits are highly susceptible to reservoir formation damage due to nes (inorganic minerals) and coal nes (tiny fragment from broken coal matrix) migration under hydrodynamic and thermodynamic forces Guo et al 2018;Huang et al 2018;Zhao et al 2018;Zhao et al 2016;Valentim et al 2016;Han et al 2015;Bai et al 2015;Guo et al 2015;Zeinijahromi et al 2012;Seidle 2011). Actually, kaolinite clay minerals are located in several sedimentary formations, especially in sandstone and carboniferous rocks, and moreover, kaolinite occurs through dissolution of feldspar at extreme temperature and geochemical alterations (Mahalingam et al 2019;Kanimozhi et al 2019a).…”

Section: Introductionmentioning

confidence: 99%

Permeability Damage and Supercritical Fluid Storage in the Cauvery Basin Neyveli Lignite Bed Containing Kaolinite Deposits during Alternative Injection of Brine and CO2

Rajkumar

Antony

Mahalingam³

et al. 2020

Preprint

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A laboratory based investigation has been conducted on permeability damage and CO2 storage or retention in the lignite core during alternative injection of brine and supercritical carbon dioxide. Moreover, anthracite and bituminous coal beds were focused by the scientific community for effective production and reservoir formation damage study. But, now-a-days, lignite based coal bed methane reservoirs have attracted attention for productive exploitation and formation collapse investigation. Hence, for this purpose, a single component injection two phase (Brine + Supercritical CO2) coreflood test analysis under alternative injections were performed to investigate the occurrence of lignite structural collapse, permeability damage, injectivity decline and CO2 retention as well. The experimental study reveals that, due to gravity segregation there is a high rate of fluid saturation in lignite core and also, moderate level of heat transfer coefficient was also noted. Also, lignite core structural collapse under the brine and supercritical CO2 injection at different velocities resulted in huge volume of coal and kaolinite fines concentration. Kaolinite and coal fines migration resulted in pressure change and permeability decline in lignite core. The suspensions produced were passed to microstructural analysis and it revealed that kaolinite fine particle tends to possess a leaflet geometrical structure, which obstructed the cleats and restricted the fluid flow. Subsequently, hysteresis modelling (Pranesh 2018) was applied to this problem to quantify the amount of CO2 retention in lignite core. Additionally, statistical model, multiple linear regression was applied to this problem to validate the experimental model, which showed good agreement.

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“…Fines produced from the CSG well are significantly different in particle size, micromorphology, mineralogy, and generation modes during different stages of production [18,19]. Owing to the complexity of fines generation and migration, it is difficult to establish a robust mathematical model to evaluate the impacts of coal fines systematically and quantitatively.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2019

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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.

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

Cited by 40 publications

References 20 publications

Modeling of Coal Fine Migration During CBM Production in High-Rank Coal

Modeling of Coal Fine Migration During CBM Production in High-Rank Coal

Permeability Damage and Supercritical Fluid Storage in the Cauvery Basin Neyveli Lignite Bed Containing Kaolinite Deposits during Alternative Injection of Brine and CO2

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

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