COUPLED FLUID FLOW AND GEOMECHANICS IN COALBED METHANE RECOVERY STUDY

2010 ◽  
Vol 24 (13) ◽  
pp. 1291-1294 ◽  
Author(s):  
ZHIJIE WEI ◽  
DONGXIAO ZHANG
Keyword(s):  
Fluid Flow ◽  
Coalbed Methane ◽  
Gas Adsorption ◽  
Methane Recovery ◽  
Flow Process ◽  
Fully Implicit ◽  
Recovery Study ◽  
Volume Method ◽  
Adsorption Desorption ◽  
The Mathematical Model

In this paper, we present a coupled fluid flow and geomechanics model for simulating coalbed methane recovery. In the model, the fluid flow process is simulated with a triple porosity/dual permeability representation, and the coupling effects of effective stress and matrix swelling/shrinkage approach are simulated with a coupled fluid flow, geomechanics and gas adsorption/desorption model. The mathematical model is implemented with a fully implicit finite volume method and simulation is conducted to evaluate the effect of coupled fluid flow, geomechanics, and gas adsorption/desorption.

scholarly journals Experimental research on desorption characteristics of gas-bearing coal subjected to mechanical vibration

2020 ◽  
Vol 38 (5) ◽  
pp. 1454-1466
Author(s):  
Xuexi Chen ◽  
Liang Zhang ◽  
Maoliang Shen
Keyword(s):  
Coalbed Methane ◽  
Gas Adsorption ◽  
Mechanical Vibration ◽  
Particle Diameter ◽  
Reference Value ◽  
Desorption Rate ◽  
Gas Desorption ◽  
Adsorbed Gas ◽  
Vibration Parameters ◽  
Adsorption Desorption

Mechanical vibration can induce coal and gas outburst accidents, and can also promote the exploitation of coalbed methane. In this paper, a vibration-adsorption-desorption experiment system was established, the effects of coal sample particle diameter, gas pressure, and vibration frequency on gas desorption were studied. Mechanical vibration can generate a shear force in the adsorbed gas and promote gas desorption, but there are appropriate vibration parameters. Within the range of experimental parameters, the larger the amplitude, the more favorable for gas desorption. The change rules of gas desorption rate and desorption quantity under different conditions are basically the same, showing a power function shape with time increase, and most of the desorption quantity was completed within the first 5 minutes. The gas desorption rate and desorption quantity were positively related to the gas adsorption pressure. The results have great reference value for preventing gas outbursts and promoting gas exploitation.

scholarly journals Simulasi aliran fluida pada proses enhanced coalbed methane

2018 ◽  
Vol 10 (3) ◽  
pp. 157
Author(s):  
Mohammad Resalto Pradewa ◽  
Retno Gumilang Dewi ◽  
Ucok W.R. Siagian
Keyword(s):  
Fluid Flow ◽  
Greenhouse Gases ◽  
Coalbed Methane ◽  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Flow Simulation ◽  
Methane Recovery ◽  
Enhanced Coalbed Methane ◽  
Flow Variables ◽  
And Storage

Fluid flow simulation on enhanched coalbed methane systemThe Enhanced Coalbed Methane (ECBM) process can be applied as a carbon capture and storage (CCS) technology for the mitigation of greenhouse gases emissions, by transferring CO2 emitted by stationary sources into ECBM field reservoirs. This CCS-ECBM integration is a novel technology that is aimed at reducing CO2 emission while simultaneously improving the energy supply security in Indonesia. This research studies the fluid flow in fractures/cleats in CBM reservoirs, which is a laminar flow under pressure gradient in accordance to Darcy's law. The objective of this research is to understand the mechanism of the integration between CCS and ECBM process via computer simulations. Gas components considered in the simulation include CH4 and CO2. Fluid flow variables in this research are permeability (k), porosity (ϕ), and gas saturation (S). Simulations are done using the FlexPDE version 5 software package. Simulation results indicate that all three variables influence the fluid flow mechanism in fractures/cleats during the injection of CO2 in ECBM process. Simulations which are run for 100 days predict that methane recovery is inversely proportional to porosity, with a recovery of 97.88% at a porosity of 0.017, and 37.16% at a porosity of 0.63.Keywords: greenhouse gases, CCS, ECBM, fractures, cleats Abstrak Proses Enhanced Coalbed Methane (ECBM) dapat diterapkan sebagai salah satu teknologi penangkapan dan penyimpanan karbon (Carbon Capture and Storage atau CCS) untuk mitigasi emisi gas rumah kaca, dengan cara menyalurkan CO2 dari sumber emisi stasioner ke dalam reservoir lapangan ECBM. Integrasi CCS-ECBM ini merupakan teknologi baru yang diharapkan mampu mengurangi emisi CO2 sekaligus meningkatkan ketahanan pasokan energi Indonesia. Penelitian ini mempelajari aliran fluida pada retakan (fractures/cleats) di dalam reservoir CBM yang merupakan aliran laminer di bawah gradien tekanan yang mengikuti hukum Darcy. Penelitian ini bertujuan memahami mekanisme integrasi CCS dengan proses ECBM melalui pendekatan simulasi komputer. Senyawa-senyawa yang ditinjau adalah CH4 dan CO2. Variabel-variabel aliran yang diperhitungkan dalam model mencakup permeabilitas (k), porositas (ϕ), dan saturasi gas (S). Simulasi dilakukan menggunakan perangkat lunak FlexPDE versi 5. Hasil simulasi menunjukkan bahwa mekanisme aliran dalam retakan dengan injeksi CO2 pada proses ECBM dipengaruhi oleh ketiga variabel yang ditinjau. Simulasi yang dijalankan selama 100 hari menunjukkan bahwa perolehan metana berbanding terbalik secara linier terhadap porositas, dengan perolehan sebesar 97,88% pada porositas 0,017 dan 37,16% pada porositas 0,63.Kata kunci: gas rumah kaca, CCS, ECBM, retakan, cleats

scholarly journals Transient Pressure Analysis of a Multiple Fractured Well in a Stress-Sensitive Coal Seam Gas Reservoir

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3849 ◽  
Author(s):  
Zuhao Kou ◽  
Haitao Wang
Keyword(s):  
Fluid Flow ◽  
Coalbed Methane ◽  
Radial Flow ◽  
Outer Region ◽  
Stress Sensitivity ◽  
Natural Fracture ◽  
Radial Fracture ◽  
Transient Pressure ◽  
Fractured Well ◽  
Adsorption Desorption

This paper investigates the bottom-hole pressure (BHP) performance of a fractured well with multiple radial fracture wings in a coalbed methane (CBM) reservoir with consideration of stress sensitivity. The fluid flow in the matrix simultaneously considers adsorption–desorption and diffusion, whereas fluid flow in the natural fracture system and the induced fracture network obeys Darcy’s law. The continuous line-source function in the CBM reservoir associated with the discretization method is employed in the Laplace domain. With the aid of Stehfest numerical inversion technology and Gauss elimination, the transient BHP responses are determined and analyzed. It is found that the main flow regimes for the proposed model in the CBM reservoir are as follows: linear flow between adjacent radial fracture wings, pseudo-radial flow in the inner region or Stimulated Reservoir Volume (SRV), and radial flow in outer region (un-stimulated region). The effects of permeability modulus, radius of SRV, ratio of permeability in SRV to that in un-stimulated region, properties of radial fracture wings, storativity ratio of the un-stimulated region, inter-porosity flow parameter, and adsorption–desorption constant on the transient BHP responses are discussed. The results obtained in this study will be of great significance for the quantitative analyzing of the transient performances of the wells with multiple radial fractures in CBM reservoirs.

scholarly journals Experimental study on the microscopic characteristics affecting methane adsorption on anthracite coal treated with high-voltage electrical pulses

2017 ◽  
Vol 36 (1-2) ◽  
pp. 170-181 ◽  
Author(s):  
Chuan-jie Zhu ◽  
Ximiao Lu ◽  
Bai-quan Lin ◽  
Fa-zhi Yan ◽  
Chang Guo ◽  
...  
Keyword(s):  
High Voltage ◽  
Coalbed Methane ◽  
Gas Adsorption ◽  
Gas Permeability ◽  
Electrical Pulse ◽  
Gas Migration ◽  
Methane Recovery ◽  
Enhanced Coalbed Methane Recovery ◽  
Anthracite Coal ◽  
Electrical Pulses

The low gas permeability of coal formations with limited coal pores and fractures leads to difficulty in coalbed methane exploration. High-voltage electrical pulse has a potential application in enhanced coalbed methane recovery. In this study, we discuss the microscopic characteristics of anthracite coals treated by high-voltage electrical pulse. We find that C, O, and other coal elements constituting oxygenic groups, which mainly account for gas adsorption, decreased slightly after high-voltage electrical pulse treatment, indicating that elemental variation may have little influence on gas adsorption. The scanning electron microscopy and low-pressure nitrogen gas adsorption (LP-N2GA) results show that the cumulative micropore volumes of high-voltage electrical pulse-treated coals were much larger than those of original coals. The mercury intrusion porosimetry results show that the cumulative macropore volumes, which act as gas migration channels in coal increased. Additionally, high-voltage electrical pulse-treated coals were found to have smaller entrapment areas, indicating that gas migration was enhanced.

scholarly journals Pore-Scale Lattice Boltzmann Simulation of Gas Diffusion–Adsorption Kinetics Considering Adsorption-Induced Diffusivity Change

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4927 ◽  
Author(s):  
Zhigao Peng ◽  
Shenggui Liu ◽  
Yingjun Li ◽  
Zongwei Deng ◽  
Haoxiong Feng
Keyword(s):  
Coalbed Methane ◽  
Gas Adsorption ◽  
Fluid Velocity ◽  
Gas Diffusion ◽  
Gas Production ◽  
Pore Scale ◽  
Desorption Process ◽  
Gas Diffusivity ◽  
Isotherm Adsorption ◽  
Adsorption Desorption

The diffusion–adsorption behavior of methane in coal is an important factor that both affecting the decay rate of gas production and the total gas production capacity. In this paper, we established a pore-scale Lattice Boltzmann (LB) model coupled with fluid flow, gas diffusion, and gas adsorption–desorption in the bi-dispersed porous media of coalbed methane. The Knudsen diffusion and dynamic adsorption–desorption of gas in clusters of coal particles were considered. Firstly, the model was verified by two classical cases. Then, three dimensionless numbers, Re, Pe, and Da, were adopted to discuss the impact of fluid velocity, gas diffusivity, and adsorption/desorption rate on the gas flow–diffusion–adsorption process. The effect of the gas adsorption layer in micropores on the diffusion–adsorption–desorption process was considered, and a Langmuir isotherm adsorption theory-based method was developed to obtain the dynamic diffusion coefficient, which can capture the intermediate process during adsorption/desorption reaches equilibrium. The pore-scale bi-disperse porous media of coal matrix was generated based on the RCP algorithm, and the characteristics of gas diffusion and adsorption in the coal matrix with different Pe, Da, and pore size distribution were discussed. The conclusions were as follows: (1) the influence of fluid velocity on the diffusion–adsorption process of coalbed methane at the pore-scale is very small and can be ignored; the magnitude of the gas diffusivity in macropores affects the spread range of the global gas diffusion and the process of adsorption and determines the position where adsorption takes place preferentially. (2) A larger Fickian diffusion coefficient or greater adsorption constant can effectively enhance the adsorption rate, and the trend of gas concentration- adsorption is closer to the Langmuir isotherm adsorption curve. (3) The gas diffusion–adsorption–desorption process is affected by the adsorption properties of coal: the greater the pL or Vm, the slower the global gas diffusivity decay. (4) The effect of the gas molecular adsorption layer has a great impact on the kinetic process of gas diffusion–adsorption–desorption. Coal is usually tight and has low permeability, so it is difficult to ensure that the gas diffusion and adsorption are sufficient, the direct use of a static isotherm adsorption equation may be incorrect.

scholarly journals The Influence of Different Types of Nanofluid on Thermal and Fluid Flow Performance of Liquid Cold Plate

2018 ◽  
Vol 7 (4.35) ◽  
pp. 148 ◽  
Author(s):  
Nur Irmawati Om ◽  
Rozli Zulkifli ◽  
P. Gunnasegaran
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Pressure Drop ◽  
Volume Fraction ◽  
Cold Plate ◽  
Governing Equations ◽  
Flow And Heat Transfer ◽  
Different Types ◽  
Volume Method

The influence of utilizing different nanofluids types on the liquid cold plate (LCP) is numerically investigated. The thermal and fluid flow performance of LCP is examined by using pure ethylene glycol (EG), Al2O3-EG and CuO-EG. The volume fraction of the nanoparticle for both nanofluid is 2%. The finite volume method (FVM) has been used to solved 3-D steady state, laminar flow and heat transfer governing equations. The presented results indicate that Al2O3-EG able to provide the lowest surface temperature of the heater block followed by CuO-EG and EG, respectively. It is also found that the pressure drop and friction factor are higher for Al2O3-EG and CuO-EG compared to the pure EG.

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