Methane Desorption Research Articles

Enhancing shale gas recovery and CO2 sequestration: Microscopic mechanisms of adsorption and diffusion in shale pores

The global energy imbalance has created significant challenges and environmental consequences. Integrating carbon sequestration with shale gas development provides a promising solution to address both issues simultaneously. This study explores the adsorption, desorption, and diffusion behaviors of methane and CO2 in shale pores using a high-precision, high-pressure adsorption apparatus alongside molecular simulation techniques. Results demonstrate that CO2 shows a markedly higher adsorption capacity in shale pores than methane, particularly at high pressures. Simulations reveal that CO2 molecules nearly saturate pore spaces at pressures above 10 MPa. Methane's diffusion coefficient, initially high at low pressures, drops sharply with increasing pressure, decreasing by approximately 90% from 5.6 × 10−10 m2/s at 154 psi to 1.38 × 10−11 m2/s at 1032 psi. Conversely, CO2 diffusion remains stable under pressure changes, suggesting that methane diffusion is constrained by intermolecular interactions at high pressures, while CO2 retains stable movement. Under a reservoir condition of 30 MPa with adsorbed CH4, CO2 injection at varying pressures continues to enhance CO2 adsorption, underscoring CO2's dual role in boosting shale gas recovery while achieving carbon sequestration. This study highlights CO2-methane displacement mechanisms, providing theoretical insight that support both effective shale gas recovery and CO2 storage.

Methane Desorption-Diffusion Behaviors in Micropores of Coal under Different Water Displacement Pressures.

Hydraulic fracturing not only enhances the flow conductivity of coal seams but also transforms the CH4 adsorbed in coal seams into free CH4 and then outputs it via the desorption-diffusion process, thus improving the output quantity and efficiency of CH4. In this paper, taking the coal from Changping mine in Shanxi as the research object, the 3D macromolecule model of coal was established by using analytical test experiments, and the molecular dynamics simulation method of desorption and diffusion was applied to study the characteristics of methane desorption rate and diffusion behaviors under different driving water pressures through the parameters of gas-water concentration distribution, desorption and diffusion rates, and the interaction energies between the coal and the gas-liquid. The results show that the water drive can increase the desorption rate of methane. With the increase of methane adsorption pressure, the desorption effect of water drive becomes stronger and then weaker. The desorption effect of water drive was best when the methane adsorption pressure was 5 MPa and the pressure difference was 2 MPa. Generally, the water drive promoted the methane diffusion, but if the water drive time was too long, it formed a water plug, and the water drive methane inhibited the diffusion. In shallow reservoirs, water drive can obviously promote the desorption-diffusion of methane. The binding energy between CH4 molecules is mainly composed of the repulsive force, while that between water molecules is mainly the adsorption force. In the binding energy between CH4 molecules and coal structures, the van der Waals (VDW) force accounts for 99% of the effect; in the binding energy between water molecules and coal structures, the electrostatic force contributes 84% to ∼88% thereto. The VDW force is significantly influenced by the pressure, while the electrostatic force is slightly affected. As the water displacement differential pressure is increased, the binding energy between CH4 molecules and coal structures decreases.

Numerical Analysis of the Influence of Preadsorbed Water on Methane Transport in Crushed Shale

Summary Methane migration in shale is affected by preadsorbed water. To understand this effect, we examined several key parameters, including the effective pore diameter Le, the pore volume distribution of Le, the effective porosity ϕe, the equivalent particle diameter da, and the water film thickness h. Using these parameters, we established an equivalent relationship linking the particle packing da and the Le and the ϕe of the capillary pores within a unit-length cuboid of particles. Based on this relationship, a conceptual model was developed to simulate methane adsorption and transport in partially saturated crushed shale, incorporating parameter estimation for the tangential momentum adjustment factor δ and methane desorption rate coefficient kd, where δ characterizes the slip flow intensity and kd is related to the Langmuir adsorption constant. The finite element method was used to calculate the methane permeability ke, Knudsen diffusion coefficient Dke, surface diffusion coefficient Ds, and adsorption phase transition rate Rm, which are all affected by adsorbed water. The model’s numerical results were validated through comparison with the results from adsorption experiments. These results revealed three distinct regions in the trend of the variation in δ with Le: a rapid increase in Region I (Le < 10 nm), a slowing increase in Region II (10 ≤ Le ≤ 100 nm), and a gradual increase in Region III (Le > 100 nm). In addition, kd is positively correlated with da. kd is also correlated with water saturation S; specifically, kd decreases when S ≤ 12%, increases when S = 12% to 45.8%, and decreases again when S exceeds 45.8%. The results also reveal overall negative correlations between h and ke, Dke, Ds and Rm. Furthermore, the rates of change in ke, Dke, Ds and Rm with increasing ε (ε is the bending coefficient associated with adsorbed water) range from 7.5% to 49.4%. Similarly, ke, Dke, and Ds increase by factors of 0.73–7.19 with increasing χ (χ is the coverage rate of the adsorbed water film). Additionally, as the adsorption time t increases, Ds initially increases rapidly, followed by a gradual increase. Between t = 500 seconds and 1,500 seconds, the rate of change in Ds decreases by 20%. Rm shows a three-stage relationship with t, namely, a rapid decrease from t = 0 seconds to 500 seconds, a steady decrease from 500 seconds to 1,000 seconds, and a stabilization from 1,000 seconds to 1,500 seconds, with Rm ranging from 1.10×10-11 mol/(m3·s) to 9.45×10-11 mol/(m3·s) overall. Ds increases with the adsorption amount ratio Ed (Ed is the ratio of the adsorption amount at t to the equilibrium adsorption amount). As Ed ranges from 0.2 to 0.6, the rate of change in Ds increases by 87% to 100%. Furthermore, Rm is negatively linearly correlated with Ed.

Thermodynamic modeling of coal-gas interactions and desorption temperature analysis

This research developes an innovative thermodynamic coupling model for gas-bearing coal, improving temperature change simulations during coalbed methane desorption. The model distinctively integrates adsorption/desorption heat effects, free gas expansion, dynamic diffusion, the Klinkenberg effect, and moisture influence, offering a more comprehensive perspective of thermodynamic behavior. Comparisons with empirical data and previous models demonstrate that the predicted temperature changes closely match experimental results, indicating superior accuracy. The investigation finds a 23.51 % increase in desorption temperature as gas pressure rises from 0.4 MPa to 1.2 MPa, with temperature changes following the sequence CO2 > CH4 > N2, in the ratio ΔT(CO2): ΔT(CH4): ΔT(N2) = 1.76: 1.35: 1. Adsorbed gas desorption and free gas expansion are recognized as the primary drivers, especially near 0.5 MPa, where adsorbed gas contributes nearly 70 %. Sensitivity to variables such as gas pressure, adsorption heat, and permeability diminishes over time, with moisture exerting minimal impact. The study highlights a close thermodynamic connection between temperature changes and gas outbursts, proposing temperature variation as an reliable indicator for predicting and evaluating outburst risks. These findings enhance understanding of coalbed methane desorption and provide new theoretical foundations for efficient resource development and disaster prevention.

Energy and spectroscopic parameters of neutral and cations isomers of the CnH2 (n = 2-6) families using high-level ab-initio approaches.

Cationic species, previously detected from ion-induced desorption of solid methane by plasma desorption mass spectrometry (PDMS), and neutral species, are investigated using high-level ab-initio approaches. From a set of 25 cationic and 26 neutral structures belonging to CnH2 (n = 2-6) families, it was obtained the energy, rotational constants, harmonic vibrational frequency, charge distribution and excitation energies. The ZPVE-corrected energies, at CCSD(T)-F12; CCSD(T)-F12/RI/(cc-pVTZ-F12, cc-pVTZ-F12-CABS, cc-pVQZ/C) (n = 2-5) and CCSD(T)/cc-pVTZ (n = 6) levels, reveal that the topology of the most stable isomer vary with n and the charge. Out of 674 harmonic frequencies, those with maximum intensity are generally in the 3000-3500 cm-1 range. Analysis of 169 vertical transition energies calculated with the EOM-CCSD approach, suggest three C6H2 species as potential carriers of the diffuse interstellar bands (DIB). Systematic comparison of properties between neutral and cationic species can assist in the structural description of complex matrices.

Investigation into the variation characteristics and influencing factors of coalbed methane gas content in deep coal seams

Gas saturation is a critical parameter for the selection and development of coalbed methane, as well as a key indicator reflecting the challenges in coalbed methane development and productivity evaluation of coalbed methane wells. As one of the significant factors influencing gas saturation, gas content plays a vital role in comprehensively investigating coal pore properties to fully comprehend the process and conditions of methane adsorption and desorption. In this study, 3# and 15# coals from Qinshui Basin, China was selected as research subjects. The experimental evaluation encompassed an examination of composition, pore characteristics, permeability characteristics of coal, rock mechanical parameters while discussing the impact of temperature and pressure on coal's adsorption and desorption capacity. The mineral characteristics analysis revealed that vitrinite is the main component with varying percentages and reflectance values in both 3# and 15# coal seams. The gas content and methane concentration in the 15# coal seam are higher than those in the 3# coal seam. The relationship between gas content within a coal seam and burial depth depends on achieving a balance between positive pressure effects caused by overburden stress exertion on gases trapped within pores under high pressures during burial history versus negative temperature effects due to cooling during geological processes over time. Predictions were made regarding deep-coal gas content which holds significant implications for accurately understanding variations in desorption behavior along with optimizing fracturing engineering.

Methane Adsorption and Desorption on Continental Shaly Matrix: Implications for Shale Gas Condensate Exploration and Production.

Shale gas condensate is a burgeoning unconventional resource with adsorbed methane (CH4) as its dominant component. Successful evaluation of marine shale gas gives limited insights into the evaluation of continental shale gas condensate due to their different occurrence patterns of organic matter and inorganic minerals and resultant contributions to pore development and CH4 ad-/desorption capability. To address this issue, we employed an advanced low-temperature oxygen plasma (LTOP) technology to extract organic matter from the continental shaly matrix. Results showed that the continental shaly matrix contains more clay minerals and less quartz, and develops fewer pores and fractures than typical marine shaly matrix. The organic matter-hosted pores instead of inorganic mineral-hosted pores are more weighted to the pore development in the continental shaly matrix. However, the inorganic minerals of the continental shaly matrix contribute more to CH4 adsorption capability than the organic matter, which could be attributed to the higher density of available adsorption sites toward CH4. Besides, the CH4 ad-/desorption hysteresis is more pronounced for the organic matter-free continental shaly matrix than the raw continental shaly matrix, which is attributed to the remarkable CH4 adsorption-induced clay mineral swelling. Overall, the effects of inorganic minerals in CH4 adsorption and desorption, particularly clay minerals, are crucial for continental shale gas condensate exploration and production.

Effect of Surfactant Modification on Coalbed Methane Desorption and Its Behavioral Mechanism

Effect of Surfactant Modification on Coalbed Methane Desorption and Its Behavioral Mechanism

Study on size effect and model optimization of methane desorption-diffusion in high rank coal

ABSTRACT Methane diffusion models are numerous, but their application, pros, and cons need to be summarized urgently, the link between particle size and methane desorption-diffusion is uncertain. Therefore, this paper carries out the methane desorption-diffusion experiments under multi-scale pressure and particle size conditions to study the effect of coal sample particle size on methane desorption-diffusion. Based on MATLAB, different diffusion models were fitted and comparatively analyzed, and the models were improved in view of their deficiencies. The results showed that the cumulative methane desorption amount and rate are inversely related to the particle size of coal. Comparative analysis of the models revealed that diffusion model under the third type of boundary conditions has a low fitting accuracy for full process of methane desorption, whereas it has a high fitting accuracy of 0.9831 for the first 1000 s of desorption data. Unipore diffusion model, bidisperse diffusion model and new model of dynamic diffusion coefficient have high fitting accuracy for the desorption data of high homogeneous coal, reaching above 0.97, but unipore diffusion model has only 0.5434 fitting accuracy for non-homogeneous coal samples. The fitting accuracy of improved classical unipore diffusion model for both homogeneous and non-homogeneous coals reaches 0.99, which is more extensive than that of unipore diffusion model, only take the first term can satisfy the accuracy requirement, so it is more convenient in the practical engineering application, and has certain reference significance for engineering calculations of gas content and prediction of gas protrusion.

Subsidence associated with dewatering and gas extraction from coal seams: Contribution of desorption-induced coal shrinkage

Several coal seams are contained within the formations of Great Artesian Basin (GAB), the largest natural underground water reservoir in Australia and the world. The extraction of coal seam gas (CSG) and its associated water from thousands of wells within the coal measures of the GAB has led to tens of millimetres of subsidence in CSG development areas. Since highly developed farming systems located in these areas rely on very low slope landforms, even this scale of subsidence has caused significant community concern about the potential for CSG extraction to impair farming operations and productivity through changes in land slope and drainage. Coal seam compaction associated with dewatering and gas extraction has two key components: poromechanical compaction and desorption-induced bulk shrinkage. The former results from pore pressure depletion (due to dewatering and gas extraction) and an increase of vertical effective stress, while the latter is induced by gas desorption from the coal matrix, leading to further deformation. While poromechanical compaction of fluid-bearing formations has been extensively addressed in the literature, relatively little research has been conducted on the role of coal shrinkage in CSG-induced subsidence. This paper introduces an innovative practical modelling approach for assessing CSG-induced subsidence at a subregional/regional scale. The approach utilises an analytical model for CSG-induced subsidence derived from constitutive stress–strain relations for poroelastic-sorptive media. This is a novel approach in the context of CSG-induced subsidence which considers both poromechanical compaction and desorption-induced shrinkage. A further distinction to previous work is the integration of the geomechanical-sorptive subsidence model with a numerical groundwater model. Based on this approach, this paper examines the effect of coal shrinkage on subsidence, and its proportions with respect to total compaction for one of the major coal measures in the Surat Basin. Input data are derived from three-dimensional geological, geomechanical, and groundwater models, as well as methane adsorption and desorption reports. Results show that (a) the impact of coal shrinkage on CSG-induced subsidence is likely to be significant in the study area and (b) the contribution of coal shrinkage to CSG-induced subsidence depends on gas content, Langmuir isotherm, shrinkage strain parameters, and the saturation state of coal. This study provides important insights into CSG-induced subsidence and lays the foundation for the development of robust, efficient, and localised predictive models to support environmental impact assessment and management.

Study on the Wettability and Methane Desorption Characteristics of Coal under High Pressure with Different Surfactants.

In the process of coalbed methane extraction, due to the strong hydrophilicity of coal, the surface interaction force between water and the coal matrix is strong. The hydrophobic effect of the coal seam during drainage and pressure reduction is not significant, and adsorbed methane is difficult to desorb. In order to reduce the surface interaction force promoting methane desorption between water and coal, the surfactants NH766, G526, and D001 with a concentration of 0.1% were selected. A pressure of 12 MPa, which is close to that used for the on-site mining of coalbed methane in Baode, was selected as the experimental condition to simulate hydraulic fracturing of high fat coal, and the influence of different surfactants on methane desorption characteristics was analyzed. Combining contact angle experiments and infrared spectroscopy experiments, we explored the changes in wettability of the coal samples. We compared the changes in wettability and methane desorption characteristics and explored the similarities between these changes. The experimental results showed that after NH766 treatment, the content of oxygen-containing functional groups in coal rock decreased by 30%, and the contact angle of the coal matrix surface increased by 10°. Furthermore, its hydrophobicity was enhanced, and the desorption amount increased by 24%. In contrast, the oxygen-containing functional groups in coal rock after G526 and D001 treatments increased by 5% and 16%, respectively, and the contact angle of the coal matrix surface became smaller. Furthermore, its hydrophilicity was enhanced, and the desorption amount was reduced by 12.5% and 20%, respectively. NH766 reduces wettability and promotes methane desorption, and it can be applied to improve CBM extraction efficiency. G526 and D001 enhance wettability and inhibit methane desorption, which make them suitable for dust prevention and gas control in coal mines.

Modeling microwave heating for enhanced shale gas recovery: Fully coupled two-phase flows with heat transfer and electromagnetism in deformable reservoirs

To investigate the mechanisms of fluid migration during shale gas extraction under microwave irradiation, we developed a coupled Electromagnetic-Thermal-Hydraulic-Mechanical (ETHM) model. This model accounts for changes in fracture permeability due to variations in temperature, gas pressure, and methane desorption. The impact of microwave power on both gas production and the alteration of reservoir geological properties under microwave stimulation was investigated. Simulation results revealed that with a microwave injection power of 4,000 W, cumulative gas production increased by 45 %, reaching 64.9 million cubic meters. Additionally, the influence of initial water saturation and the diffusion damping coefficient on both gas and water production was examined. The findings show that cumulative water production was 33 % higher when microwave heating was applied compared to scenarios without microwave stimulation. An increase in initial water saturation led to a decrease in daily gas production during the early stages of extraction. Under microwave irradiation, the methane adsorption capacity at data acquisition point MP2 decreased to 0.0075 m3/kg, representing a 69 % reduction compared to conditions without microwave stimulation. Our analysis also found that daily gas production is highly sensitive to the diffusion damping coefficient. The diffusion attenuation effect had a notably negative impact on improving the recovery rate of shale gas reservoirs. In a word, this research holds significant implications for understanding the trends in gas and water production as well as the sensitivity of geological parameters during microwave-assisted thermal recovery of shale gas.

Numerical Analysis of Permeability Rebound and Recovery during Coalbed Methane Extraction and Its Implications for Enhanced Coalbed Methane Extraction through Injection of Superheated Water.

Permeability rebound and recovery are pivotal in determining the efficacy of coalbed methane (CBM) extraction and the impact of superheated water injection during thermally enhanced CBM extraction. Existing research predominantly focuses on the roles of effective stress and methane desorption shrinkage, often neglecting the critical influence of the temperature. Therefore, our study introduces a mathematical model incorporating heat-fluid-solid coupling and a permeability evolution model considering temperature variations. The model was used to analyze the phenomenon of permeability rebound and recovery during CBM extraction and the effects of various factors on it. The results show that the permeability rebound and recovery time increase with initial gas pressure but decrease with initial diffusion coefficient and permeability. Initial coal seam temperature has little effect on the permeability rebound time, which increases the recovery time. The permeability rebound value rises with the initial diffusion coefficient but falls with the initial gas pressure and permeability, and the coal seam temperature has little impact on it. In addition, whether to consider the temperature on the permeability evolution is compared. The results reveal that temperature impact causes an elevation in permeability rebound, prolongs rebound and recovery time, and reduces postrecovery permeability ratio compared to the scenario without temperature influence. Inspired by the law of permeability evolution, this paper discusses the impact of injection pressure and temperature on the effectiveness of superheated water injection in the initial stage of enhanced CBM recovery engineering practice. The findings offer valuable insights into selecting optimal injection parameters tailored to various coal seams.

Characterization of Coal Particle Methane Desorption and Optimization of Desorption Model Based on Desorption Damage.

In view of the current situation where most studies on gas desorption characteristics are limited to the atmospheric pressure desorption environment, we have independently developed a coal methane desorption instrument to test the nonatmospheric pressure desorption characteristics for coal particle gas beneath the condition of desorption damage. The instrument can arbitrarily adjust the gas pressure in the range of measurement while controlling the instantaneous release of excess gas to keep the desorption environment pressure constant. We measured the methane desorption amount of coal samples with different desorption times within 3 h and calculated the desorption velocity. The results show that the final desorption amount and desorption velocity of gas scale up with the increase of times, and the final desorption amount of coal sample W-01 increases the most, which is 18.5%. With the passage of time, the diffusion coefficient decreases gradually, and the number of desorption times is directly proportional to the diffusion coefficient. Its relative deviation of diffusion coefficient between different desorption times of the same coal sample can reach up to 40%, and the desorption time in the range of 5 to 30 min is the area with high relative deviation. A quantitative index Ki of a double-parameter damage model based on desorption conditions and adsorption pressure is proposed, and the damage extent of each sample is evaluated. The damage quantitative index of coal sample W-01 is the highest, which is 0.87. The methane desorption model of coal under the condition of desorption damage is constructed, and more than 30 groups of experiments are verified.

Microwave irradiation-induced alterations in physicochemical properties and methane adsorption capability of coals: An experimental study using carbon molecular sieve

In order to comprehend the applicability of microwave irradiation for recovering coalbed methane, it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of metamorphism. In this work, the carbon molecular sieve combined with KMnO4 oxidation was selected to fabricate carbon molecular sieve with diverse oxidation degrees, which can serve as model substances toward coals. Afterwards, the microwave irradiation dependences of pores, functional groups, and high-pressure methane adsorption characteristics of model substances were studied. The results indicated that microwave irradiation causes rearrangement of oxygen-containing functional groups, which could block the micropores with a size of 0.40–0.60 nm in carbon molecular sieve; meanwhile, naphthalene and phenanthrene generated by macro-molecular structure pyrolysis due to microwave irradiation could block the micropores with a size of 0.70–0.90 nm. These alterations in micropore structure weaken the saturated methane adsorption capacity of oxidized carbon molecular sieve by 2.91%–23.28%, suggesting that microwave irradiation could promote methane desorption. Moreover, the increased mesopores found for oxidized carbon molecular sieve after microwave irradiation could benefit CH4 diffusion. In summary, the oxidized carbon molecular sieve can act as model substances toward coals with different ranks. Additionally, microwave irradiation is a promising technology to enhance coalbed methane recovery.

Mechanism of desorption hysteresis in coalbed methane: Insights from microscopic pore properties and adsorption theory

Desorption hysteresis, a phenomenon frequently observed in coal–methane desorption experiments, holds significant implications for coalbed methane extraction due to its influence on the volume of methane involved in migration. Yet, the precise mechanism behind desorption hysteresis remains incompletely understood. This study endeavors to elucidate the underlying mechanism of desorption hysteresis by considering pore characteristics and applying adsorption theory. The pore morphology was assessed using the physisorption method, and ad/desorption isotherms were measured using high-pressure volumetric methods, with the desorption hysteresis index (DHI) utilized to quantify the degree of hysteresis. The results pointed to the pivotal role of micropores (<1.5 nm) in the occurrence of desorption hysteresis. Enhanced specific surface area and pore volume, in conjunction with a decrease in the fractal dimension Ds of micropores, were found to correspond to higher DHI values. Conversely, an increase in meso/macropores (>1.5 nm) corresponded to reduced DHI. The Frenkel–Halsey–Hill fractal dimension showed no substantial correlation with DHI. In light of these findings, it is concluded that micropores, acting as gas entrapment spaces, primarily govern desorption hysteresis, while meso/macropores serve as migration pathways with lesser influence. Micropores exhibit robust adsorption capacity, leading methane molecules to preferentially occupy these spaces. However, during desorption, insufficient potential energy impedes the release of methane molecules from the coal surface, causing desorption hysteresis. These insights offer a fresh perspective on understanding the mechanism of desorption hysteresis in coal, which may prove valuable in optimizing methane extraction.

Estimating the Heat of Methane Desorption from Coal by Means of the Temperature Change

Estimating the Heat of Methane Desorption from Coal by Means of the Temperature Change

Thermodynamic Characteristics of Methane Adsorption and Desorption on Varied Rank Coals: A Systematic Study

Thermodynamic Characteristics of Methane Adsorption and Desorption on Varied Rank Coals: A Systematic Study

A Study on the Production Simulation of Coal–Shale Interbedded Coal Measure Superimposed Gas Reservoirs under Different Drainage Methods

To study the influence of different drainage methods on the production performance of coal measure gas wells, the interbedded reservoir composed of coal and shale in the Longtan Formation of the Dahebian block was used as the research object. Considering the influence of coal and shale matrix shrinkage, effective stress, and interlayer fluid flow on reservoir properties such as fluid migration behavior and permeability, a fluid–solid coupling mathematical model of coal measure superimposed gas reservoirs was established. Numerical simulations of coal measure gas production under different drainage and production modes were conducted to analyze the evolution of reservoir pressure, gas content in the matrix, permeability, and other characteristic parameters of the superimposed reservoir, as well as differences in interlayer flow. The results showed that, compared to single-layer drainage, cumulative gas production increased by 33% under multi-layer drainage. Both drainage methods involve interlayer energy and substance transfer. Due to the influence of permeability, porosity, and mechanical properties, significant differences exist in reservoir pressure distribution, preferential flow direction, gas content in the matrix, and permeability ratio between coal and shale reservoirs under different drainage and production modes. Multi-layer drainage effectively alleviates the influence of vertical reservoir pressure differences between reservoir layers, facilitates reservoir pressure transmission in shale reservoirs, enhances methane desorption in shale matrices, promotes matrix shrinkage, and induces the rebound of shale reservoir permeability, thus improving overall gas production.

Hydrogeological Challenge for Coal Bed Methane (CBM) Production in Structurally Complex Reservoirs: Case Study for the Synclines of Umbita and Checua-Lenguazaque, Colombia

Colombia is advancing toward pilot production of coal bed methane (CBM) at the Umbita syncline (US) and Checua-Lenguazaque syncline (CLS) in the Cundiboyacense plateau of the Eastern Cordillera. Although attractive, the development of CBM resources remains hydrogeologically challenging due to infinite acting aquifer (IAA) conditions, a sustainable production of ineffective water, which removal is critical to achieve methane desorption. Here, we assessed the implications of IAA on methane production prior to pilot development by comparing single-phase flow numerical simulations of the prospects. The results suggest IAA would extend the dewatering period in the Umbita syncline up to 20 years to potentially compromise the commercial recovery of methane. The Chequa-Lenguasaque, on the other hand, appears to have reached the phase of production of effective water; therefore, it is deemed as the most attractive prospect for pilot testing the production of CBM in Colombia.