As the main unconventional natural gas reservoirs,shale gas reservoirs and coalbed methane(CBM)reservoirs belong to adsorptive gas reservoirs,i.e.,gas reservoirs containing adsorbed gas.Shale gas and CBM reservoirs us...As the main unconventional natural gas reservoirs,shale gas reservoirs and coalbed methane(CBM)reservoirs belong to adsorptive gas reservoirs,i.e.,gas reservoirs containing adsorbed gas.Shale gas and CBM reservoirs usually have the characteristics of rich adsorbed gas and obvious dynamic changes of porosity and permeability.A generalized material balance equation and the corresponding reserve evaluation method considering all the mechanisms for both shale gas reservoirs and CBM reservoirs are necessary.In this work,a generalized material balance equation(GMBE)considering the effects of critical desorption pressure,stress sensitivity,matrix shrinkage,water production,water influx,and solubility of natural gas in water is established.Then,by converting the GMBE to a linear relationship between two parameter groups related with known formation/fluid properties and dynamic performance data,the straight-line reserve evaluation method is proposed.By using the slope and the y-intercept of this straight line,the original adsorbed gas in place(OAGIP),original free gas in place(OFGIP),original dissolved gas in place(ODGIP),and the original gas in place(OGIP)can be quickly calculated.Third,two validation cases for shale gas reservoir and CBM reservoir are conducted using commercial reservoir simulator and the coalbed methane dynamic performance analysis software,respectively.Finally,two field studies in the Fuling shale gas field and the Baode CBM field are presented.Results show that the GMBE and the corresponding straight-line reserve evaluation method are rational,accurate,and effective for both shale gas reservoirs and CBM reservoirs.More detailed information about reserves of shale gas and CBM reservoirs can be clarified,and only the straight-line fitting approach is used to determine all kinds of reserves without iteration,proving that the proposed method has great advantages compared with other current methods.展开更多
借助Fluent软件模拟了甲烷–空气扩散燃烧过程,对燃烧过程进行了熵产分析。单位体积内由导热和对流、粘性耗散、质量扩散和化学反应过程的不可逆性产生的局部熵产率通过用户自定义函数(user defined function,UDF)求解,由辐射过程的不...借助Fluent软件模拟了甲烷–空气扩散燃烧过程,对燃烧过程进行了熵产分析。单位体积内由导热和对流、粘性耗散、质量扩散和化学反应过程的不可逆性产生的局部熵产率通过用户自定义函数(user defined function,UDF)求解,由辐射过程的不可逆性导致的局部熵产率则通过对已求解的温度场进行后处理得到。结果表明对含有辐射换热的传热过程进行热力学分析时,辐射熵产不能忽略。在燃料和空气入口温度及壁面温度不变时,总熵产数随燃料入口雷诺数和玻尔兹曼数的增大分别先减小后增大。因此可以选择适当的燃料入口雷诺数和玻尔兹曼数使系统的总熵产数最小,从而提高能量利用效率。展开更多
针对煤矿乏风瓦斯排放污染环境、浪费资源的问题,开发了一种新型乏风瓦斯催化氧化发电系统。该系统主要由掺混装置、压气机、催化燃烧室、透平以及永磁发电机等组成。通过联机试验运行表明,该套发电系统成功实现了额定发电功率30 k W的...针对煤矿乏风瓦斯排放污染环境、浪费资源的问题,开发了一种新型乏风瓦斯催化氧化发电系统。该系统主要由掺混装置、压气机、催化燃烧室、透平以及永磁发电机等组成。通过联机试验运行表明,该套发电系统成功实现了额定发电功率30 k W的设计指标,既可以处理掉乏风中的甲烷气体,同时还可以生产清洁的电能。展开更多
Various countries have rapidly implemented strict actions to slow the blowout of COVID-19.Many events were dis-regarded,and anthropogenic activities such as industrial and transport systems were at a stoppage.Many cou...Various countries have rapidly implemented strict actions to slow the blowout of COVID-19.Many events were dis-regarded,and anthropogenic activities such as industrial and transport systems were at a stoppage.Many countries were on lockdown,including the largest emitters of carbon dioxide.Due to these lockdowns,anthropogenic activities have been reduced and reported that air quality improves at a regional scale in many countries,including India.Therefore,the current study using Greenhouse Gases Observing Satellite(GOSAT/IBUKI)datasets to monitor the fluctuation of the average global concentration of dry mole fractions of atmospheric Methane(CH_(4))and Carbon Dioxide(CO_(2))during these pandemic lockdowns from January to June 2020.Outputs emphasize no significant reduction in the average concentration of dry mole fractions of atmospheric CH_(4) over the globe,but a minor reduction was observed in global CO_(2) engagement.The average concentration of both gases compares at each ten-degree latitude.The study reveals that,against the regional breakdowns,these short time lockdowns are not enough to control the concentration of these greenhouse gases at a larger scale,such as 10°latitude and globally,except for a minor reduction in CO_(2) concentration.展开更多
基金supported by Science and Technology Major Project of Shanxi Province,China(No.20201101002)Science and Technology Major Project of China,China(No.2016ZX05043002)+1 种基金National Natural Science Foundation Project of China,China(No.51874319)Science Foundation of China University of Petroleum(Beijing),China(No.2462020QNXZ003)to support part of this work
文摘As the main unconventional natural gas reservoirs,shale gas reservoirs and coalbed methane(CBM)reservoirs belong to adsorptive gas reservoirs,i.e.,gas reservoirs containing adsorbed gas.Shale gas and CBM reservoirs usually have the characteristics of rich adsorbed gas and obvious dynamic changes of porosity and permeability.A generalized material balance equation and the corresponding reserve evaluation method considering all the mechanisms for both shale gas reservoirs and CBM reservoirs are necessary.In this work,a generalized material balance equation(GMBE)considering the effects of critical desorption pressure,stress sensitivity,matrix shrinkage,water production,water influx,and solubility of natural gas in water is established.Then,by converting the GMBE to a linear relationship between two parameter groups related with known formation/fluid properties and dynamic performance data,the straight-line reserve evaluation method is proposed.By using the slope and the y-intercept of this straight line,the original adsorbed gas in place(OAGIP),original free gas in place(OFGIP),original dissolved gas in place(ODGIP),and the original gas in place(OGIP)can be quickly calculated.Third,two validation cases for shale gas reservoir and CBM reservoir are conducted using commercial reservoir simulator and the coalbed methane dynamic performance analysis software,respectively.Finally,two field studies in the Fuling shale gas field and the Baode CBM field are presented.Results show that the GMBE and the corresponding straight-line reserve evaluation method are rational,accurate,and effective for both shale gas reservoirs and CBM reservoirs.More detailed information about reserves of shale gas and CBM reservoirs can be clarified,and only the straight-line fitting approach is used to determine all kinds of reserves without iteration,proving that the proposed method has great advantages compared with other current methods.
文摘借助Fluent软件模拟了甲烷–空气扩散燃烧过程,对燃烧过程进行了熵产分析。单位体积内由导热和对流、粘性耗散、质量扩散和化学反应过程的不可逆性产生的局部熵产率通过用户自定义函数(user defined function,UDF)求解,由辐射过程的不可逆性导致的局部熵产率则通过对已求解的温度场进行后处理得到。结果表明对含有辐射换热的传热过程进行热力学分析时,辐射熵产不能忽略。在燃料和空气入口温度及壁面温度不变时,总熵产数随燃料入口雷诺数和玻尔兹曼数的增大分别先减小后增大。因此可以选择适当的燃料入口雷诺数和玻尔兹曼数使系统的总熵产数最小,从而提高能量利用效率。
文摘Various countries have rapidly implemented strict actions to slow the blowout of COVID-19.Many events were dis-regarded,and anthropogenic activities such as industrial and transport systems were at a stoppage.Many countries were on lockdown,including the largest emitters of carbon dioxide.Due to these lockdowns,anthropogenic activities have been reduced and reported that air quality improves at a regional scale in many countries,including India.Therefore,the current study using Greenhouse Gases Observing Satellite(GOSAT/IBUKI)datasets to monitor the fluctuation of the average global concentration of dry mole fractions of atmospheric Methane(CH_(4))and Carbon Dioxide(CO_(2))during these pandemic lockdowns from January to June 2020.Outputs emphasize no significant reduction in the average concentration of dry mole fractions of atmospheric CH_(4) over the globe,but a minor reduction was observed in global CO_(2) engagement.The average concentration of both gases compares at each ten-degree latitude.The study reveals that,against the regional breakdowns,these short time lockdowns are not enough to control the concentration of these greenhouse gases at a larger scale,such as 10°latitude and globally,except for a minor reduction in CO_(2) concentration.
