A Comprehensive Appraisal on the Characteristics of Coal-Bed Methane Reservoir in Turpan-Hami Basin

The rich coal-bed methane resources in the Turpan-Hami Basin are mainly located in the Shisanjianfang,Hami,Shanshan,Sha'erhu,Kekeya,Kerjian,Aidinghu inclines and the Dananhu coal-bed methane reservoirs. The big-ger coal-bed reservoirs are sitting at a depth of less than 1500 m. The coalbed methane generation,storage and confin-ing conditions of the Turpan-Hami basin can be indicated by eight key parameters. They are coal-bed thickness,coal rank,missing period,permeability,Langmuir volume,rock covering ability,structural confinement and hydrodynamic sealing environment. These parameters constitute a comprehensive appraisal index system of the coal-bed methane res-ervoir characteristics of the Turpan-Hami basin. In these parameters,the missing period of coal-bed methane is indi-cated by a stratum missing intensity factor. It reflects the relative exposure period of coal series. The results of a fuzzy comprehensive judgment showed that the Shisanjianfang coal-bed methane reservoir has the best prospects for exploita-tion and the Sha'erhu,Shanshan,Hami coal-bed methane reservoirs are next in line.

Application of Seismic Anisotropy Caused by Fissures in Coal Seams to the Detection of Coal-bed Methane Reservoirs

Coal-bed methane is accumulated in micro-fissures and cracks in coal seams. The coal seam is the source terrace and reservoir bed of the coal-bed methane (Qian et al., 1996). Anisotropy of coal seams is caused by the existence of fissures. Based on the theory of S wave splitting: an S wave will be divided into two S waves with nearly orthogonal polarization directions when passing through anisotropic media, i.e. the fast S wave with its direction of propagation parallel to that of the fissure and slow S wave with the direction of propagation perpendicular to that of the fissure.

A Pilot-scale Demonstration of Reverse Osmosis Unit for Treatment of Coal-bed Methane Co-produced Water and Its Modeling

This study presents the first demonstration project in China for treatment of coal-bed methane(CBM) co-produced water and recycling.The work aims to provide a research and innovation base for solving the pollution problem of CBM extraction water.The reverse osmosis(RO) unit is applied to the treatment of CBM co-produced water.The results indicate that system operation is stable,the removal efficiency of the total dissolved solids(TDS) is as high as 97.98%,and Fe,Mn,and F-are almost completely removed.There is no suspended solids(SS) detected in the treated water.Furthermore,a model for the RO membrane separation process is developed to describe the quantitative relationship between key physical quantities-membrane length,flow velocity,salt concentration,driving pressure and water recovery rate,and the water recovery restriction equation based on mass balance is developed.This model provides a theoretical support for the RO system design and optimization.The TDS in the CBM co-produced water are removed to meet the "drinking water standards" and "groundwater quality standards" of China and can be used as drinking water,irrigation water,and livestock watering.In addition,the cost for treatment of CBM co-produced water is assessed,and the RO technology is an efficient and cost-effective treatment method to remove pollutants.

Coal-Bed Methane Resource of Mesozoic Basins in Jiamusi Landmass

As a new-replacement of energy resource, coal bed methane is the important gas resource with great strategic significance. There are several number of Mesozoic coal-bearing basins in Jiamusi landmass, eastern Heilongjiang Province. Theresult of the resource assessment revealed that the total resource less than 1 500 m,s depth in the area is about 2 100×108m3. It shows that Jiamusi landmass has great potential of coal-bed gas and is one of the most prospecting districts for developing coal-bed gas in CBM-province Northeast China.

The experiment study on slippage effect of the coal-bed methane transfusion

When the gas flow in the compact porous medium at low speed,it has slippage effect which is caused by the gas molecular collision whit the solidskeleton.Using the gas transfusion slippage effect at researching the coal bed transfusion rule,established the transfusion mathematical model of the coal bed which had considered the slippage effect. Observing the influence of the different toencircle presses,the different hole press and the different actual stress to the coal bed by using the three-axles permeameter.Thus sum- marized the transfusion rule of the coal bed.The experiment indicates that the bigger of the surrounding pressure,the more obvious of the slippage effect.At the same condition of axial pressure and the surrounding pressure,with the increase of the hole pressure,the coal permeability became bigger and then smaller.The coal body effective tress and the permeability curve nearly also has the same change tendency.Thus we can draws the conclusion that the transfusion of the gas in the coal bed generally has the slippage effect.

Research regarding coal-bed wellbore stability based on a discrete element model

Wellbore instability is a key problem restricting efficient production of coal-bed methane. In order to perform thorough and systematic research regarding coal-bed wellbore stability problems, a new discrete element model which fully considers the features of cleat coal-beds is established based on the Kirsch equation. With this model, the safe pipe tripping speed, drilling fluid density window and coal- bed collapse/fracture pressure are determined; in addition, the relationships between pipe tripping speed and pipe size, cleat size, etc. and wellbore stability are analyzed in the coal-bed drilling and pipe tripping processes. The case studies show the following results： the wellbore collapses （collapse pressure： 4.33 MPa） or fractures （fracture pressure： 12.7 MPa） in certain directions as a result of swab or surge pressure when the pipe tripping speed is higher than a certain value; the cleat face size has a great influence on wellbore stability, and if the drilling fluid pressure is too low, the wellbore is prone to collapse when the ratio of the face cleat size to butt cleat size is reduced; however, if the drilling fluid pressure is high enough, the butt cleat size has no influence on the wellbore fracture; the factors influencing coal-bed stability include the movement length, pipe size, borehole size.

Dual polarization strategy to enhance CH_(4) uptake in covalent organic frameworks for coal-bed methane purification

The purification of low-grade coal-bed methane is extremely important,but challenging,due to the very similar physical properties of CH_(4)and N2.Herein,we proposed a dual polarization strategy by employing triazine and polyfluoride sites to construct polar pores in COF materials,achieving the efficient separa-tion of CH_(4)from N2.As expected,the dual polarized F-CTF-1 and F-CTF-2 exhibit higher CH_(4)adsorption capacity and CH_(4)/N_(2)selectivity than CTF-1 and CTF-2,respectively.Especially,the CH4 uptake capacity and CH_(4)/N_(2)selectivity of F-CTF-2 is 1.76 and 1.42 times than that of CTF-2.This work not only developed promising COF materials for CH4/N_(2)separation,but also provided important guidance for the separation of other adsorbates with similar properties.

Effects of micropore structure of activated carbons on the CH_(4)/N_(2) adsorption separation and the enrichment of coal-bed methane

In the process of enriching CH4 from coal-bed methane,the separation of CH_(4)/N_(2)is very difficult to accomplish by an adsorption process due to the similar physico-chemical properties of the two molecules.A series of coconut-shell-based granular activated carbons(GACs)with different pore structures were prepared,which were characterized by different methods.The influence of the pore structure on the separation properties was investigated in detail.The results show that one of the carbons prepared(GAC-3)has high CH4 equilibrium adsorption capacity(3.28 mol·kg–1)at 298 K and equilibrium separation coefficient(3.95).The CH_(4)/N_(2)separation on the GACs is controlled by adsorption equilibrium as compared with the dynamic effect.Taking the specific surface area,for example,the common characterization index of the pore structure is not enough to judge the separation performance of the GACs.However,the microstructure of carbon materials plays a decisive role for CH_(4)/N_(2)separation.According to the pore-structure analysis,the effective pore size for the CH_(4)/N_(2)separation is from 0.4 to 0.9 nm,with the optimum effect occurring in the range of 0.6–0.7 nm,followed by the range of 0.7~0.9 nm.Also,a four-bed vacuum pressure swing adsorption process was adopted to evaluate the performance of GACs for the separation of CH4 from nitrogen.

中国油气行业甲烷排放估算与减排分析

甲烷是仅次于二氧化碳的第二大温室气体,据统计全球甲烷排放中石油天然气行业排放占比高达三分之一,加强甲烷排放管控对推动“双碳”目标的实现具有重要的意义。为此,结合油气消费量预期、行业控排预期等,估算了2021—2060年中国油气行业甲烷排放量;并进一步分析了减排目标下技术减排潜力和减排成本,最后结合各类排放源占比及现有减排技术的成本效益,测算了2030年与2060年2个时间节点油气行业甲烷减排的边际成本。研究结果表明:①2021—2060年期间,油气行业甲烷排放量略有下降,天然气系统甲烷排放量增速变缓,其中运输和输配环节有较大减排潜力;②油气行业90%的甲烷排放量集中在30%的排放源中,有10%~20%的甲烷无法彻底通过技术减排;③在2030年、2060年实施的减排技术中,具有收益的技术比例分别达22.0%和44.4%;④2030、2060年的甲烷平均单位减排成本分别为22.33元/m^(3)和14.57元/m^(3)。结论认为,中国油气行业在中长期需要加快推进甲烷排放检测、报告、核查体系的建设,推动排放数据的精细化,并通过绿色金融、中国碳减排核证方法学开发等多种方式,持续提升行业甲烷减排积极性。

中国煤层气产业系统动态预测及政策模拟研究

煤层气产业为复杂社会经济系统,通过系统分析确定了煤层气产业的社会经济、市场、政策、资源环境及煤层气产业五个子系统,在此基础上建立中国煤层气产业系统动力学模型。分析了模型的合理性,并对社会经济环境变化、国家政策的变化、投资方式的变化、国家能源市场控制的变化等几个主要方面进行预测分析,并对降低单位国民经济产值能耗的变化、改变煤层气定价方式、调整国家煤层气价格补贴等方面提出政策建议。结果表明该模型设计较为合理,能够较为系统的模拟煤层气产业发展中的基本状况,对于预测煤层气产业的动态预测及政策建议有意义。

天然气助力未来世界发展--第27届世界天然气大会(WGC)综述

以天然气为代表的低碳清洁能源是当前世界能源行业关注的热点。第27届世界天然气大会(WGC)于2018年6月25—29日在美国首都华盛顿召开,本次会议对过去3年世界天然气业务的发展进行了系统回顾、展望了发展前景,并达成了以下共识:(1)天然气是低碳、清洁、绿色、多元的"三可"(可靠的、可承受的、可持续的)能源;(2)全球天然气产业快速发展,市场呈现出相对宽松的态势;(3) LNG是目前世界天然气发展的重点;(4)甲烷泄漏与排放已成为公众关注的焦点;(5)天然气的灵活性、碳捕集封存技术和碳排放定价机制成为天然气与可再生能源组成"互补搭档"的推手;(6)提高天然气自给度是平抑区域性价格差异和决定定价话语权的有力手段;(7)争取政府对天然气产业的支持,重视公众的关注和参与。基于在本次大会上所取得的认识与收获,对中国天然气业务下一步的发展提出了如下建议:(1)进一步加大对国内常规和非常规天然气的勘探开发力度;(2)重点补齐工程技术等制约天然气业务发展的关键核心技术短板;(3)统筹考虑天然气上下游业务;(4)加强全业务链甲烷泄漏管控;(5)统筹制定天然气进口贸易对策。

我国煤层气资源开发利用的财政政策评析

煤层气主要成分与天然气相同,是优质的清洁能源。煤层气资源开发的经济效益无法与天然气开发相比拟,但具有较大的社会效益和环境效益。目前,我国政府十分关注煤层气资源的开发利用,出台了一系列煤层气资源开发利用的财政优惠政策。本文结合山西沁水盆地煤层气资源开发的实际情况,分析了我国现行煤层气资源开发利用财政政策的利弊之处,提出了鼓励我国煤层气产业发展的相关财税政策建议。

我国煤制天然气产业动态、存在问题及建议

介绍了我国天然气供需状况和煤制天然气产业的发展现状,分析了煤制天然气工艺相关核心技术及整体工艺特点,认为煤制天然气工艺技术相对成熟。在煤制天然气产业化发展过程中,应考虑解决管网准入、调峰、定价机制、碳税等问题,并提出了一些国家层面上需统筹考虑的合理化建议。

低油价下国内非常规气与进口气竞争力对比

近年来,非常规天然气已成为我国天然气供应的重要构成之一,在低油价的新常态下,中国油气行业面临究竟是继续低效益开发国内非常规气,还是加大进口海外天然气的现实抉择。为此,基于国内典型非常规气田的开发成本现状,采用净现金流量法,开展了典型非常规气田单井经济效益评价,构建了反映单井投资、累计产量、内部收益率3大关键指标的技术经济界限图版并与进口气价格进行对比,得出不同油价下我国非常规气效益开发的最优序列。研究结果表明:(1)在当前气价、投资、产量水平下,只有致密气藏"甜点区"可实现效益开发,煤层气藏、页岩气藏的内部收益率均低于基准收益率,有待于进一步降本增效;(2)当原油价格发生变化时,若油价为40美元/桶(1桶=0.159 m^3),国产致密气相比进口LNG效益更优,可优先开发,并加大LNG进口比例;(3)若油价为50美元/桶及以上时,国产非常规气相比进口LNG效益更优,应加大开发力度,平衡好国产气与进口气的供应比例关系,以实现效益最大化。

基于环境成本的煤层气价格竞争力研究

以我国煤层气产业发展为背景,分析了我国煤层气价格竞争力的现状及影响因素,得出能源经济成本的逐步下降是提高价格竞争力的根本,在能源经济成本既定的条件下,环境成本是能源价格竞争力的关键。通过对比煤层气发电和燃煤发电成本,测算出煤层气的价格竞争力。实证分析结果显示:在不考虑环境成本的条件下,我国煤层气发电的成本约为0.3元/千瓦时~0.6元/千瓦时,高于火力发电的0.325元/千瓦时,表明煤层气缺乏价格竞争力。如果把煤层气和火力发电所产生的环境成本货币化,煤层气发电将具备一定的价格竞争力。根据以上研究结果提出逐步落实煤层气定价机制,不断调整价格补贴政策,提高煤层气价格竞争力,促进煤层气产业发展。

Geothermal field and its relation with coalbed methane distribution of the Qinshui Basin

The average geothermal gradient in the Qin-shui Basin, Shanxi Province, North China, estimated from temperature logging data of 20 boreholes is 28.2±1.03℃/km. The thermal conductivities of 39 rock samples are measured and 20 heat flow values are obtained. The estimated heat flow ranges from 44.75 mW7m2 to 101.81 mW/m2, with a mean of 62.69±15.20 mW/m2. The thermal history reconstruction from the inversion of vitrinite data, using Ther-model for Windows 2004, reveals that the average paleo-heat flow at the time of maximum burial in late Jurassic to early Cretaceous is 158.41 mW/m2 for the north part, 119.57 mW/m2 for the central part and 169.43 mW/m2for the south part of the basin respectively. The reconstruction of the buried history of the strata indicates that the age for the end of sedimentation and the beginning of erosion for the basin is 108-156 Ma, and that the eroded thickness of the strata is 2603 m in the north, 2291 m in the central, and 2528.9 m in the south of the basin respectively. The 'higher in the north and the south, lower in the central' distribution pattern of the paleo-heat flow coincides with the distribution of the coal-bed methane spatially and temporally, which shows that the coal-bed methane is controlled by the paleo-geotem-perature field in the basin.

“Exploring petroleum inside source kitchen”: Connotation and prospects of source rock oil and gas

Based on the transitional background of the global energy structure, exploration and development of unconventional oil and gas, and investigation of key basins, the unconventional oil and gas resources are divided into three types: source rock oil and gas, tight oil and gas, and retention and accumulated oil and gas. Source rock oil and gas resources are the global strategic supplies of oil and gas, the key resource components in the second 150-year life cycle of the future petroleum industry, and the primary targets for "exploring petroleum inside source kitchen". The geological connotation of source rock oil and gas was proposed, and the models of source rock oil and gas generation, expulsion and accumulation were built, and five source rock oil and gas generation sections were identified, which may determine the actual resource potential under available technical conditions. The formation mechanism of the "sweet sections" was investigated, that is, shale oil is mainly accumulated in the shale section that is close to the oil generation section and has higher porosity and permeability, while the "sweet sections" of coal-bed methane(CBM) and shale gas have self-contained source and reservoir and they are absorbed in coal seams or retained in the organic-rich black shale section, so evaluation and selection of good "sweet areas(sections)" is the key to "exploring petroleum inside source kitchen". Source rock oil and gas resources have a great potential and will experience a substantial growth for over ten world-class large "coexistence basins" of conventional-unconventional oil and gas in the future following North America, and also will be the primary contributor to oil stable development and the growth point of natural gas production in China, with expected contribution of 15% and 30% to oil and gas, respectively, in 2030. Challenges in source rock oil and gas development should be paid more attention to, theoretical innovation is strongly recommended, and a development pilot zone can be established to strengthen technology and promote national support. The source rock oil and gas geology is the latest progress of the "source control theory" at the stage of unconventional oil and gas. It will provide a new theoretical basis for the new journey of the upstream business in the post-industry age.

煤制天然气产业发展前景分析

我国天然气供不应求的局面将长期存在,而利用煤炭资源相对丰富的特点发展煤制天然气产业,是缓解我国天然气供求矛盾的一条有效途径。煤制天然气产品的低热值比国家天然气质量标准规定的低热值高17.8%～21%,能量转化效率高。当石油价格为80美元/bbl时,与进口天然气、进口LNG相比,煤制天然气价格具有竞争力。固定床鲁奇炉加压气化技术是煤制天然气较好的选择,而耐硫变换、低温甲醇洗、硫回收、丙烯制冷、压缩干燥等工艺单元不存在技术问题。如果我国企业开发的低温甲烷化技术获得成功,那么煤制天然气项目就可以完全实现国产化,使我国煤制天然气技术居于世界前列。利用低品质的褐煤、采用碎煤固定床鲁奇炉加压气化技术,粗煤气中含有8%～12%的甲烷,气化单元投资仅为气流床气化技术的一半,电耗低,同时可实现焦油、轻油、酚、硫磺、硫酸铵等多联产。但对于排出的"黑水"问题,应采取积极措施尽快予以解决。煤制天然气项目最好在示范装置取得圆满成果之后,特别是环境保护问题解决之后,再进行项目的研究和建设。厂址最好设在坑口或煤炭产地附近,并且要考虑输送问题。

基于环境成本的煤层气价格与煤炭价格联动机制研究

根据边际效用价格理论,以能源热值为媒介,通过建立价格联动模型进行实证分析,研究煤层气与煤炭的价格联动关系。模型创新点在于考虑环境因素,将环境成本记入能源价值。研究表明:煤层气和煤炭存在价格联动关系,在模型假设条件下,煤炭价格每公斤上涨1元,煤层气价格每立方米上涨1.74元;在相同热值下,煤层气的价格高于煤炭价格,在能源市场上不具备竞争优势。根据以上研究结果提出了改进建议,对于煤层气产业改变现有成本导向型价格机制,形成市场导向型价格机制,促进煤层气产业发展,提高煤层气资源配置效率有积极影响。

Early Opportunity of CO_2 Storage in Coal Bed of China

A study to identify potential early opportunities for CO2 storage in coal bed has been performed. CO2-ECBM can enhances the recovery of coalbed methane,and also store CO2 in coal for geological time.CO2-ECBM is an effective measure for CO2 mitigation,and also enhance the recovery of coalbed methane that can reduce the cost of CO2 geological storage.The evaluation index system of feasibility