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1.
在分析淮南矿区煤层气地质背景的基础上,采用含量梯度法、压力—吸附法计算了研究区可采煤层的剩余煤层气资源量,探讨了影响该区煤层气可采潜力的煤储层压力、渗透能力、吸附/解吸特征、含气饱和度、可采系数等因素。结果表明,淮南矿区-1 500m以浅剩余煤层气资源量为2 419.70×108m3,可采资源量为1 102.20×108m3,可采资源丰度为1.98×108m3/km2,属于中等储量丰度的大型气田;区内煤储层为正常压力储层,煤储层渗透率、含气饱和度偏低,但本区可采煤层层数多,在渗透率总体偏低的背景下,区内存在的高渗区,具备煤层气地面开采的基础地质条件。  相似文献   

2.
云南老厂矿区煤层气资源丰富,是近年来我国煤层气资源勘探开发的热点区域。针对煤层厚度、储层物性、含气量等储层基本参数特征进行分析,对区域煤层气资源潜力进行评价。结果表明:云南老厂矿区煤层厚度较大、层数较多,煤层顶底板以泥岩、粉砂岩为主,生储盖配置较好;目标煤层孔隙度相对较高,裂隙较为发育,可为煤层气的富集和产出提供良好的条件;主要煤层压力整体上属于常压储层,煤层解吸速率较高;同时煤储层大多处于欠饱和状态,开发过程中需要较长时间的排水降压;老厂矿区雨汪区块埋藏深度小于1 000 m的煤层气资源量为270.93亿m3,资源丰度为3.20亿m3/km2。总体而言,研究区煤层气勘探开发条件较好,具有较大的勘探开发的资源潜力。  相似文献   

3.
为了提高煤层气井合层排采效果,需要合理划分排采阶段并制定与之对应的管控措施。基于贵州六盘水地区以往煤层气勘查与试采工作,分析该区二叠系龙潭组煤层气地质条件和煤储层特征,对比分析两口煤层气井合层排采管控制度及其效果。结果表明:研究区具有煤层层数多、单层厚度薄、含气量高、储层压力大、煤层渗透率低、局部构造煤发育等煤层气地质特点,使煤层气井排采过程中压敏效应和贾敏效应较明显,储层伤害较严重,煤层气井高产时间较短,产气量较低。应该优选厚度较大、含气性好的原生结构煤层或煤组进行射孔压裂。在合层排采过程中,对排采阶段进行合理划分,并根据排采阶段控制流压、套压、流压降幅、套压降幅和液面高度等参数,可有效减小压敏效应、贾敏效应、速敏效应等储层伤害。合理的合层排采管控有助于实现控制产气量稳定平稳上升、煤层气井长期稳产与高产的目标。   相似文献   

4.
煤层气井多煤层合采效果研究为煤炭安全、井下瓦斯治理、确定开发技术指标、单井配产、合理划分开发层系、煤层气高效开发以及制定中长期煤层气开发规划具有很好的参考价值。以晋城成庄矿区为例,将开发中后期排采效果检验井含气量等数据与邻近井原始含气量进行对比,分析3、9和15煤各煤层含气量在合层排采后的变化特征,以评价排采效果;并结合地质资料及现场排采动态进一步分析影响各煤层排采效果的主控因素。综合分析认为,成庄矿区经过多年地面煤层气多层合采,下部15号煤层比上部3号和9号煤层含气量降低更快。分析其原因认为成庄矿区15号煤层含气量降低较快的主要影响因素包括煤层渗透率、供液能力、储层压力及排采制度等。研究结果为剩余储量预测提供可靠的科学依据。   相似文献   

5.
阜新盆地刘家区煤储层综合分析   总被引:2,自引:0,他引:2  
在对阜新盆地刘家区构造演化及构造特征、煤层发育特征、煤的化学成分及排采试验资料分析的基础上,对研究区煤层气含量、煤的吸附性、煤层渗透率、煤储层压力、临界解吸压力、煤体结构、煤层气产出特点进行了综合研究。认为研究区煤层分布广、厚度大、丰度高,煤的吸附能力强;而且埋深与辉绿岩侵入体是控制煤层气含量的主要因素,成煤后期构造运动是影响煤储层渗透率的关键因素。煤层气开发有利区应在向斜翼部和岩墙、岩床附近煤变质程度高的区域。  相似文献   

6.
珲春盆地煤层气取得工业突破对我国低煤阶含煤盆地的煤层气勘探具有重要意义。通过对珲春盆地低煤阶煤层气成藏条件的深入剖析,探讨了低煤阶煤层气富集的主控因素及其成藏模式。结果表明,珲春盆地具有煤阶低、煤层多、煤层薄的特点,构造作用、沉积特征和岩浆岩侵入是其富集成藏的主控因素。盆地西部的褶皱和断层伴生带不仅为生物气创造有利环境,而且为煤层气二次成藏提供场所,形成"连续褶皱"富气模式;沼泽和天然堤微相的垂向叠置,使得作为煤层直接顶底板的泥岩和致密砂岩对煤层气起到更好的封闭作用;局部辉绿岩侵入体促使煤层再次生气,同时大大改善了煤岩的物性。因此,珲春盆地西部是煤层气高产富集区,具有巨大勘探开发潜力。   相似文献   

7.
芦岭煤矿卸压区瓦斯综合抽采试验及分析   总被引:4,自引:0,他引:4  
煤炭开采造成煤储层卸压,煤储层参数将发生巨大变化,并对瓦斯储存和运移产生极大影响。分析了淮北芦岭煤矿卸压区地面垂直井煤层气抽采试验,研究了卸压区地面和井下瓦斯综合抽采技术及方法。结果显示,在低透气性煤层卸压区进行地面和井下瓦斯综合抽采,不仅有利于煤矿安全生产,而且可大大提高瓦斯采收率及其开发的经济效益。   相似文献   

8.
《China Geology》2020,3(1):38-51
Coal measure gas (also known as coal-bearing unconventional gas) is the key field and development direction of unconventional natural gas in recent years. The exploration and evaluation of coal measure gas (coalbed methane, coal shale gas and coal measure tight sandstone gas) from single coalbed methane has greatly expanded the field and space of resource evaluation, which is of positive significance for realizing the comprehensive utilization of coal resources, maximizing the benefits and promoting the innovation of oil and gas geological theory and technological advances in exploration and development. For the first time, in Yangmeishu Syncline of Western Guizhou Province, the public welfare coalbed methane geological survey project of China Geological Survey has been carried out a systematic geological survey of coal measure gas for the Upper Permian Longtan Formation, identified the geological conditions of coal measure gas and found high quality resources. The total geological resource quantity of coalbed methane and coal shale gas is 51.423×109 m3 and the geological resource abundance is up to 566×109 m3/km2. In this area, the coal measures are characterized by many layers of minable coal seams, large total thickness, thin to the medium thickness of the single layer, good gas-bearing property of coal seams and coal measure mudstone and sandstone, good reservoir physical property and high-pressure coefficient. According to the principle of combination of high quality and similarity of key parameters of the coal reservoir, the most favorable intervals are No.5−2, No.7 and No.13−2 coal seam in Well YMC1. And the pilot tests are carried out on coal seams and roof silty mudstone, such as staged perforation, increasing hydraulic fracturing scale and “three gas” production. The high and stable industrial gas flow with a daily gas output of more than 4000 m3 has been obtained, which has realized the breakthrough in the geological survey of coal measure gas in Southwest China. Based on the above investigation results, the geological characteristics of coal measure gas in the multi-thin-coal-seam-developed area and the co-exploration and co-production methods, such as the optimization method of favorable intervals, the high-efficiency fracturing and reservoir reconstruction method of coal measures, and the “three gas” drainage and production system, are systematically summarized in this paper. It will provide a reference for efficient exploration and development of coal measure gas in similar geological conditions in China.  相似文献   

9.
煤矿区煤层气开发受煤矿采动影响,为实现煤矿采动条件下煤层气井产能数值模拟,抽象概化了采动条件下煤层气开发的地质模型,构建了采动条件下煤层气储层的数学模型,并通过对CBM-SIM软件二次开发,实现了采动条件下煤层气储层的数值模拟。在建模和数值解算软件开发中,基于采动离层量变化曲线公式构建了采动条件下储层渗透率变化曲线公式,利用采动井水位变化规律构建了储层漏失水量变化公式,利用时间卡机制解决了煤储层渗透率及漏失水量的动态求解和循环迭代过程中作为系数和边界条件的调用赋值,实现了渗透率随采动影响的动态变化、储层水漏失降压和储层产气的耦合解算。应用开发的软件对淮南矿区某矿采动条件下煤层气抽采井生产数据进行历史拟合和产量模拟应用,预测煤层气产量曲线与实际生产曲线基本一致,判定系数达到0.92。   相似文献   

10.
Thirteen coal areas of the Maritime Provinces in Atlantic Canada are estimated to contain some 2.23 trillion m3 (78.8 TCF) [TCF, BCF, MCF: trillion, billion, million cubic feet]) of coalbed methane resources. This compares with 510 billion m3 (18 TCF) of natural gas calculated for the Sable offshore resources in eastern Canada. In the United States, where coalbed methane resource evaluations and production have increased substantially over the past 20 years, 7% (1.34 TCF) of total domestic gas production is derived from coalbed methane. In this period, the cumulative US production of coalbed methane has exceeded 198 billion m3 (7 TCF) and more than 8000 coalbed methane wells have been drilled.In Maritime Canada, the largest coalbed methane resources occur in the offshore areas of the Gulf of St. Lawrence and Sydney Basins where 196 and 26 billion m3 (69 and 9.3 TCF) of gas, respectively, have been projected. In the old mines, the greatest resources are present in the Prince and Phalen mines of the Sydney coalfield, which together contain 1.70 billion m3 (60 BCF) of gas, and in the Westville mine of the Pictou coalfield with 198 million m3 (70 BCF).Vitrinite is the dominant constituent in 27 of the 42 coals examined. Vitrinite/inertinite ratios for these 27 coals range from 4.0 to 8.4. These high values may indicate the presence of highly fractured coals with corresponding high permeability and flow efficiency, favourable for the storage and flow of methane gas. Coal rank has a pronounced effect on coalbed methane generation, and the prime gas zone often lies between 1.2% and 1.6% Ro max. (medium to low volatile bituminous). The prime zone in the Maritimes Basin underlies much of the central and eastern Gulf of St. Lawrence, and extends for significant distances seaward into the offshore Sydney Basin.Coalbed methane production from the very large resources available in Atlantic Canada may provide a valuable and long-lasting energy resource, largely free of polluting components.  相似文献   

11.
Resources Conditions of Coalbed Methane Districts in China   总被引:1,自引:0,他引:1  
The China National Administration of Coal Geology accomplished an assessment of coalbed methaneresources of China in 1988. The total amount of coalbed methane resources in China is 14336.944 billion m , occurring in recoverable coal seams and beneath weathering zones, with coalbed methane content equal to or higher than 4 m3 per ton and buried depths smaller than 2000 m, among which there are 967.51 billion m of predicted reserves and 13369.434 billion m of future reserves. The resources in coal reservoirs with methane content of more than 8 m per ton are 12444.087 billion m , and those with methane content between 4 to 8 m per ton are 1892.856 billion m . There are 35 districts in which the resources abundance is higher than 150 million m3 /km2 , 49 districts with the abundance between 50 million and 150 million m 3/km2 , and 31 districts with the abundance less than 50 million m3 /km2 . There is 9256.078 billion m3 of methane occurring in coal seams with buried depths less than 1500 m, and 5080.866 bi  相似文献   

12.
1 Introduction     
The paper deals with the coalbed methane gas-bearing characteristics such as the gas content, theoretical gas saturation, gas concentration and abundance, as well as coal reservoir characteristics such as the adsorption, desorption and permeability of China's coal reservoirs. The paper also introduces the resources of coalbed methane with a gas content ≥4 m3/t and their distribution in China.  相似文献   

13.
吐哈盆地低煤阶煤层气地质特征与成藏控制因素研究   总被引:3,自引:0,他引:3  
我国低煤阶煤层气资源丰富,气煤以下的低煤阶煤层气资源量15.13×1012m3。迄今为止尚无成功开发先例,地质成藏基础研究亟待加强。论文通过对吐哈盆地煤层气成藏条件、成藏特征分析,探讨了地质构造、聚煤作用、煤系特征、生物气形成与保存等低煤阶煤层气成藏控制因素,初步确定了吐哈盆地煤层气成藏类型及其分布特征,把吐哈盆地煤层气成藏模式划分为盆内凹陷成藏模式、盆缘陡坡成藏模式和盆缘缓坡成藏模式3种类型,根据成藏过程的匹配特征把煤层气藏类型划分为储-逸型低压逸散式、储-运-逸型运移储集式两种类型,该划分方案有助于指导低煤阶煤层气成因研究与资源勘探开发。  相似文献   

14.
多煤层合层开发是提高煤层气井单井产量的关键技术,然而工程实践中大部分煤层合采存在层间干扰问题,致使合采产气量提升不明显。为了提高合层开发煤层气井的产气量与开发效率,以平顶山首山一矿煤层气合采四2煤层和二1煤层为例,基于煤层气赋存的地质条件,分析了合采层间干扰的影响因素及干扰规律,并提出了煤层合层开发层间干扰的控制方法。结果表明:造成四2煤层和二1煤层合层排采产量低的主要因素是储层压力梯度、临界解吸压力和渗透率。其中,两层煤的储层压力梯度分别为1.05 MPa/hm和0.519 MPa/hm;渗透率分别为0.25×10–3 μm2和1.4×10–5 μm2;临界解吸压力分别为1.16~1.69 MPa和0.40~0.46 MPa;另外,两煤层间距大,平均170 m左右。以上主要影响因素差异,造成两层煤合采时层间矛盾突出,干扰严重,总体产量低,井组煤层气开发效率低。基于现状问题,探索提出大间距多煤层大井眼双套管分层控制合采工艺方法,以实现两层煤分开控制达到合采产能叠加的目标,从而提高煤层气井合采产量和开发效果。研究认识将为平顶山及类似地质条件的矿区多煤层煤层气高效合层排采提供新的技术途径。   相似文献   

15.
Permeability changes can be very large during depletion of coalbed methane wells: up to 100 times in the San Juan basin. Analytic models of permeability increase during depletion are accessible, easy to use, and practical. They are more transparent, and less complicated, than coupled numerical models. However, there are minor differences between the analytic models, and these are reviewed here. There are also discrepancies in attempting to match field data, which is the final test of a model, and these are discussed. Two different sets of San Juan data have been modeled, after suppressing the pressure-dependent permeability, with reasonably consistent reservoir parameters. The matching parameters appear to be justifiable, the small porosities do not seem to be ruled out by reservoir experts, and the changes of elastic parameters (including pore–volume compressibility) with depletion do not seem unreasonable. The analytic models are used in reservoir simulators to model and predict injection of greenhouse gases in coal seams. Only when we can match the permeability increase of coalbed methane wells during depletion, will we have the confidence to use the analytic models in reservoir simulators to match or predict sequestration of greenhouse gases such as CO2.  相似文献   

16.
Geologic sequestration in deep unmineable coal seams and enhanced coalbed methane production is a promising choice, economically and environmentally, to reduce anthropogenic gases such as carbon dioxide in the atmosphere. Unmineable coal seams are typically known to adsorb large amounts of carbon dioxide in comparison to the sizeable amounts of sorbed methane, which raises the potential for large scale sequestration projects. During the process of sequestration, carbon dioxide is injected into the coalbed and desorbed methane is produced. The coal matrix is believed to shrink when a gas is desorbed and swell when a gas is sorbed, sometimes causing profound changes in the cleat porosity and permeability of the coal seam. These changes may have significant impact on the reservoir performance. Therefore, it is necessary to understand the combined influence of swelling and shrinkage, and geomechanical properties including elastic modulus, cleat porosity, and permeability of the reservoir.The present paper deals with the influence of swelling and shrinkage on the reservoir performance, and the geomechanical response of the reservoir system during the process of geologic sequestration of carbon dioxide and enhanced coalbed methane production in an actual field project located in northern New Mexico. A three-dimensional swelling and shrinkage model was developed and implemented into an existing reservoir model to understand the influence of geomechanical parameters, as well as swelling and shrinkage properties, on the reservoir performance. Numerical results obtained from the modified simulator were compared to available measured values from that site and previous studies. Results show that swelling and shrinkage, and the combination of geomechanical and operational parameters, have a significant influence on the performance of the reservoir system.  相似文献   

17.
区域构造热事件对高煤阶煤层气富集的控制   总被引:3,自引:0,他引:3  
中国高煤阶含煤盆地经历了多期构造活动影响,使高煤阶煤层气藏具有其独特的复杂性。通过对沁水盆地高煤阶煤层气藏的实例进行剖析,从煤层的热演化程度,煤系地层的方解石脉、石英脉体中的包裹体温度和压力,磷灰石、锆石的裂变径迹古地温分析,中生代火成岩的同位素年龄,岩浆活动产生的大地热流值方面证明了构造热事件的存在。结合煤岩的热解实验分析发现,构造热事件过程中产生的高温、高压的环境促使煤层的生烃,提高了煤层的吸附能力,使沁水盆地煤层的含气量比美国同期形成的黑勇士盆地煤层含气量高5~13m3/t,岩浆侵入产生的温度变化是沁水盆地煤层气含气量欠饱和的原因之一,高温高压的地层环境改善了煤层的物性。  相似文献   

18.
影响煤层渗透率测试的若干因素   总被引:2,自引:0,他引:2  
通过对中国8个矿区10口煤层气评价井的试井工作,讨论了影响煤层渗透率测试的若干因素,认为钻井作业对煤层的伤害、煤体结构及较高的有效地应力是主要影响因素;而煤的变质程度虽然对煤的割理发育起控制作用,但不是煤层渗透率测试的主要影响因素。   相似文献   

19.
采用扫描电镜、压汞试验、等温吸附实验分析贵州金佳矿区8个主要煤层孔隙发育特征。煤储层发育较多的原生孔、气孔及张性裂隙,次生孔隙主要为粒间孔,矿物溶蚀孔、矿物铸模孔相对较少;压汞试验表明,3#煤层开放孔较多,压汞曲线为Ⅱ型,孔隙连通性较好; 1#、7#煤层以微小孔为主,压汞曲线为Ⅰ型,孔隙连通性中等;其余煤层压汞曲线为Ⅲ型,孔隙连通性差;煤储层孔隙度、孔容、比表面积与变质程度呈正相关;甲烷等温吸附实验显示3#、24#煤甲烷吸附速率快,吸附能力最强;矿区煤储层孔隙结构对甲烷吸附性的影响有限;对比分析矿区3#煤层有利于煤层气的开发。  相似文献   

20.
煤中矿物可以影响煤储层物性,进而影响煤层气的开发。运用光学显微镜和扫描电镜研究沁水盆地南部煤中矿物的种类、含量和赋存特征。基于煤储层的平衡水等温吸附实验和压汞实验,研究了沁南地区煤中矿物对煤储层吸附性能和孔渗性能的影响。结果表明,柿庄北区块3号和15号煤平均矿物含量分别为10.68%和12.81%,且15号煤硫化物含量较高。扫描电镜下可观察到充填煤储层胞腔孔、粒间孔隙和微裂隙的方解石、黄铁矿、高岭石和石英。孔隙度和渗透率以及兰氏体积和煤中大中孔比例均随灰分产率的增加而减小,表明煤中矿物的存在会降低煤储层的吸附性能和孔渗性能,煤储层中矿物充填主要影响煤的大中孔和裂隙,影响煤层气在割理和裂隙中的渗流,导致孔隙度和渗透率下降,而少量粘土矿物充填微孔可导致煤的吸附性能下降。  相似文献   

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