吐哈盆地沙尔湖地区煤层气钻完井适用技术探讨

在剖析美国圣胡安盆地煤层气空气钻井、裸眼洞穴完井技术及优势的基础上,确定了低煤阶煤层气钻井及裸眼洞穴完井的煤储层条件等,并以吐哈盆地沙尔湖地区低煤阶煤层气为主要研究对象,利用类比法及地质统计法,具体分析了吐哈盆地沙尔湖地区的煤储层厚度、含气量、渗透率、井壁稳定性及储层压力条件等．研究表明,沙尔湖地区煤层厚度大,储层物性好,井壁稳定性好,可采用低成本空气钻井及裸眼完井技术提高钻井效率,保护煤储层,提高煤层气采收率．     

刘家勘探区煤储层特征及煤层气开发条件研究

研究了刘家勘探区煤储层特征及煤层气开发条件，认为研究区煤储层的煤级，孔隙性和渗透性相对较低，但地质构造简单，煤层气资源丰度高，煤储层厚度，含气量，含气饱和度，甲烷浓度，临储压力比，临界解吸压力等都较高，压力梯度基本正常，可采性以及煤层气开发和利用前景条件较好。并已被煤层气井排采试验结果所初步证实，同时，中也就区内今后的煤层气开发工作提出了某些建议。     

陆相盆地低煤级煤储层特征研究—以准噶尔、吐哈盆地为例

研究了准噶尔、吐哈盆地低煤级煤储层的特征,结果表明：该储层几何形态复杂,且受成煤环境的控制,表现出显著的规律性变化。煤体形态可归纳为与成煤环境对应的4种类型,其中形成于湖成三角洲的朵状、舌状煤体成藏规模最大,浅部煤储层以含气量低、甲烷浓度低、含气饱和度中等、含气强度大为特征;但在构造相对简单的盆缘斜坡深部具有很好的勘探开发潜力,煤储层孔容及比表面积都很大且变化范围也大;中值孔径、孔隙率的变化特征与孔容一致,预示了低煤级煤储层较高的基岩渗透率,兰氏体积和兰氏压力都显著低于中、高煤级煤储层,煤储层达到饱和的机率更大,更容易解吸。古构造应力场控制着煤储层割理裂隙系统的发育程度和分布规律,现代构造应力场特征影响煤储层割理裂隙系统的开合程度,盆缘斜坡多为高渗区。     

Interlayer interference mechanism of multi-seam drainage in a CBM well:An example from Zhucang syncline

Based on the characteristics of the strong volatility of physical property in vertical direction, high gas content, high resource abundance and large exploitation potentiality of coal reservoir in Bide-Santang basin of Zhina coal field, we study the generation mechanism of interlayer interference, propagation rules of reservoir pressure drop and influencing factors of gas productivity in CBM multi-seam drainage in the paper. On the basis of the actual production data of X-2 well of Zhucang syncline in Bide-Santang basin,by simulating the gas production process of a CBM well under the condition of multiple seam with COMET3 numerical simulation software, we analyze the influencing factors of gas productivity during the process of multi-seam drainage, and illuminate the interlayer interference mechanism of multiseam drainage. The results show that permeability, reservoir pressure gradient, critical desorption pressure and fluid supply capacity of stratum have great influence on gas productivity of multi-seam drainage while coal thickness has little influence on it. Permeability, reservoir pressure gradient and fluid supply capacity of stratum affect the propagation velocity of reservoir pressure drop and thereby affect the final gas productivity. Moreover, the influence of critical desorption pressure on gas productivity of multiseam drainage is reflected in the gas breakthrough time and effective desorption area.     

左权高家庄煤矿煤层气开发前景

以左权县高家庄煤矿煤层气普查区内3#和15#煤层为研究对象,研究了该区煤层特征和煤级变化特征,并对煤储层含气性及储层特征进行了分析。结果表明,该区含煤地层地质条件简单,可采煤层厚度大、分布稳定;3、15#为贫煤～无烟煤,变质程度高,煤的变质程度自上而下随煤层层位的降低逐渐增大,煤层生气量大,煤的吸附能力较强;煤层含气量、渗透率等主要储层参数值较高,煤层含气饱和度接近饱和。     

淮北地区煤储层物性及煤层气勘探前景

研究了淮北地区地物构造演化及控气特征,结果认为：淮北地区印支期以来的构造演化对煤储层物性控制作用十分显著,以EW向的宿北断裂为界,北部地区煤层气勘探前景不佳,南部地区的东部,煤层的展布受褶皱形态的控制。在宿面向斜和南坪向斜中,煤层埋深、煤体结构、含气性、含气量和渗透率等储层物性均有利于煤层气的运移、聚集和保存,具有较好的煤层气勘探前景;临涣矿区强变形构造煤发育,煤体结构复杂,基本无勘探前景;涡阳矿区正断层发育,煤层气含量相对较小,但渗透性较好,值得进一步深入研究。     

沁水盆地煤层气地质研究进展

综述沁水盆地煤层气地质的相关研究成果.根据研究,沁水盆地煤层气地质特征可以总结为：主要为高—过成熟的热成因气,仅有少量次生生物气;太原组煤层较山西组煤层吸附性强、渗透性好;煤层的含气性在南部相对较好,在西北部最差;煤层一般发育两组裂隙且以吸附孔为主,盆地南部部分裂隙被热液矿物充填;深成变质与燕山期构造热事件叠加所引起的二次生烃是盆地煤层气藏形成的主要气源,沁南富气区的勘探前景较好.关于煤层气成藏动力场的研究,已经实现了多因素耦合的研究方法.煤层气成藏分析相关研究已经对边界和类型作出划分和厘定.     

高煤级煤储层渗透率在煤层气排采中的动态变化数值模拟

针对高煤级煤储层渗透率尤其是其动态变化规律极少开展研究的现状，基于现代测试技术和沁水盆地排采效果较好的煤层气井实测排采数据，利用目前国际上较为先进的煤层气数值模拟软件CINET2，采用分段拟合的方法对煤层气井的产气、产水过程进行历史拟合和修正，进而对高煤级煤储层渗透率在开采中的动态变化规律进行了探讨．研究结果表明，煤层气并工作制度的变化会引起煤层气井采动状况发生变化，导致煤储层渗透率产生波动．煤储层渗透率随着煤层气井排采时间呈指数规律缓慢衰减，与物理模拟实验结果显示的渗透率与有效应力的关系具有相似的结论．     

水文地质条件对白额勘探区煤层气富集的影响

地下水水动力场对煤层气富集具有明显影响。在研究区东部,煤储层埋藏浅,地下水的径流作用相对较强,煤层气被径流逸散。研究区西南部,煤储层埋藏深,地下水由本区东北浅部向西南深部顺层径流,对煤层中向上扩散的气体起到了封堵作用。矿区西南部为地下水低水位等势面区域,地下水严重滞留,有利于煤层气富集保存,是煤层气富集的有利区域。研究结构显示,地下水化学场特征同样影响煤层气富集。地下水滞留区域与高矿化度中心一致,同样与区域富气中心分布一致。这说明滞留或弱水力交替地下水是煤层气富集成藏的有利水文地质条件。     

Detailed sedimentary facies of a sandstone reservoir in the eastern zone of the Sulige gas field,Ordos Basin

Given sustaining exploration,the eastern zone of the Sulige gas field may soon become a key area of exploitation.In order to explore its genesis,types and distribution of the reservoir sandstones in the eastern zone of this gas field,we focused in our study on the provenance and detailed sedimentary facies of sandstone of the He8(the eighth part of the Shihezi formation,Permian system)and Shanxi1(the first part of the Shanxi formation,Permian system)members,based on core observations,analyses in petrography,granularity and logging.The results show that:1)the sandstone provenance of Shanxi 1 and He8 in the eastern zone of the Sulige gas field is from the north of the Ordos Basin,characterized by dual directions from the north and northeast.2)The He8and Shanxi1 members were deposited in a fluvial-delta sedimentary system.The He8 was mainly deposited in braided rivers,including braided channels,channel bars,levee and floodplain sub-environments,whereas the Shanxi1 Member was deposited in braided rivers and deltas,including braided channels,channel bars,floodplains,tributaries and inter-tributary sub-environments.3)Sedimentary facies bands migrated in drastic fashion towards the basin from the Shanxi1 to the He8 Member.Base levels of sedimentation generally present a trend of small increases in-amplitude,large decreasing amplitudes and slow and gradual Increases.4)The continuity of the reservoir sandbodies along the source direction is better than that perpendicular to the direction.Compared with Shanxi 1,both dimensions and continuity of the sandbodies in He8 are better from which we conclude that it is the most favorable part of the reservoir.     

Detailed sedimentary facies of a sandstone reservoir in the eastern zone of the Sulige gas field,Ordos Basin

Given sustaining exploration, the eastern zone of the Sulige gas field may soon become a key area of exploitation. In order to explore its genesis, types and distribution of the reservoir sandstones in the eastern zone of this gas field, we focused in our study on the provenance and detailed sedimentary facies of sandstone of the He8 (the eighth part of the Shihezi formation, Permian system) and Shanxi1 (the first part of the Shanxi formation, Permian system) members, based on core observations, analyses in petrography, granularity and logging. The results show that: 1) the sandstone provenance of Shanxi1 and He8 in the eastern zone of the Sulige gas field is from the north of the Ordos Basin, characterized by dual directions from the north and northeast. 2) The He8 and Shanxi1 members were deposited in a fluvial-delta sedimentary system. The He8 was mainly deposited in braided rivers, in-cluding braided channels, channel bars, levee and floodplain sub-environments, whereas the Shanxi1 Member was deposited in braided rivers and deltas, including braided channels, channel bars, floodplains, tributaries and inter-tributary sub-environments. 3) Sedimentary facies bands migrated in drastic fashion towards the basin from the Shanxi1 to the He8 Member. Base levels of sedi-mentation generally present a trend of small increases in-amplitude, large decreasing amplitudes and slow and gradual Increases. 4) The continuity of the reservoir sandbodies along the source direction is better than that perpendicular to the direction. Compared with Shanxi1, both dimensions and continuity of the sandbodies in He8 are better from which we conclude that it is the most fa-vorable part of the reservoir.     

沁水盆地郑庄区块构造演化与煤层气成藏

基于沁水盆地郑庄区块的构造发育特征,研究了自二叠纪煤系形成以来该区域构造应力场演化,分析了其对煤层气藏的控制作用,包括构造-埋藏史、后期成藏演化及成藏控制因素.研究表明:郑庄地区主要经历了印支期、燕山期、喜马拉雅早期和喜马拉雅晚期—现代4个期次的构造应力场演化.在构造控制下,二叠纪煤层经历了印支期和燕山中—晚期两次成烃作用,特别是燕山中、晚期煤层生气量巨大,是煤层气的主要成藏期.此后,随着地壳持续抬升剥蚀,煤层埋藏不断变浅,并发育了多组封闭性较好的节理.受南东侧的寺头断层控制,煤层埋深处于600～1 200m,为煤层气成藏以来的最浅埋藏,虽然本区二叠系煤层气的成藏时间较早,但保留的煤层气含量大,煤储层厚度大,且煤层埋藏适中.     

河南省下二叠统山西组二_1煤煤层气储层描述

从煤厚、煤岩组成、煤级、煤体结构、裂隙系统、渗透性、吸附／解吸特性等方面对河南省的主可采煤层二１煤的煤层气的储层特征进行了详细论述．指出镜质组含量较高、割理比较发育、外生裂隙发育适中的原生结构煤和碎裂煤渗透性最好,是最有利的储层;外生裂隙发育适中的无烟煤是有利储层;碎粒煤为不利储层;糜棱煤为不可开发储层．临界解吸压力较高、含气量较高的中煤级煤分布区是煤层气勘探开发的首选地区．     

Reservoir reconstruction technologies for coalbed methane recovery in deep and multiple seams

Multiple coal seams widely develop in the deep Chinese coal-bearing strata. Ground in situ stress and coal seam gas pressure increase continuously with the increase of the mining depth, and coal and gas outburst disasters become increasingly severe. When the coal is very deep, the gas content and pressure will elevate and thus coal seams tends to outburst-prone seams. The safety and economics of exploited firstmined coal seams are tremendously restricted. Meanwhile, the multiple seams occurrence conditions resulted in different methane pressure systems in the coal-bearing strata, which made the reservoir reconstruction of coal difficult. Given the characteristics of low saturation, low permeability, strong anisotropy and soft coal of Chinese coal seams, a single hydraulic fracturing surface well for reservoir reconstruction to pre-drain the coalbed methane(CBM) of multiple seams concurrently under the different gas pressure systems has not yet gained any breakthroughs. Based on analyses of the main features of deep CBM reservoirs in China, current gas control methods and the existing challenges in deep and multiple seams, we proposed a new technology for deep CBM reservoir reconstruction to realize simultaneous high-efficiency coal mining and gas extraction. In particular, we determined the first-mined seam according to the principles of effectiveness and economics, and used hydraulic fracturing surface well to reconstruct the first-mined seam which enlarges the selection range of the first-mined seam. During the process of mining first-mined seam, adjacent coal seams could be reconstructed under the mining effect which promoted high-efficiency pressure relief gas extraction by using spatial and comprehensive gas drainage methods(combination of underground and ground CBM extraction methods). A typical integrated reservoir reconstruction technology, ‘‘One well for triple use", was detailed introduced and successfully applied in the Luling coal mine. The application showed that the proposed technology could effectively promote coal mining safety and simultaneously high-efficiency gas extraction.     

鄂尔多斯盆地东缘煤储层渗流孔隙分形特征

基于压汞试验,分析了鄂尔多斯盆地东缘14个矿区56件煤样储层孔隙的分形特征,通过分维数与煤储层渗透性的比较,得出孔隙体积分维数与煤储层渗流孔隙的渗透性关系.结果表明,煤储层压汞孔隙分形尺度为孔直径86 nm～1 000μm,体积分维数2.75～3.24,在区域分布上呈自北向南降低的趋势,与煤变质程度、灰分、矿物含量呈负相关关系,与水分、中孔含量及视孔隙度(>5%)呈正相关关系.储层渗透性的分形表征与分形维数、分形尺度及分形孔隙的分布连通性多因素相关,但在储层孔隙率较低的情况下,分形孔隙的分布连通情况对渗透性起决定性作用.     

Productivity of coalbed methane wells in southern of Qinshui Basin

Based on regional CBM geological characteristics and drainage data of three typical Coalbed Methane(CBM)wells in the southern Qinshui Basin,history matching,productivity prediction and factor analysis of gas production control are conducted by using COMET3 reservoir modeling software.The results show that in the next 20 years,the cumulative and average daily gas production of the QN01 well are expected to be 800×104 m3 and 1141.1 m3/d,for the QN02 well 878×104 m3 and 1202.7 m3/d and97.5×104 m3 and 133.55 m3/d for the QN03 well.Gas content and reservoir pressure are the key factors controlling gas production in the area; coal thickness,permeability and porosity are less important; the Langmuir volume,Langmuir pressure and adsorption time have relatively small effect.In the process of CBM recovery,the material source and driving force are the key features affecting gas productivity,while the permeation process is relatively important and the desorption process has some impact on gas recovery.     

煤层气成藏的构造应力场研究

构造应力场是控制煤层气成藏极为重要的因素，深入探讨不同性质构造应力场对煤储层的改造及控制机理，将会为煤层气勘探前景评价提供重要的理论基础．本文在区域构造应力场研究的基础上，分别探讨了不同性质构造应力场的作用特征及其对构造发育、构造展布、构造组合及构造变形的控制作用；分析了不同性质构造及其组合、应力-应变环境对煤储层的改造作用，探讨了不同变形机制和不同结构构造煤在不同构造应力场中的发育及展布规律．研究表明，挤压应力场作用下，在强变形带的中心及其附近，可以形成糜棱煤类构造煤，但糜棱煤分布较为局限；在较大范围内形成脆性变形系列的构造煤，是煤层气勘采的有利区带；拉张构造应力场中，大部分区域内有利于煤层裂隙的形成和渗透率的提高，但易造成煤层气的散失，含气量降低，应重视有利的储气构造的研究．剪切构造应力场中，以平移断层为界，煤层的赋存状态、煤体结构和煤储层物性都会存在一定的差异，应对不同的构造单元分别研究其煤储层特征．     

Sorption behavior of coal for implication in coal bed methane an overview

CBM has been recognized as a significant natural gas resource for a long time. Recently, CO_2 sequestration in coalbeds for ECBM has been attracting growing attention because of greater concerns about the effects of greenhouse gases and the emerging commercial significance of CBM. Reservoir-simulation technology,as a useful tool of reservoir development, has the capability to provide us with an economic means to solve complex reservoir-engineering problems with efficiency. The pore structure of coal is highly heterogeneous, and the heterogeneity of the pores depends on the coal type and rank.     

鄂尔多斯盆地东南部下寺湾—云岩区二叠系山西组页岩气形成条件

鄂尔多斯盆地东南部下寺湾—云岩区页岩气资源量较大,二叠系山西组作为主要的目的层系之一.基于钻井资料和暗色泥页岩样品化验资料,从暗色泥页岩生烃条件、储层特征、含气性等方面研究研究区山西组暗色泥页岩中页岩气的形成条件.结果表明:山西组暗色泥页岩分布广泛,且厚度大,平均厚度为80m,有机碳质量分数较高(平均为2.37%),有机质类型以Ⅰ、Ⅱ型为主,成熟度处于成熟—过成熟阶段,具有很强生烃潜力.矿物组成以石英和黏土矿物为主,黏土矿物中主要为伊蒙混层,吸附能力强.硅质、碳酸盐岩等矿物较多,岩石脆性大,造缝能力强.研究区山西组泥页岩中裂缝极为发育,储集条件优越,泥页岩段气测显示活跃,结合页岩含气层显著的测井响应,显示暗色泥页岩段含气性好,页岩气资源潜力较大.鄂尔多斯盆地东南部下寺湾—云岩区二叠系山西组具有良好的页岩气形成地质条件,厚层泥页岩分布区如下寺湾区、云岩区北部黑家堡、关庄及研究区中部延安等,是页岩气成藏的有利发育区.     

鄂尔多斯盆地优质煤资源分布及有利区块

以鄂尔多斯盆地侏罗纪煤炭资源为研究对象,在系统分析煤基本性质的基础上,确定该盆地优质煤的定 义。根据近年鄂尔多斯盆地勘探及聚煤规律研究成果,依据定义确定优质煤主要分布在东胜、榆横、大保当、马家 滩、神北、灵武、彬长、华安、黄陵、汝箕沟10个煤矿区和鄂托克旗、杭锦旗、盐池、靖定、环县、庆阳、旬东7个预测区, 统计含煤面积达11.1×104km2,总资源量1.44×1012t。选择含煤面积、资源丰度、资源量指标对鄂尔多斯盆地优 质煤资源进行评价,划分出最有利、有利、较有利、一般区块,绘制了鄂尔多斯盆地优质煤资源评价分区图。