【作者】 李日富；

【导师】 司鹄； 文光才；

【作者基本信息】 重庆大学 ， 矿业工程， 2014， 博士

【摘要】 能源是当今社会发展的三大支柱之一，随着我国经济的迅猛发展，能源短缺问题已经凸现。煤矿区煤层气作为一种高能洁净的能源，其探勘、开发和利用技术越来越受到世界各国的重视，在未来必将成为能源领域的研究热点。采动稳定区煤层气地面井抽采技术是上世纪90年代后期发展起来的一种煤层气开发方式，其能够充分利用煤层开采的卸压增透效应，避开岩层的剧烈活动期，实现地面抽采井寿命的最大化，在我国发展前景良好。由于地面井施工成本较高，煤层气开发区域产前选区和经济利益的对比分析必不可少，这就需要提前评估目标区域的煤层气资源量。然而在国内外煤矿界，至今尚未形成一套较完整的采动稳定区煤层气资源量评估技术。论文应用理论分析、数值模拟及现场试验等方法对采动稳定区煤层气储层空间及资源量评估技术进行了系统研究，主要研究工作如下：1、基于煤层采动影响的角度提出采动稳定区的定义，结合传统储集层的概念和采动稳定区的特点定义了采动稳定区煤层气储层的概念，描述了储层的主要特征：采动稳定区煤层气储层具有自然和人工的双重属性，采动稳定区煤层气储层的几何形态及边界条件和储层结构及裂隙两大要素是其区别于传统煤储层的关键性内容，采区围岩有效卸压裂隙场是采动稳定区煤层气储层空间的重要组成部分。2、研究了煤层围岩采动裂隙场的演化过程，通过分析采动裂隙的分布规律提出稳定区煤层气储层的范围及其空间形态特征：采动稳定区煤层气储层主要存在于煤层顶板的“冒落带”和“裂隙带”以及煤层底板的“导气裂隙带”，其高度主要受覆岩关键层层位控制，宽度主要受采场尺寸及围岩岩性影响；采动稳定区煤层气储层在空间上一般呈现“柱帽”形态，工程上可简化为“棱柱”形态。3、基于“三下”煤炭开采理论、保护层开采理论和覆岩关键层等理论建立了采动稳定区煤层气储层范围的计算方法，认为储层范围可以利用采场顶板导气（水）裂隙角、顶板裂隙带高度、底板卸压边界角及底板裂隙带深度四大参数确定，并利用井下现场考察和数值模拟试验验证了计算方法的合理性。4、分析了采动稳定区煤层气资源量评估与传统煤层气资源量评估的联系与区别，构建出适用于不同井下资料完整程度的直接加法及间接减法两种采动稳定区煤层气资源量评估模型，并结合传统油气藏的盖层理论和“三下”煤炭开采理论提出模型的适用条件，同时对模型的关键参数进行了深入研究，提出各自的合理计算方法或者取值方法。5、基于传统气藏资源储量评估的选区原则，结合采动稳定区煤层气储层的自身特点，提出采动稳定区煤层气资源量评价选区的主要原则和基本步骤，并根据井下资料收集情况选用直接加法评估技术对松藻石壕煤矿某目标区域的煤层气资源量进行了评估，证实了评估技术的可操作性。更多还原

【Abstract】 Energy is one of the three pillars of development in today’s society, and the crisisof “energy shortage” has become more and more serious with the rapid developmentof China’s economy. As a high-energy clean energy, the technologies about CBM ofexploring, developing and utilizing have been paid more and more attentions by everycountry in the world, which means CBM is becoming a research hotspot in the field ofenergy.The technology draining CBM with surface borehole from stabilition regionafter mining has developped up since the late1990s,because it can make full use of coalmining pressure relief effect and avoid the strenuous activity period of undergroundrock strata, realizing ground pumping well lifetime maximization, the technology hascaused the major mines’ attention and interest, which means the glorious development prospect in China. Because of the high ground well construction cost, it is necessary toselect the CBM development area and analyze economic benefit before production,which requires early resource evaluation of CBM in the target area. However, there isno a relatively complete assessment method for CBM resources in stabilization regionafter mining yet.This paper combines the method of theoretical research and caseanalysis, inheritance and innovation, summarized innovative methods to study on the reservoir andresource evaluation technique of CBM in mining stabile region in the following aspects:(1) Paper proposed definition of mining stable region from the perspective ofmining influence,defined the concept of CBM reservoirs combined with the traditionalconcepts of reservoirs and the characteristic of mining stable region, and discuss thedescription of mining stable region of coalbed methane reservoir:The CBM reservoir in mining stable region has dual attributes of natural andartificial. Natural attribute refers to the carrier is still the coal and rock, artificialattributes refer to its size associates with the mine production activities closely. Thegeometry&boundary conditions and structure of reservoir&fracture are the twokey contents for reservoir in mining stable region different from the traditional coalreservoir, and the effective unloading fissure field in rocks, difficulty for research, is animportant part to stable region reservoir.(2) The prime location and the spatial behavior characteristics of stable area CBMreservoir were studied by analyzing the experimental data and two-dimensional numerical simulation:The CBM reservoir,which is controlled by the key strata in height and affected bythe stope size&surrounding rocks in width, mainly lies in “caving zone and fracturedzone” in coal seam roof and "gas conductive fracture zone" in floor. Its space formshows “column cap” generally, but can be simplified as “prism form” inengineering.(3)The paper summed up calculation methods for the CBM reservoir instabilization region after mining, using the four parameters such as gas (water) fractureangle in stope roof, the height of roof fracture zone, bottom pressure boundary angleand floor crack depth, based on “coal mining under three circumstances”,“miningprotection layer theory”and “the key strata theory”. The rationality of methods wereverified by the field test and numerical simulation subsequently.(4) On the basis of analyzing the relation and difference between mining stablezone coalbed methane reserves evaluation and traditional coal seam gas reservesevaluation, the two kinds of evaluation models, direct addition and indirect subtraction,for coalbed methane reserves in stable region mining were built, with the calculation orvaluation method for each key parameter. The two models are applicable in differentsituations due to the complete degree of mine production and geological data. Besides,the application condition of models was formed according to the modeling method,the traditional cover theory and coal mining theory under three circumstances.(5) According to the gas producing interval selection principles of traditional gasreservoir reserves evaluation, the main selection principles and basic steps for CBMresources evaluation in mining stable region was picked up, combining with thecharacteristics of mining stable region reservoir. At last, the thesis estimated the coalbedmethane resources in a test area in Shihao mine by using “the direct addition”resource evaluation method, which confirmed the operability of evaluation technology.更多还原