资源描述:
《焦作煤田煤储层物特征及控气因素》由会员上传分享,免费在线阅读,更多相关内容在应用文档-天天文库。
1、摘要煤层气是一种主要以吸附方式赋存于煤层中的清洁能源,我国煤炭资源非常丰富,煤层气资源量也相当可观。研究煤储层的物性特征及含气性,可以为煤层气的开发利用提供借鉴作用,同时也可以减少瓦斯事故的发生。本文利用搜集的资料和实验测试结果,研究了焦作煤田主力煤层二1煤层的储层结构、渗透性、吸附性等物性特征及分布规律,采用定性与定量相结合的方式,对煤层含气性的变化规律及控制因素进行了探讨。研究认为:焦作煤田二1煤层微孔含量最高,其次是过渡孔,而大中孔含量要低得多,具有很强的吸附能力和较强的扩散能力。但渗流或层流能力很弱,煤层渗
2、透率较低,且随着埋深的增加而减小,但地质构造对煤层渗透性具有一定的影响,并且研究区内煤层压裂处理渗透性可明显改善;煤层顶、底板岩性为煤层气体提供了良好的保存条件,而有效埋深、断裂构造对本区煤层含气性具有重要的控制作用。随着有效埋深的增加,含气量先是急剧增大,到了一定阶段后,增大趋势变缓,之间具有对数正相关关系;向斜轴部煤层气含量高于两翼,而背斜则呈现相反的趋势;区域大断裂带附近以及多组断裂的交会部位,煤层含气量往往较低。关键词:焦作煤田;煤层气;储层物性;含气性;控制因素AbstractCoalbedmethane
3、mainlyisakindofcleanenergywhichexistsincoalseaminadsorptionmanner.Coalresourcesareveryabundantinourcountry,thecoalbedmethaneresourcesarealsoconsiderable.Researchingoncoalreservoirphysicalcharacteristicsandgas-bearing,canprovidereferenceforthedevelopmentandutil
4、izationofcoalbedmethane,atthesametimealsocanreducethegasaccidents.Basedonmeasuresoncoalsamplesandthedata,thepropertyoffractureandporestructure,permeabilityandadsorptionoftheⅡ1coalbedmethanereservoirintheJiaozuocoalfieldweresystematicallystudied.Thegas-bearingc
5、hangelawandtheinfluencefactorsongas-bearingpropertieswerediscussedusingqualitativeandquantitativeanalyses.Thestudyshows,microporesarethemajorpore,transitionalporesarethesecondandmacroporesarefarlessintheⅡ1coal,thusforthekindofcoal,theadsorptioncapacityisveryhi
6、ghthediffusibilityisalittlestrong,butthecapacityofseepageandlaminarflowisveryweak.Thepermeabilitycoefficientislowanddecreaseswiththeburialdepthofthecoalbed,andthepermeabilityalsoisinfluencedbythegeo-structureandcanbeimprovedunderhydraulicfracturing.Theroofandf
7、looroftheⅡ1coalbedprovidefavorablegas-preservationconditions,andtheeffectiveburialdepthandfaultsstructurearealsothemajorfactorscausinggas-bearingchangeintheⅡ1coal.Theeffectiveburialdepthandgas-contentisinpositivecorrelation.Thegascontentintheaxialpartofthesync
8、lineisgreaterthanthatinthewings,andtherelationistheveryoppositeintheanticlines.Thegascontentisoftenlowneartheregionalfaultsorintheintersectionpartoftheregionalfaults.Keywords:Jiaoz