煤储层特征及其对吸附能力的影响——以鸡西盆地城子河组为例  

Coal Reservoir Characteristics and Their Impacts on Adsorptivity—A Case Study of Chengzihe Formation in Jixi Basin

作　　者：王宇航 王有智[2] 

机构地区：[1]大庆油田第一采油厂,黑龙江大庆163712 [2]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《中国煤炭地质》2016年第8期33-37,67,共6页Coal Geology of China

基　　金：中石油科技攻关项目"煤层气勘探开发关键技术研究与示范工程"(2010E-2201);"大庆探区非常规油气勘探开发关键技术研究与现场试验"(2012E-2603);国家重点基础研究发展计划(2011CB101001);国家科技重大专项(2011ZX05014)

摘　　要：采用扫描电镜、低温氮吸附法对鸡西盆地城子河组煤岩储集空间特征和孔隙结构进行研究,探讨煤岩吸附能力的主要影响因素。结果表明,煤岩常见孔隙类型包括残余组织孔、屑间孔、角砾孔和气孔,其中气孔的广泛发育既证实了煤岩大量生烃的过程,又为煤层气赋存富集提供优质储集空间。形式多样的张性裂隙组合,对改善渗透性具积极意义;煤岩低温氮吸附曲线呈现两种类型,反应不同特征的孔隙系统。鸡东坳陷相对梨树镇坳陷煤岩中微孔更为发育,使得比表面积和总孔体积值较高,平均孔径值降低,孔隙形态从开放性逐渐过渡为墨水瓶孔,微孔中墨水瓶孔的含量是导致滞后环形态发生变化的主要原因;煤岩的比表面积和总孔体积能够较好的反应煤岩的吸附能力。灰分、镜质组含量和成熟度通过控制鸡西盆地城子河组煤岩孔隙发育特征,从而影响煤岩的吸附能力。煤岩镜质组和演化程度升高会增强煤岩的吸附能力,而灰分含量高会减少煤岩对甲烷的吸附量。Through SEM, low temperature nitrogen adsorption methods carried out studies on coal and rock reservoir space characteristics and pore structures, discussed coal and rock adsorptivity main impacting factors. The result has shown that common pore types of coal and rock have residual tissue pore, intraclastic pore, rubble pore and gas pore. In which, wide development of gas pore has not only confirmed coal and rock massive hydrocarbon generation process, but also provided high quality reservoir space for CBM hosting and enrichment. Various forms of tensile fracture combination have positive significance to improve permeability. Coal and rock low temperature nitrogen adsorption curves present two types have reflected two different characteristic pore systems. More developed micropores in coal and rocks of the Jidong depression in contrast to the Lishuzhen depression made higher specific surface area and total pore volume, lower average pore size;pore forms gradually transit from open type to ink bottle type, more ink bottle typed pores are the main causation to result in hysteresis loop form changes. Coal and rock specific surface area and total pore volume can preferably reflect coal and rock adsorptivity. Ash, vitrinite contents have controlled the coal and rock development characteristics in Chengzihe Formation, Jixi Basin, thereby impacted adsorptivity of coal and rocks. Vitrinite and evolution degree promotion will strengthen coal and rock adsorptivity, while high ash content will reduce methane adsorptive capacity.

关 键 词：储集空间类型 孔隙结构 氮气吸附 吸附能力 鸡西盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]