CAJ | 학술논문

采用数值模拟、扫描电镜、低温氮吸附曲线对呼和湖凹陷不同构造位置煤岩储集空间类型和孔隙结构特征进行系统研究，分析构造作用对孔隙系统的控制作用，探讨不同压力下甲烷气体在纳米级孔隙中扩散方式。研究表明：①洼槽区以原生孔隙和内生裂缝为主；斜坡带构造相对活跃，以反映构造行迹的碎粒孔和张性、剪性裂缝为主，裂缝数量明显增多，规模扩大，对改善渗透性意义较大。②煤岩孔隙的比表面积与孔体积具有较好的正相关关系，与平均孔径呈负相关性，斜坡带孔隙遭到破坏，微孔数量增多，比表面积和孔体积较洼槽区成倍增长，煤岩对甲烷的吸附能力增强。利用吸附、脱附曲线特征对煤岩孔隙结构特征进行评价，斜坡带相对于洼槽区孔隙系统复杂，利于吸附，难于解吸。③斜坡带和洼槽区在采气初期甲烷以分子扩散为主，随着压力的降低，由于孔隙结构的差异性，开采后期洼槽区甲烷分子逐渐由过渡区流动取代分子扩散，斜坡区扩散方式则变化不大。综合分析认为，斜坡带是呼和湖凹陷煤层气勘探的有利区块。
채용수치모의、소묘전경、저온담흡부곡선대호화호요함불동구조위치매암저집공간류형화공극결구특정진행계통연구，분석구조작용대공극계통적공제작용，탐토불동압력하갑완기체재납미급공극중확산방식。연구표명：①와조구이원생공극화내생렬봉위주；사파대구조상대활약，이반영구조행적적쇄립공화장성、전성렬봉위주，렬봉수량명현증다，규모확대，대개선삼투성의의교대。②매암공극적비표면적여공체적구유교호적정상관관계，여평균공경정부상관성，사파대공극조도파배，미공수량증다，비표면적화공체적교와조구성배증장，매암대갑완적흡부능력증강。이용흡부、탈부곡선특정대매암공극결구특정진행평개，사파대상대우와조구공극계통복잡，리우흡부，난우해흡。③사파대화와조구재채기초기갑완이분자확산위주，수착압력적강저，유우공극결구적차이성，개채후기와조구갑완분자축점유과도구류동취대분자확산，사파구확산방식칙변화불대。종합분석인위，사파대시호화호요함매층기감탐적유리구괴。
Using numerical simulation, scanning electron microscope (SEM) and low temperature nitrogen adsorption methods carried out systematic study on Hoh Lake depression different structural position coal and rock reservoir space type, pore structure characteris?tics, analyzed structural controlling on pore system, discussed methane diffusion mode among nanoscale pores under different pres?sures. The study has shown:①In depressed groove area have mainly protogenic pores and endogenetic fissures, in slope belt has rela?tively active structure activities, thus have mainly disintegrated pores and tension, shearing fissures reflected structural features, fissure number has obviously increased, scope expanded, thus largely improved permeability.②Coal and rock pore specific surface and vol?ume has better positive correlation, while negatively correlated with mean pore diameter, pores in slope belt have been destructed, num?ber of micropores increased, specific surface and pore volume several times over than in depressed groove area, methane adsorptivity of coal and rock increased. Using adsorptive, desorptive curve characteristics carried out evaluation on coal and rock pore structure char?acteristics, pore system in slope belt is relatively complex than in depressed groove area, beneficial to adsorption, difficult for desorp?tion.③During initial gas production stage, methane in slope belt and depressed groove area is mainly molecular diffusion, along with pressure lowering down, since the difference of pore structures, during the later production stage, methane diffusion in depressed area gradually replaced from molecular diffusion by transitional flow, while in slope belt did not changed much. The overall analysis consid?ered that in the slope belt has beneficial blocks for CBM exploration in Hoh Lake depression.