CAJ | 학술논문

致密砂岩储层岩性致密,自生粘土矿物类型丰富且含量高,造成致密砂岩储层晶间微孔发育,岩石比表面积巨大,实验测得平均比表面积为2.13 m~2/g.在储层发育的纳微尺度空间内,天然气分子在其中的赋存状态以吸附为主,一旦微孔介质中天然气浓度发生变化,克努森数大于10时,吸附天然气将解吸、扩散、运移.实验室测定致密砂岩天然气扩散系数平均为6.86×10~(-5)m~2/s,通过模拟典型致密砂岩气井生产周期内天然气扩散量,证实扩散是致密砂岩天然气重要产出方式之一.
치밀사암저층암성치밀,자생점토광물류형봉부차함량고,조성치밀사암저층정간미공발육,암석비표면적거대,실험측득평균비표면적위2.13 m~2/g.재저층발육적납미척도공간내,천연기분자재기중적부존상태이흡부위주,일단미공개질중천연기농도발생변화,극노삼수대우10시,흡부천연기장해흡、확산、운이.실험실측정치밀사암천연기확산계수평균위6.86×10~(-5)m~2/s,통과모의전형치밀사암기정생산주기내천연기확산량,증실확산시치밀사암천연기중요산출방식지일.
In tight sandstone gas reservoir,there is high content of clay mineral,which provides abundant intercrystal pores and surface area compared with conventional reservoir.Experiment reveals that the average specific surface area of tight sandstone is 2.13 m~2/g.Natural gas will be adsorbed in the micro-nano spaces.When Knudsen number is greater than 10,adsorption gas will display desorption,diffusion,migration.Average diffusion coefficient of the gas in tight sandstone is 6.86×10~(-5)m~2/s.Simulation of gas well diffusive flux for typical tight sandstone shows that diffusion is one of the very important ways to tight sandstone gas mass transfer during production.