CAJ | 학술논문

页岩气作为一种重要的非常规天然气资源已受到普遍关注，但页岩储层主要发育纳米孔隙，而针对页岩气在纳米孔喉中运移的研究还相对滞后，这严重制约了页岩气藏的高效开发。针对纳米尺度孔隙，考虑页岩气的吸附解吸及吸附相表面扩散，自由气的黏性流、滑脱效应及Knudsen扩散等运移机制，建立了页岩气单相流动数学模型，并开展了流动模拟研究。模拟结果表明：对于以纳米孔隙为主的页岩基质，甲烷在孔隙壁面的附着及表面扩散、气体滑脱及Knudsen扩散等均将影响气体流动，造成表观渗透率显著高于Darcy渗透率，且孔喉越细小，压力越低，表观渗透率与Darcy渗透率相差越大。通过分析各运移机制对页岩气流动的影响，有助于深入了解页岩气运移产出过程，从而指导页岩气藏的有效、高效开发。
혈암기작위일충중요적비상규천연기자원이수도보편관주，단혈암저층주요발육납미공극，이침대혈암기재납미공후중운이적연구환상대체후，저엄중제약료혈암기장적고효개발。침대납미척도공극，고필혈암기적흡부해흡급흡부상표면확산，자유기적점성류、활탈효응급Knudsen확산등운이궤제，건립료혈암기단상류동수학모형，병개전료류동모의연구。모의결과표명：대우이납미공극위주적혈암기질，갑완재공극벽면적부착급표면확산、기체활탈급Knudsen확산등균장영향기체류동，조성표관삼투솔현저고우Darcy삼투솔，차공후월세소，압력월저，표관삼투솔여Darcy삼투솔상차월대。통과분석각운이궤제대혈암기류동적영향，유조우심입료해혈암기운이산출과정，종이지도혈암기장적유효、고효개발。
As an important unconventional natural gas resources,shale gas has aroused wide concern. Shale-gas deposits are abundant in nano-scale pores. However,the study on the gas flow mechanism is still inadequate,which restricts the efficient development of shale gas reservoirs. For nanometer pores,a novel single component mathematical model of shale gas which takes into consideration the adsorption-desorption of shale gas,the surface diffusion of the adsorbed phase,Darcy flow,and slip flow as well as Knudsen diffusion is proposed. The simulation results show that for shale matrix containing a large number of nano-scale pores,methane adsorbed on the pore,the seepage flow and Knudsen diffusion all exert influences on gas flow and make the apparent permeability much higher than absolute permeability. The smaller the pore size and the lower the pressure is,the larger the difference between the apparent permeability and absolute permeability is. The study of the impact of various transport mechanisms on gas flow is helpful to understand the process of shale gas production and to guide the development of shale gas reservoir.