微纳米尺度下页岩气的质量流量特征分析  

Analysis of the mass flow rate characteristics of the shale gas in micro/nano scale

作　　者：宋付权[1] 刘禹[2] 王常斌[2] 

机构地区：[1]浙江海洋学院石化与能源工程学院,浙江舟山316022 [2]东北石油大学石油工程学院,黑龙江大庆163318

出　　处：《水动力学研究与进展（A辑）》2014年第2期150-156,共7页Chinese Journal of Hydrodynamics

基　　金：国家重点基础研究发展计划(2013CB228002)~~

摘　　要：页岩气流动特征复杂。一些学者已对页岩气渗流进行了探讨,但这些模型大多只包含了页岩气渗流的部分机理。该文基于页岩气藏复杂孔隙结构和页岩气在纳米孔隙表面的滑脱、扩散等现象,通过建立天然气单相流动模型,从质量流量角度,详细阐述了页岩气的流动机理及滑脱、扩散等因素对页岩气流动特征的影响。质量流量的特征研究表明:达西流动产生的流量与地层压力、压力梯度和渗透率成正比;低压下,气体的滑脱效应、扩散效应明显,扩散产生的流量所占比例较大,高压下,渗流以达西流为主;滑脱产生的流量与压力梯度、渗透率成正比,压力梯度和渗透率一定时,滑脱流量为定值,与地层压力无关。扩散对页岩气流动的影响与滑脱相类似:随着地层压力增大,扩散作用明显减弱,扩散产生的流量与压力梯度成正比;扩散流量与渗透率无关,扩散对压力的敏感度大于滑脱。The flow characteristics of the shale gas are complex. Some scholars discussed the seepage of the shale gas, but most of their models contained only part of the mechanism of the shale gas seepage. Considered the complex pore structure and slippage of the shale gas on nanometer pore surface, and the diffusion in the matrix system, the single phase flow model of natural gas is established, and the flow mechanism and the shale gas flow characteristics affected by the slippage and the diffusion are analyzed. The researches of the characteristics of the mass flow rate show that： the Darcy flow rate is proportional to the formation pressure, the pressure gradient and permeability. The slippage and the diffusion obviously influence the gas flowin low pressure and the diffusion flow rate is larger than the slip flow rate, but the Darcy flow mainly influences the seepage in high pressure. The Slip flow rate is proportional to the pressure gradient and permeability and it is a constant value with different formation pressures in condition of same pressure gradient and same permeability. The diffusion effect to shale gas flow is similar with the slip effect： the diffusion flow rate is proportional to the pressure gradient and has nothing to do with the permeability, the sensitivity of the diffusion effect to the shale gas flow is greater than the slip effect for the zone pressure.

关 键 词：页岩气 渗流 滑脱 扩散 

分 类 号：TE312[石油与天然气工程—油气田开发工程]