Open AccessMicro-storage State and Mechanism of Shale Gas
Author(s) -
Tianyi Zhao,
Zhao Peng,
Gang Chen,
Lingyu Tian,
Hui Qiao,
Qianwen Li
Publication year - 2020
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/571/1/012008
Subject(s) - adsorption , oil shale , natural gas , chemistry , shale gas , mineralogy , chemical engineering , petroleum engineering , geology , waste management , organic chemistry , engineering
Shale gas has attracted increasing attention as a new potential source of natural gas in recent years. Accurate micro-storage and mechanism of shale gas is important for defining and describing the adsorption characteristics, gas-in-place estimates. Organic-rich shale gas reservoirs were usually deposited under water environment which has great impact on shale gas adsorption. Different from the widely used solid-gas interface adsorption theory, the pore system in original shale reservoir is divided into solid-gas system and solid-liquid-gas system. In same statement, shale pores have stronger interaction with water molecules than CH 4 molecules, especially in solid-gas system. Water molecules mainly formed as competitive adsorption with shale gas on solid surface (solid-gas system) and liquid water surface (solid-liquid-gas system). Maxim gravitational potential energy, Ψ max , the distance where Ψ max occurs, z m and limited pore side, D L are given. When pore size D < D L , no matter in what position the adsorbed molecules is, it force by both sides of the pore silts. When D > D L , the ratio of unaffected area increases to approximately 100% with pore side. When D 50 nm, the ratio of unaffected area almost reaches 100%, which means that the content of free gas is far greater than the adsorbed gas. This study not only provides a new classification of shale pore system, but also can act as a reference to better understanding the adsorption mechanism of shale reservoir.