In order to study the evaluation standard of deep shale reservoirs

their micro pore characteristics have been studied.Based on the ideas of micro pore structure research with "high precision and cross scale"

and by using nitrogen adsorption

high pressure mercury injection

scanning electron microscope and mineral analysis electron microscope experiments

a series of quantitative characterization techniques of reservoir micro pore structure with full pore s

ize range are formed

and the evaluation standard of deep shale gas reservoir is established.The research results show that:①The pore types include organic pore

intergranular pore

intragranular pore and microfracture

which are of great difference with each other.The organic pores are dominant with the surface porosity more than 50%

the pore morphology is complex with the distribution of elliptic

irregular or flat

the shape coefficient is 0.50～0.90

and the fractal dimension（D） is 2.72 ～2.92.② Based on the full pore size characterization technology and fractal theory

the pore structure can be divided into four types.The organic pores of type Ⅰ pore structure are developed（organic pore ratio Is greater than or equal to 50%）

well sorted（sorting coefficient Is greater than or equal to 0.7）

large coefficient of variation（variation coefficient Is greater than or equal to 1.1）

and multi-modal distribution of pore size.③According to the classification of pore structure and reservoir parameters

shale reservoirs are divided into four types.The key parameters make up the structure of type Ⅰ are TOC≥4%

total gas content Is greater than or equal to 6 m

3

/t

porosity Is greater than or equal to 6 %

brittle mineral content Is greater than or equal to 50 %

Young’s modulus Is greater than or equal to 36 GPa

Poisson s ratio Is less than or equal to 0.225

and type Ⅰ pore structure.This kind of reservoir is mainly distributed in 2-3

1

layers

which is the optimal target window position.