Detailed field description and experimental analysis have been carried out for Wufeng-Longmaxi Formation shale profile in Anwen Town

Qijiang

Chongqing

by field profile observations and field measurements. Three kinds of lithology formation

namely black siliceous shale of Wufeng Formation

dark gray shell argillaceous limestone of Guanyinqiao and black shale of Longmaxi Formation

are exposed from bottom to top in shale section of Anwen Town. There are three main conclusions. First

the exposed shale is the main formation of current exploration and development

the indicators of reservoir forming conditions are superior

TOC

ranges from 1.10 % to 8.10 %

with an average of 3

.40 %. The average

R

o

is 2.70 %; Quartz content ranges from 33.90 % to 56.60 %

with an average of 42.36 %

and clay content ranges from 18.00 % to 57.20 %

with an average of 42.62 %. Second

the main reservoir space types are microfracture

organic pore and inorganic pore. Third

combined with the exploration and development practice

the ①~③ subzone of black shale at the lower part of Wufeng-Longmaxi Formation is the sweet spot section

which is a favorable target of horizontal well.