The gas test breakthrough of mudstone shale of Taiyuan Formation in Well-MY1 and Well-ZDY2 has proved that the Upper Paleozoic marine-continental transitional shale gas in the South of North China Basin has potential for further tapping resources. Based on the latest data of Well-TX3 and Well-TX4

this paper comprehensively analyzes the shale geochemistry

petrology

reservoir space

physical properties and gas bearing properties of the Taiyuan Formation and Shanxi Formation of the Upper Paleozoic in Tongxu area in the South of

North China Basin

the results show that: ① The organic matter of the mud shales of the Taiyuan and Shanxi Formations comes from the vascular plant and belongs to type Ⅲ Kerogen;

TOC

value is 1.0 %~4.5 % and belongs to good source rock;

R

o

value is 2.4 %~3.4 % and is in the over mature stage. The mud shale reservoir has higher brittle mineral content

which is favorable for the later fracturing reconstruction. ②The reservoir space is dominated by fractures and micro-fractures

followed by inorganic pores

less developed organic pores and isolated distribution. ③Based on the comparison of the gas test results and shale gas evaluation parameters

the shale gas resource potential of Taiyuan Formation is obviously better than that of Shanxi Formation.