Mechanical Properties Of Rocks And Coals As Well As Fracturing Renovation Of Coal Reservoirs In Bide-santang Basin

Mechanical properties of coals and roof/floor rocks and the relationship between themare the important factors affecting the effect of coal reservoir fracturing engineering.According to mechanics experiment of coal and rock samples from Bide-Santang basin,this paper analyzes mechanical properties of coals and roof/floor rocks and the changes ofthem at the regional and vertical, discusses the geological controlling factors of theirmechanical properties and the differences between them; constructs the predicting modelof coals and roof/floor rocks, and primary analyzes the applicability of fracturingtechnology in different regions of study area.The results show that, Sedimentary environment of study area is the main geologicalfactors that control the mechanics properties of coals and roof/floor rocks and thedifferences between them. Based on the changes of sedimentary environment of the coalbearing strata, this paper could generally predict the regional and domain distribution ofcoals and rocks mechanics properties and the differences between them. The region, fromthe basin in the northwest to the southeast the difference of compressive strength betweencoals and roof/floor rocks gradually becomes large; the vertical, the difference is bigger inLongtan Formation lower segment, and is small in the upper Longtan Formation, in theChangxin group it increases again. In the three grade sequence, at the transgressive systemtract, along with the relative sea-level rise, the strength difference between coals androof/floor rocks is progressively larger, near the maximum transgressive surface, thisdifference is most obvious; while in the highstand system tract, along with the decrease ofrelative sea level the difference is progressively smaller, near the minimum sequenceboundary, this difference is smallest. the region, Zhucang and Agong syncline wherelocated in the east–southeast of the basin are suitable for the implementation of the coalreservoir fracturing engineering, among them, Feiyi and Wenjiaba are most powerfulfracturing sections; Layer domain, the coal seam of longtan group under section ofZhuchang and Agong syncline is suitable for fracturing,23coal seam is the most suitablefor coal seam fracturing.