Anisotropy characteristics of Jia 2 gas reservoir in Mainan structure

Mud logging,well logging and petrophysical data show that the lithology of T1j22 formation are mainly limestone and dolomite,the lithology and formation depth are stable and seal rocks,which are widely distributed above and below the formation.Reservoir is mainly composed of pores,fracture type comes second.Filled fractures are highly developed, fracture dips varies and fracture effectiveness is poor. The reservoir property is characterized by low porosity and low permeability,the reservoir is not well developed and is mainly made up of typeⅢreservoir with multiple layers and small thickness.The better typeⅠand typeⅡreservoirs are distributed in the structural crest and southern axle with the small area.The reservoir relative property is weak and different scales of reservoirs are formed.The gas well productivity varies and the acid stimulation effect is obvious,daily gas production and cumulative produced gas have proved the reservoir property differs greatly and and has an uneven distribution.