Abstract：Sichuan Basin belongs to hilly area,which is one of main gas-bearing basin and mainly fracturedgas reservoir.In order to find out orientation,density and scope of fracture in the gas-bearing formation,we continuously study the 3-C data exploration method for many years.We make 3-C data acquisition two times insame area of southwest of Sichuan Province within 1O years.The quality of acquired field 3-C data has been greatly improved(after estimation ofquantitative signal-to-noise ratio),which benefitby the progress of acquisition equipment,technique and management.First is renewing the acquisition equipment:studying newtype,practical land3-C geophone,which achieved the designing goalssuch as can be easily laid out,has good coupling toground and without crosstalk,and using 360-cannelTelseis for receiving.Second is the progress of acquisition technique,including designing and optimization of acquisition parameters of system.Thirdis good operation management:carefully monitoring coupling of geophone to the ground,levellingsurvey, orientation of geophone and depth and position of shot,which reduce errors to minimum.
