RESERVOIR DESCRIPTION FOR MARINE CARBONATE ROCK:A CASE STUDY OF OOLITIC LIMESTONE IN 3RD MEMBER OF FEIXIANGUAN FORMATION IN SOUTH FULING AREA OF SOUTHEAST SICHUAN

Reservoir description in the Fuling area relies mainly on sequence stratigraphy and sedimentary facies analysis, supplemented by seismic parameters, in case there is lack of drilling data. Basic research suggests that the south Fuling area, together with the Jiannan area of western Hubei and eastern Chongqing are all belong to a gentle slope covered by high-energy deposits. In this paper, a depositional model of oolitic beach has been constructed for the 3rd Member of Feixianguan Formation by sequence stratigraphy and previous description of oolitic beach reservoir, its seismic responses and the data from the Well Jian 35 of the Jiannan area. The oolitic beach reservoir migrates with time and forms a superimposed sequence. With this model, we can follow up the favorable distribution area of oolitic beach reservoir or the "bright point" of the 3rd Member of Feixianguan Formation. Upon the basis, using seismic facies and seismic inversion, favorable reservoir and its distribution could be further defined.