SEISMIC IDENTIFICATION OF ORDOVICIAN CARBONATE RESERVOIRS IN WESTERN LUNGU AREA,TARIM BASIN

The buried hills upon the Ordovician weathering crust in the western Lungu area of the Tarim Basin are rich in hydrocarbon resources. However, the distribution of reservoirs is rather complex. There are many types of carbonate reservoirs, such as pore-cave, crack-hole and fracture controlled reservoirs. Each of them has different geophysical reflection features. For example, due to the large wave impedance difference between the internal and surrounding rocks and the frequency attenuation, the pore-cave type reservoir exhibits a beaded reflex in seismic profiles, and the fractured reservoir mainly shows a plate discontinuous reflection with low amplitude. In this paper, different methods were used to deal with the seismic data. For the type of pore-cave reservoir we used frequency division technology and absorption attenuation attributes for forecast, and for the fractured reservoirs, conventional coherence technology was adopted. SEA3D characteristic crack detection technology was used for crack reservoir detecting. Our results fit well with the single well imaging logging and drilling data.