Abstract:

By using the high-resolution sequence stratigraphy theory,through depositional dynamic analysis,the cores of 20 wells and 496 well logging data,Putaohua reservoir of the Talaha-Qijia area in Songliao Basin is divided as 1 long-term base level cycles,3 medium-term base level cycles,8 short-term base level cycles,proposed a new framework with the sedimentary structure lifting control the north and west of Putaohua reservoir. Fine study of sedimentary characteristics reveals that the most favorable facies sandbody is narrow submarine river sandbody, thin channel-mouth bar and sheet sanbody. In the northern half of the study area a large number of broad thick favorable submarine river sandbody is not oily but water-bearing zone.It is realized that sandbody development and distribution of lithologic reservoirs are controlled by a slope break. Area within slope break is the LST for the center of mass deposition, which is thick or thin layer of sandstone, and can form the stratigraphic overlapped traps. Area under the slope break is the delta front facies sandstone superimposed zone of LST and TST of 3 sequences with the development of thin sandstone and poor connectivity, and is a multi-layer lithologic trap development zone. Area above the slope break has a large number of plain and front facies thick channel sand body of TST. Its connectivity is good, so oil and gas are easily lost and difficult to form a lithologic trap.This area had become a large-scale water-bearing zone. All shows that “the slope break controls the distribution of stratum,facies,sands,traps and oil reservoirs” theory has once again been an excellent application and verification in the study area.

Key words: deposition , characteristic, reservoir characteristic, slope break control trap, the Talaha-Qijia area;Songliao Basin