High Resolution Sequence Analysis and Isochronalstrati-graphic Correlation of Chang 6 Oil Reservoir Set in Pingbei Area

Based on the theoretical system of high resolution sequence stratigraphy, this paper studies the high resolution sequence stratigraphic characteristics of the Chang 6 oil reservoir set of the Upper Triassic in Pingbei area through sedimentary dynamic analysis of cyclic structure and overlapping pattern of the base - level and by using multi -grade base - level cycle dividing scheme. Base - level cyclic interfaces in three grades are identified from this oil reservoir set through comprehensive analysis of core and logging data. The Chang 6 oil reservoir set is divided into short term, medium term and long term cyclic sequences according to the genesis and grade of the interfaces. I-sochronal correlation is performed on the cyclic sequences of each grade by using cyclic isochronal correlation principles and on the basis of cyclic sequence division, and time - stratigraphy frameworks of different scales are established. The significance of sequence stratigraphy frameworks with different time scales in petroleum exploration and production is discussed.