Recognition of auto-cycle and allo-cycie and its role in strata correlation of reservoirs

Key words:  sequence stratigraphy  auto-cylce  allo-cycle  strata correlation of reservior  correlation models

Abstract:

On the basis of the analysis of the developing background, controlling factors and the scale of auto-cycle and al]o-cycle，the recognition method of auto-cycle and the effects and alternation of auto-cycle on allo-cycle were discussed. The results show that the lower frequency scale sequence or cycle(1-4 scale) are allo-cycle produced by base level change, middle frequency scale sequence or cycle(5-6 scale) are allo-cycle reformed or highly effected by auto-cycle, high frequency scale sequence or cycle(higher than 7 scale) are auto-cycle. The characteristics of allo-cycle are frequently destroyed by auto-cycle, which makes it difficult to do correlation according to allo-cycle. But the auto-cycle can be recognized by correlating the correlation profiles which are parallel and perpendicular to the sedimentary source direction. The characterizeti and widely spread event deposits( auto-cycle) are important to the high frequency scale strata correlation. Because the resolution of seismic profile is lower, its role in the strata correlation of reservoir scale is small, so correlation models are needed to be developed.