Abstract:

This paper represents that the sedimentary rhythm is a primary factor to control the distribution of water flooded zones in the thick-layer sand. The electrical properties of layers in the same well are comparable and the water flooded level discrimination has more practical significance only in the same sedimentary rhythm.The stable mudstone barrier bed is adopted as the separable symbol for different interpretation units that are identified from well logging curve so that only one sedimentary rhythm is contained in each interpretation unit. The average slope angle of resistivity curve and relative center of gravity of density curve are adopted as discriminant parameters for identifying the original sedimentary rhythm by computer in each interpretation unit. The processing results of three sealed core wells show that this method can discriminate accurately the original sedimentary rhythm, therefore, the interpretation coincidental rate is up to 92.5% compared to the manual interpretation.

Key words: original sedimentary rhythm, interpretation unit, level of water flooded, relative center of gravity, average slope angle, well logging