Point bar configuration and residual oil analysis based on core and dense well pattern

Abstract

Based on the dense well pattern and the core data of straight wells and horizontal wells of PI332 unit of Putaohua oil layer, Cretaceous Yaojia Formation in Xingbei area of Daqing Oilfield, according to the model of modern sediments and ancient outcrop, the configuration parameters of lateral interbeds configuration are acquired by rock-electricity combination, which are used to analyze the three-dimensional configuration characteristics of the point bar lateral accretion interbeds located in the meandering distributary channel of the delta distributary plain and the residual oil distribution. The results show that the lateral accretion interbeds of point bar are thin, slow, and dense in PI332 unit of Xingbei area. The thickness of interbeds is mainly 2-25 cm. The upper and lower dip angle of interbeds is smaller at 2°-5°. The middle of interbeds is steeper at 7°-10°. The plane distribution density is 0.11/m. The three-dimensional spatial configuration consists of the plane and profile features. The lateral accretion interbeds are in crescent arrangement on the plane, and in imbricate and echelon distribution on the profile. Under the influence of lateral accretion interbeds architecture and the physical difference of lateral accretions, the middle and lower parts of point bars are seriously flooded, and the residual oil is mainly distributed in the middle and upper parts. The horizontal section of a horizontal well should be designed in the middle and upper parts of point bars, and it should drill out the middle and upper parts of lateral accretion bodies to increase the supply unit and enhance oil recovery.