Remaining Distribution In North Search Development Area In The West Of Sabei

This dissertation describes a detailed study of the reservoir heterogeneity and remaining oil distribution of SⅡ, SⅢ, the better oil layers, in North Saertu oil field in Daqing.In research area, the widely varying substrata has the thin effective thickness, low permeability, scattered distribution and obvious heterogeneity .Controlled by sedimentary facies, it has obviously corresponding relationship with the sedimentary facies. For this reason, substrata with thick effective thickness have better permeability. Multiple sedimentary facies association and high-fequency polycycle sedimentation lead to serious interlayer heterogeneity of this area. With laminae and big hierarchical coefficient of SII, SII , permeability heterogeneity differs vastly between substruta. Widely dispersed, thick barrier layers and west-north-ward structural fracture strengthen the interlayer heterogeneity; Plane heterogeneity is in control of sedimentary facies belt, which leads to the directivity of double permeability.According to contributing factors, the remaining oil can be divided into four types(type-I---out of well pattern control ; type-II—with bad permeability; type-III—in remained oil area; type-IV—in barrier bed). While according to the study results, remaining oil in adjusting area mainly consists of injection-production faultiness type, low permeability type and stagnant area type as well as barrier bed type.The analysis result shows that the remaining oil of this area is characterized as: Remaining oil is mainly distributed in thin tabulated beds and untabulated beds with low permeability. Remaining oil scatters widely.Complexity exists in the contact between remaining oil and water flooded layers and zones.Vertically, the remaining oil layers in adjusting area alternates with water breakthrough layers, between them the barrier beds is thin. Horizontally, because of the plane heterogeneity, the relatively good intervals are flooded, so that the remaining oil only exists in margin oil layer owing to faultiness of injection-production; remaining oil is enclosed by waterflooded zone, therefore, it is so complex relationships between remaining oil and waterflooded layers and zones that high requirements are made in the choice of completion optimization.