Distribution Characteristics Of Inefficient And Ineffective Injection And Recovery Circulation In Daqing PⅠ4～GⅠ5 Thick Reservoir Of L6-2027 Well Zone

The reservoir of Lamadian oilfield is mainly fluvial-delta deposition with the thick reservoir.67.5 percent of the thick geological reserves are more than 2 meters in height with bad heterogeneity between layers. Because of longtime injection and recovery, since 1997 Lamadian oilfield has entered the extra-high exploitation stage and injection water cycle along the high permeability and high water cut channels which is called inefficient and ineffective injection and recovery circulation. The distributing characteristics of ineffective injection and recovery circulation in PⅠ4～GⅠ5 thick reservoir of L6-2027 well zone will provide a guidance for water plugging and profile control, injection-production structure adjustment,and increasing reservoir spread volume and recovery.Based on the fine geological description, data from bare well logging and closed coring, dynamic change and monitoring information of oilfield, methods of integrated interpretation, numerical simulation, and dynamic monitoring, this paper investigates the plane and internal characteristics and occurrence time of inefficient and ineffective injection and recovery circulation in PⅠ4～GⅠ5 thick reservoir L6-2027 well zone. The result shows that inefficient and ineffective injection and recovery circulation mainly lies in the deposit of meandering river and braided channel. It laterally mainly lies in the effective injection and recovery area, especially in the subject channel sandstone and high permeability banding sandstone. It vertically lies in the bottom of the single rhythm thick reservoir, generally taking one third of all the reservoir thickness. In the occurrence time, it usually occurs in the extra-high water cut stage with the water ratio more that 90 percent.Surfactant profile control has achieves success in controlling inefficient and ineffective injection and recovery circulation.