Potential Excavation Technology For Thick Formations Of Extra-High Water Cut Period In Lamadian Oilfield

Aiming at the serious heterogeneity, and highly dispersed residual oil in thick formation in extra-high watercut Lamadian oilfield, also based on the further understanding of waterflooded thick layers through detailed reservoir description, a new production technology was developed. Through using and protecting barrier layer or physical interface, the potential tapping was realized, and the corresponding technology was developed. Namely, how to use and protect interface, the separate-layer water injection and plugging are applied to enhance the water injection effect, to control ineffective cycling of injected water, to enlarge the swept volume; through applying separate-layer fracturing technology, the connectivity between the sub depository unit is improved, so the displacement efficiency of medium~low permeability layer was improved; also by applying separate-layer perforation adding, the injection-production in the sub depository unit was improved, the potential tapping was realized.On the basis of detailed reservoir description, aiming at the barrier layer with thickness of less than 0.5m or the physical structure interface, meeting the precondition of avoiding cross flow, this potential tapping technology apply the separate-layer water injection and plugging to increase the effective water injection, to control the ineffective cycling of water, and to increase the swept volume; through applying separate-layer fracturing technology, the connectivity between the sub depository unit is improved, so the displacement efficiency of medium~low permeability layer was improved; also by applying separate-layer perforation adding, the injection-production in the sub depository unit was improved, the potential tapping was realized to increase the oil recovery.