Daqing Low Penetration Of Water Flooding To Adjust The Technical Studies

Based on the development history of ChaoYang-gou oilfield and TouTai oilfield, this article summarized the experiences and problems occurred in the development of oilfield and analyzed the main existing problems and the principal reasons during the waterflooding. On the basis of these, using the percolation theory of low permeability reservoirs, petroleum reservoir engineering method, numerical simulation technology and economic evaluation method and so on, and combining with laboratory experiments, pilot test and some results of analyzing and assaying the materials of inclosed core test, this essay researched further and systematically some aspects including the law of oil and water motion, the effective displacing system, the well pattern adaptability, the feasibility of well pattern thickening, the reasonable injection-production ratio, the proper injection pressure, the right flowing pressure and the pertinent ratio of injector to producer in the low permeability oil fields. Some important achievements that have been made are as follows:1 Based on geological characteristics and waterflood development of Chao Yang-gou and Toutai oil fields, synthetic adjustment measures centered on the injection to production configuration modification, injection to production system adjustment and well pattern thickening modification are put forward;2 Using field practical materials, the method of calculating start-up pressure gradient is put forward, and relationship between permeability and start-up pressure is determined too;3 Angles between well array and fracture direction are respectively 22.5° and 45° in ChaoYang-gou and TouTai oilfields. According to this development pattern, comprehensive adjustment method that well pattern thickening combines with injection to production system modification, and with imbibition oil recovery is provided.4 Based on the percolation theory, the models for predicting the effects of imbibition mechanics and imbibtion development index are set up, and the conditions suitable for imbibtion oil recovery are provided.5 Theoretical model of injection-production ratio is set up. Researches show that injection to production ratio is not only related to reservoir physical properties but also limited by rational water injection pressure and flowing pressure. In the ideal condition, injection to production ratio turns out to become 1 as the time of waterflood lasts.The achievements and technologies that are obtained in this project not only provide the technical basis for the ChaoYang-gou and TouTai oilfields, but also get used. They enhance the effect of oilfield synthetic adjustment and provide the good example for the development plan and development adjustment of this kind of oilfields.