The Research On Effective Production Of Fuyu Reservoir In BY Area

The effective production of ultra-low permeability reservoirs has always been a hot issue in the oil development field,but it is also the weakest link in the research.The research area BY is the exploration focus in Daqing Oilfield in recent years,and the main target layer is Fuyu reservoir.It is a very low permeability reservoir with poor physical property and average air permeability of 2.3m D.Although the oil-water relationship is simple and the reservoir thickness is large,there has been no breakthrough in development for many years.The reason is that the well pattern and fracturing technology are not suitable,The uncertainty of displacement medium and mode is an important and long-term puzzling problem for development decision.In view of the geological characteristics and development difficulties,this paper,based on the laboratory research and field test,realizes the optimization of water drive well pattern layer by means of technological integration and innovation.The development of integral fracturing technology and CO2 flooding reservoir engineering design process provides a reliable basis for the effective production in the western periphery of Daqing.Based on the theory of sequence stratigraphy base-level cycle and sedimentology,the sedimentary microfacies are divided into four types,and the pore structure,fluid and percolation characteristics are clarified by core analysis in laboratory.In the research of water drive well pattern optimization technology,the empirical formula method,numerical simulation technique and economic benefit method are applied to determine the technical limit well spacing and the integral fracturing method of oil and water well.Effective displacement has been realized.In the CO2 engineering design,gas drive experiment technology is mainly used to understand the development mechanism of CO2 flooding,and numerical simulation technology is applied to optimize the pattern of CO2 drive well pattern and the field gas injection scheme.Development of a set of CO2 flooding reservoir engineering design process.Evaluation of water drive development effect: the combination of fracture nets to achieve the effective production,synchronous water injection can maintain a high level of formation pressure and production;The effect of small spacing well is obvious,the production condition of reservoir with permeability greater than 1.0m D is better.Evaluation of gas drive development effect: CO2 flooding can establish effective displacement,natural productivity is low,fracturing productivity is high,CO2 flooding oil well has obvious effect,The recovery rate of formation pressure is fast,the CO2 drive is prone to gas channeling,and periodic gas injection can be effectively controlled.Compared with the development effect of water flooding and gas drive,the suction capacity of gas injection is greater than that of water absorption,which is beneficial to the establishment of displacement system.However,due to the failure to realize miscible flooding,the increase of recovery efficiency is small and the economic benefit is poor.