Parameters Optimization Of Numerical Simulation For Gas Injection Development In M-zone

Due to the poor physical properties,small porosity,low permeability,and low reservoir utilization,low-permeability reservoirs are characterized by rapid decline in production,rapid increase in water cut,and poor development effect of water flooding.EOR technology is often introduced to improve the development effect,and CO₂ flooding is one of the most promising methods in EOR technology.The permeability of the target block with strong heterogeneity and low oil recovery is about 3.47m D.Four well patterns of square-nine-points,diamond-nine-points,square-five-points and anti-seven-points in the target block are selected as representatives,based on reservoir engineering method,geological modeling and reservoir numerical simulation technology.The research contents are as follows:?1?Analyze the current development of the M block,put forward the problems in the current development,and study the distribution rules of the remaining oil under the current situation;?2?Describe the geological conditions of the target block and establish the geological model of the block.Calculate the geological reserves of the block and compare it with the actual geological reserves to verify the accuracy of the geological model and provide preparation for the establishment of the numerical model below;?3?Based on the geological model,the numerical model of the target block is established.During the history matching process,the parameters are adjusted to obtain a numerical model close to the actual model.The remaining oil distribution of the block is studied,which provides a basis for the next step of development plan;?4?Three gas injection modes of CO₂ continuous gas flooding,CO₂ intermittent gas flooding and CO₂ alternate gas water flooding are optimized.The influencing factors of gas injection include gas injection speed,gas water ratio,gas channeling gas oil ratio control,total amount of gas injection,gas injection working system and well pattern,which provide the most reasonable gas injection scheme for the target block.The research results show that?1?in the late stage of water flooding development of M block,the water content of the reservoir increases and the production declines rapidly.Therefore,further CO₂ flooding is needed to improve the development status of M block;?2?The remaining oil in the M block is distributed in imperfect injection-production areas,interwell retention areas,high structural parts,etc.,showing that the overall distribution is more scattered,but the locality is relatively concentrated,with certain development potential?3?The preferred development plan for block M is gas injection The method uses CO₂ water-gas alternate flooding;water-gas alternate cycle,150 days of gas injection,150 days of water injection;the average daily oil production of a single well is 2m³/d;the square nine-point method well pattern is used;The gas injection rate in a single well is 40000m³/d,the water-gas ratio is 1:1.