摘要：In view of the dual-media characteristics of low permeability buried hill reservoirs,the fingering and tongue-feeding phenomena are serious during the flooding development process.The flooding phase breaks through prematurely,the crude oil utilization in the matrix is low,and the final oil displacement efficiency is low.In this paper,the laboratory analysis of long lithologic displacement was conducted for the XL low permeability buried hill reservoir block to evaluate the effects of fracturing,displacement media and displacement methods on the development.The experimental results show that the oil displacement efficiency value of the continuous gas injection flooding process before fracturing is 60.98%,the oil displacement efficiency value of the continuous gas injection flooding process after fracturing is 58.93%,and the oil displacement efficiency value of the continuous water injection flooding process after fracturing is 69.94%.The water injection volume during continuous water flooding after fracturing is 1.60PV,the oil displacement efficiency during pulse gas flooding after fracturing is 64.01%,the oil flooding efficiency during pulse water flooding after fracturing is 67.63%,and the water injection volume of the pulse water flooding process after fracturing is 1.92PV.Those results show that the continuous oil flooding process after fracturing is the highest in the final oil displacement efficiency,and it requires less water injection than the pulse water flooding process after fracturing.The experimental research in this paper shows that in the process of dual-media displacement development of low permeability buried hill reservoirs,the continuous water flooding displacement development process after fracturing can communicate well with the matrix and high-permeability channels,and at the same time reduce the breakthrough time of the displacement phase to obtain better oil displacement efficiency.
关键词：Low permeability buried hill reservoir;fracturing;water injection;gas injection;oil displacement efficiency
