Study On The Main Factors And Its Influence Of Weak Gel Profile Of Fractured Low Permeability Reservoir

Fractured low permeability reservoir has now become one of the important resources of oil and gas exploration and development,and water flooding is the most common and most effective way to develop it.The fracture of fractured low permeability reservoir widely development,water flooding process can lead to water onrush.Weak gel deep profile is an important means of fractured low permeability reservoir high water or flooding large range of solutions,but the effect of weak gel profile is influenced by many factors.In this paper,taking as an example Yanchang eastern oilfield reservoir,Analysing the characteristics of waterflooding of fractured low permeability reservoir,Including its macroscopic reservoir heterogeneity,fracture characteristics,and clearly the main problems existing in the process waterflooding.To solve these problems,this paper conducted a major study of the three major aspects.The first is to study factors from flooding the system's own performance,confirming the suitable crosslinking agent concentration,clearing pH value,temperature and salinity of the gel into the influence of glue and stable performance.By varying different parameters to examine its impact on the effect of weak gel profile,finally confirming the suitable initial viscosity range of weak gel injected,effect of gel suitable injection rate and injection quantity and injection timing of the recovery.Through study examined the effect of a weak gel profile different injection ways,and depending on the experimental observations visualization of single and multi-slug slug injection and sealing effect,finally,the core test screening slug combination.Open-field test results show that weak gel deep profile can effectively block passage of water jump,improve water flooding pressure gradient.By increasing the water swept volume,improve development status fractured reservoir high water district.The injection pressure of water well increased from 3.3Mpa to 6.5Mpa,increased 3.2Mpa averagely.Pressure drop of 7 injection wells is 2 ~ 7.5Mpa,improved obviously.Liquids production of 18 inefficient wells increased by 27.7%,net oil added is 36.5%.7 of 8 shut down wells were reopen to produce oil.The water cut rate of those production wells which moisture content greater than 80% dropped by 11%,valid for more than six months,made a very good "increasing oil precipitation" effect.