Evaluation Of Hydration Expansion And Plugging Performance Of Micro Nano Water Plugging Agent

China's economy is growing,and the consumption of petroleum energy is also increasing.But the development and exploitation of oil is becoming more and more difficult.Inhomogeneous reservoirs in China account for a large proportion of the oil fields,and most of them have already stepped into the development stage of ultra high water cut.In order to solve the problem of low recovery rate and high water production,most oilfields in China began to combine the profile control with water flooding at high water cut stage.Based on profile control,micro and nano water plugging materials are used to penetrate deep formations and expand the sweep volume of water drive,so as to effectively improve the final oil recovery.The micro nanoscale water plugging agent in deep water plugging and profile control should not only be injected into the stratum,but also can be blocked,and the effect of water injection pressure on the plugging agent can be effectively controlled.Only in this way the effective closure of the deep stratum can be realized and the sealing can be sustained and steady.In this paper,four kinds of swelled micro-nano materials were selected as temporary plugging agents.The material has the properties of high temperature resistance,salt resistance,viscoelasticity and controllable particle size,and can rapidly expand after water absorption,resulting in plugging.First of all,the basic properties of the four kinds of micro nano water plugging materials were analyzed,respectively discuss the morphology and grain size,expansion,dispersion,stability,corrosion resistance and viscoelasticity;Then the hydration expansion of the four kinds of materials were studied and in the four preferred performance in the sample the best sample;Then from the temperature,time,pH value,permeability,mineralization degree of the five aspects to study its effect on particle size factors;Finally completed the core flow test,comprehensive evaluation of selected samples in simulated rock plugging and particle migration,respectively using particle unexpanded and expanded particle verification the plugging and migration.The results show that the nanoscale water plugging material has good expansibility,viscoelasticity,stability and dispersion,and has high safety and low cost.The size of particle size increases with the increase of temperature,and increases with time,and both pH and osmosis will have a certain effect on the size of the particle.It has high plugging rate for middle and high permeability formations.It can effectively block high permeability area and achieve better plugging effect,and it can continuously migrate and block in core,and go deep into core.And its size range is very wide,from a few microns to thousands of microns,can be suitable for different pore size of the stratum.