Study On The Matching Relationship Between SMG And Pore Throat And The Effect Of Profile Control And Displacement

Bulk swelling particle is an economical and practical profile control agent and widely used in the high water cut and/or strong heterogeneous reservoirs based due to its good deep migration and plugging ability.The successful application of bulk swelling particle depends on its matching relationship with formations.In this study,the static performance,reservoir matching relationship,profile control and displacement effect,migration and plugging mechanism of one kind of adaptive microgel particle(SMG)are analyzed through macro displacement and microfluidic experiments.The static performances of SMG were evaluated by SEM and laser particle size analyzer.The matching factor considering the median size and distribution range of SMG particles and cores is established.The matching relationship between the SMG and the core is revealed through the long core migration experiment.The deep migration ability of SMG is verified by scanning the core section using SEM.The effects of the permeability ratio and injection system on displacement are evaluated by parallel core experiments.The migration,plugging and oil displacement of SMG in porous media are investigated by microfluidic experiments.The results show that the SMG aqueous solution has robust stability,uniform particle size distribution.The swelling ratio positively correlated with the aging time and temperature,and is negatively correlated with the salinity.With the increase of microsphere concentration,the best matching factor between SMG and pore throat seems to be smaller.When the mass concentration of SMG is 0.1%,0.2% and 0.3%,the best matching factor ranges from 1.28 to 2.10,0.92 to 1.48 and 0.77 to 1.28,respectively.When the permeability of the high permeability layer is in the range of the best matching factor,SMG gains the best profile improvement and EOR efficiency.The composite system of SMG and polymer has a better effect of reducing water and increasing oil.There are four plugging forms of SMG: direct plugging,bridging plugging,superimposed plugging and hydrodynamic plugging.The blocked particles can realize inward migration and plugging to expand swept volume by passing through the pore throats through their deformation ability.