Study On Plugging And Transporting Characteristics Of New Temperature-resistant Polymer Microspheres

Polymer microsphere profile control technology is a new type of deep profile control technology developed in recent years.After the polymer microsphere dispersion system enters the formation,it can realize step-by-step deep profile control by plugging and transporting.At present,most of the polymer microspheres used in the mine are below the reservoir temperature of 100 ℃.The temperature resistance of the microspheres is the key to its application in high temperature reservoirs.In view of the temperature resistance of microspheres,two double crosslinked new temperatureresistant polymer microspheres F and W microspheres were prepared in this laboratory,both microspheres can withstand temperatures of up to 180 days at 120 °C.In this paper,optical microscopy,scanning electron microscopy and laser particle size analyzer,microfiltration membrane filtration experiments and cores were used.The displacement experiments studied the microscopic morphology,swelling performance,plugging and transport characteristics and enhanced oil recovery of temperature-resistant F microspheres and W microspheres.The experimental results show that the temperature-resistant F microspheres and W microsphere powders are spherical,the particle size of the F microspheres is about 15～40 μm,the particle size of the W microspheres is between 50～300 nm.After the microspheres swell in water,the shape is still spherical,and the swelling ratio is about 5 times.With the prolongation of swelling time,the particle size of the microspheres first increased and then stabilized.As the swelling temperature increased,the particle size of the microspheres gradually increased.Both microspheres exhibited good temperature resistance at 120 ℃.The microsphere dispersion system which swells at high temperature can effectively block the microporous membrane with a certain pore size.For the F microspheres,as the swelling time of the microspheres is prolonged,the concentration is increased,and the flow rate is increased,the blocking effect of the microspheres is gradually enhanced,and the plugging effect is weakened with the increase of the permeability.As the swelling time of the microspheres prolonged,the concentration increased,the flow rate increased,and the permeability of the filled sand tube increased,the migration effect of the F microsphere dispersion system first increased and then weakened.For the W microspheres,as the swelling time of the microspheres increases,the plugging effect first increases and then weakens.As the concentration increases and the swelling temperature increases,the plugging capacity increases.The plugging effect decreases as the core permeability increases.As the swelling time prolonged,the swelling temperature increased,the concentration increased,and the permeability increased,the migration capacity of the microspheres first increased and then weakened.The W microspheres injected with 1 Vp slug can increase oil recovery by 13.0 % on the basis of water flooding.The W microspheres injected into the 4 Vp slug can increase the recovery factor by 19.0 % on the basis of water flooding.The W microspheres are injected into the heterogeneous double-tube parallel core,preferentially enter the high-permeability core,and block the high-permeability layer,so that the subsequent injection liquid is turned to the low-permeability core,so that the crude oil in the low-permeability core is produced,and microspheres can increase oil recovery by 13.9 % on the basis of water flooding.