Evaluation of polymer microsphere profile control and flooding effect in G block of Jiyuan oilfield
G block of Jiyuan oilfield is a typical ultra-low permeability reservoir.In the process of water injection development,the water cut rise speed is accelerated,the produc-tion decline is increased,and the uneven water drive contradiction is prominent.The initial particle size of polymer microspheres is small,and the injectability and migration are good.After the microspheres are injected into the formation,the hydration expansion blocks the dominant water drive channel,so as to improve the water drive effect.From 2018 to 2021,G block continuously implemented polymer microsphere profile control and flooding,and the injection pressure increased from 14.9 MPa to 17.4 MPa,with an average annual pressure increase of 0.8 MPa.Comparing the pressure drop curve,water absorption indicator curve and water absorption profile of typical wells before and after profile control and flooding,it shows that the polymer microspheres block the dominant water drive channels,improve water absorption and expand the swept volume of water drive after profile control and flooding.The monthly decline rate in the implementation area decreased from 1.25%to-0.17%,and the water cut increase rate decreased from 3.3%to 2.5%.The water drive development effect has obviously improved.
polymer microsphere profile control and floodingeffect evaluationG blockJiyuan oilfield