Research On "Three Quantity" Profile Control Technology In Medium And Low Permeability Reservoir

The domestic medium-and low-permeability oilfields are mostly oilfields for water flooding development.At present,the oilfield has entered the development stage of high-water content,high-recovery reserves,and high-cost production.As an efficient and effective oil recovery method under the current low oil price environment,profile control technology has become the focus of attention in the petroleum industry.In this paper,saturated oil-filled sandstone core tube displacement experiment was used to study the influence of viscosity and water saturation on the distribution of displacement gradient of the displacement oil.The effect of the water injection multiple and the increase of displacement gradient(increment)on the recovery factor was compared.Through indoor core displacement experiments,the relationship between different blocking agent dosages(dosages)and multi-round plugging injection methods and increasing displacement pressure gradients and enhanced oil recovery was studied.The splitting rate experiment was used to optimize the type of plugging agent and evaluate the plugging.The numerical simulation method was used to study the production dynamics of anti-five-point well patterns under different plane direction coefficients(vectors),and to identify the characteristics of plugging migration blocking under different seepage conditions.The selective plugging performance and sweep performance of the plugging agent were investigated by the glass plate physical simulation experiment,and the influence of the injection speed,the injection method,and the type of injection plugging agent on the accurate entry of the plugging agent into the target layer was evaluated.The results show that the viscosity and formation water saturation of crude oil will affect the distribution of displacement pressure gradient.The higher the crude oil viscosity is,the higher the displacement pressure gradient is.The higher the water saturation is,the smaller the displacement pressure gradient between injection and production wells is;With the increase of water saturation,the displacement pressure gradient between injection and production wells will gradually decrease;with the increase of injection water multiple times,the water flooding recovery rate will increase,and at the same time,the injection multiple can remain unchanged.Increase displacement pressure gradients and significantly increase water flooding recovery.The change of injection dose of splitting agent has a significant effect on the improvement of oil recovery and displacement pressure gradient.The extent of enhanced oil recovery increases gradually with the increase of injection profile control agent and the increase of displacement gradient.The gradual increase in the amount of blocking agent can keep the pressure gradient of the drive relatively stable.The combination of gel and microspheres was used to increase the recovery rate by more than 23%.The existence of hyperosmotic strips will lead to changes in the plane direction coefficient,the lower the number of high-permeation strips in the formation,the smaller the plane orientation coefficient,and the remaining oil reserves.After the injection of plugging agent is blocked,the injection of water will cause the liquid flow to turn.When injecting the polymer microsphere blocking agent,select a high-displacement injection that is greater than 4mL/min,and select a low-displacement volume that is less than 2mL/min when injecting the frozen adhesive blocking agent.