The Application And Research Of The Optimal Design Method In Polymer Microgel Conformance Treatments

Profile control is short for adjustment injection profile and production profile. It means that adopting the layering water injection, oil production, layer fracturing and water plugging technology measures etc.Adjusting the water injection rate, pressure and liquid production in each reservoir in order to relieve the inter-layer contradiction and control the rising speed of water cut. Most of oilfields are developed by water flooding, the reservoir is heterogeneous, the injection water is often absorbed by high permeable layer with little thickness and the injection profile is very uneven. For playing a role in the middle and low permeable layers and improving the sweep efficiency of injection water, we must adjust the injection profile of water flooding reservoir. That is to say, high permeable zone plugging, this is profile control and oil displacement, the purpose of profile control is to adjust the injection profile of injection wells, improve the effect of water flooding, inject the chemicals to the formation with middle, high permeability or strong absorbing water capacity in order to low the permeability of middle, high permeable layers and improve the water absorbing capacity of low permeability reservoir. The main role is to adjust the injection profile and relieve the inter-layer contradiction.The water cut of most oilfields is so high through long time water-flooding, meanwhile, the plane and vertical heterogeneity of reservoir is serious, causing the injection water along the high permeability zone dashing forward the production wells, which seriously affects the development effect of water injection. In order to solve the unbalanced inter-well contradiction and give a full play to the production potential of different permeability reservoir in the same series of strata, all kinds of profile control design techniques successively appears at home and abroad, in according to the actual production needs of our oilfields, it is of great significance to improve the effect of oilfield profile control and do a complete optimization design during the process of profile control through some theoretical research and practical experience from the domestic and foreign some oilfields.Cross-linked polymer flooding is the combination of oil displacement and profile control, making use of polymer flooding and cross-linking agent to make a slow cross-linking in the formation, forming cross-linked polymer gel. The advantages of cross-linked polymer solution prior to the gel:low viscosity, good infectivity and being helpful for site operation etc. in the injection process of a large number of cross-linked polymers, the polymer solution of weak cross-linking and not cross-linking flowing in the channel will produce the effect of oil displacement like as that of polymer flooding, and then having a oil displacement function. After cross-linked polymer solution forming the gel, which has a high strength enough to block the high permeable layer, improve the resistance coefficient and residual resistance coefficient, and greatly improve the heterogeneity of reservoir with the profile control effect.Optimal design is a method to choose the best one of most design schemes with meeting the requirements of design. It bases the mathematics optimization theory as a foundation, by means of computer, according to the performance goal-the pursuit of design for establishing the objective function to seek the optimal design scheme in the premise of satisfying all the given constraint conditions. It is of important significance to improve the economic benefit and work efficiency by combining with the actual needs of oil field and reasonably using a variety of optimal design methods.In this paper, we have analyzed the overview of Xidaliya reservoir and carried out the polymer microgel conformance treatments optimal design on the DK15well group by choosing a heterogeneity model with five point well pattern and making use of numerical simulation software do the parameter sensitivity research into the water flooding, polymer flooding and cross-linking polymer flooding. In order to achieve the purpose of optimization, it is more scientific and reasonable requirement in the development plan design of polymer flooding and cross-linking agent gel. In this paper, we have used the single factor and orthogonal experiments. We can quantitatively analysis whether there is the interaction and the influence of their interactions on cross-linking and profile control among multiple factors.We can obtain the objective function equation of improving oil increment and the related dependent variables by combining the response surface method, At the same time, we can obtain the corresponding graphs and conclusions by model regression based on the relevant theoretical research of profile control and oil displacement.