Method and device for performing on-line profile control on polymer driving oil field by applying crosslinking agent

Abstract

The invention provides a method and a device for performing on-line profile control on a polymer driving oil field by applying a crosslinking agent. A device for uniformly mixing a polymer solution and a crosslinking agent solution on line is applied; the components of the crosslinking agent solution are adjusted to consist of 1.5 to 2.5 wt percent of formaldehyde, 0.2 to 0.8 wt percent of ammonium chloride, 0.02 to 0.2 wt percent of resorcinol and the balance of water; a phenomenon that the viscosity of the polymer solution is reduced because of shearing can be effectively prevented; preferable profile control and driving control effects on an oil layer can be achieved; and furthermore, the method is easy to operate, convenient to use and transport and low in cost.

Description

technical field [0001] The invention relates to a method and a device for using a crosslinking agent in the technical field of oil and gas field development engineering to carry out on-line profile control in a polymer flooding oil field, so as to further improve the oil recovery rate of the polymer flooding oil field. Background technique [0002] In polymer flooding oil fields, due to the large well spacing, thick oil layers, many layers, and serious heterogeneity, the polymer solution escapes into the oil well along the high permeability layer, resulting in low sweep coefficient, which reduces the development effect of polymer flooding. To fundamentally solve this problem, the method of profile control and water blocking must be adopted to improve the water absorption profile and increase the water flooding sweep coefficient. The traditional profile control technology uses the method of directly pumping the profile control agent into the injection well on site. The constr...

AI Technical Summary

Problems solved by technology

[0005] However, most of the existing on-line profile control agents have complex components, high cost and poor controllability due to different purposes

On the other hand, in the online injection process, the polymer solution and the cross-linking agent solution are mainly mixed with the polymer solution and the cross-linking agent solution through a plurality of guide vanes arranged on the inner peripheral wall of the mixing drum. The viscosity of the cross-linking agent solution is quite different (the viscosity of the polymer solution is usually 100 to 200 times that of the cross-linking agent solution). When the two flow down the mixing drum, the flow rate of the polymer solution and the cross-linking agent solution Different, the two are difficult to fully and uniformly mix in the mixing drum; in addition, the polymer solution is in a turbulent state, and its flow rate is fast, and the guide vanes arranged on the inner peripheral wall of the mixing drum will have a large impact on the polymer solution and the crosslinking agent solution. The mixed solution has a certain shearing effect, and the mixed solution of the polymer solution and the crosslinking agent solution reduces the viscosity due to the shearing effect, which leads to the unsatisfactory profile control effect of the final prepared mixed solution on the oil layer

In addition, the existing online profile control injection methods still have problems such as large construction displacement and poor controllability.

Images