Delaying cross-linking polymer hard-gel in-depth profile controlling agent and preparation method thereof

Abstract

The invention relates to a delaying cross-linking polymer hard-gel in-depth profile controlling agent and a preparation method thereof. The profile controlling agent consists of the following raw materials: anionic poly aceylanide, sodium dichromate, sodium sulfite, soldium salicylate and water. The preparation method is carried out according to the following steps of: adding the required amount of anionic poly aceylanide into the required amount of water; after the anionic poly aceylanide is sufficiently dissolved, sequentially adding the required amounts of sodium dichromate, sodium sulfiteand soldium salicylate; and sufficiently stirring to obtain the delaying cross-linking polymer hard-gel in-depth profile controlling agent. The delaying cross-linking polymer hard-gel in-depth profile controlling agent and the preparation method thereof have the beneficial effects that the delaying cross-linking polymer hard-gel in-depth profile controlling agent is simple to prepare, has stable performances, is convenient to construct, has long gelling time and has strong gel strength after being gelled; the long-term and large-dose injection is realized on site; and the delaying cross-linking polymer hard-gel in-depth profile controlling agent disclosed by the invention can enter the deep position of an oil pool to block a preferential path so as to improve the waterflooding extraction effect and improve the recovery ratio of the oil pool. The delaying cross-linking polymer hard-gel in-depth profile controlling agent is applied for over 40 well times on site and has good applicationeffect.

Description

technical field [0001] The invention relates to the technical field of oilfield chemistry, and relates to a delayed crosslinking polymer strong gel deep profile control agent and a preparation method thereof. Background technique [0002] During the water injection development process of the oil field, due to the long-term erosion of the injected water and the heterogeneity of the formation, the injected water is easy to seep along the high-permeability channels, and the water channeling of the injected water occurs, resulting in a continuous decline in the sweep efficiency of the water injection, and the oil well contains water. rate rises. Ordinary profile control agents can control the injection water rushing along the high-permeability layer, but the treatment radius is small, and the effective period after the measures is relatively short. The deep profile control technology can make the profile control agent enter the deep part of the reservoir, force the subsequent i...

AI Technical Summary

Problems solved by technology

[0002] During the water injection development process of the oil field, due to the long-term scour of the injected water and the heterogeneity of the formation, the injected water is easy to seep along the high-permeability channel, and the injected water The phenomenon of water channeling leads to a continuous decline in the sweep efficiency of water injection and an increase in the water cut of oil wells

Ordinary profile control agents can control the injection water to rush along the high permeability layer, but the treatment radius is small, and the effective period after the measures is relatively short. After repeated profile control in the near-wellbore area, the effect continues to decline, and the oil saturation is greatly reduced