Nano-micron material composite profile control and plugging agent

Abstract

The invention relates to a nano-micron material composite profile control and plugging agent. The nano-micron material composite profile control and plugging agent comprises the following components:3 to 4 percent of a thickening cross-linking agent, 4 to 7 percent of an activating agent, 0.05 to 0.15 percent of a gel breaker, 0.3 to 1.2 percent of fluid loss agent, 0.05 to 0.13 percent of a ph value regulating agent, 0.5 to 1.5 percent of an antioxidant, 0.05 to 0.10 percent of a sterilizing agent and the balance of water. The thickening cross-linking agent is nano-micron grade rice hull powder which is subjected to special treatment or a mixture of the nano-micron grade rice hull powder and polyethyleneimine; the activating agent is an organic acid; the gel breaker is ammonium persulphate, sodium persulphate or a mixture of the ammonium persulphate and the sodium persulphate; the fluid loss agent is modified starch MS-5; the ph value regulating agent is a mixture of sodium carbonateand fumaric acid; the antioxidant is sodium pyrosulfite; and the sterilizing agent is formaldehyde or pentadiol. The nano-micron material composite profile control and plugging agent provided by theinvention has a certain strength and toughness, can stretch and retract and can draw and deform under certain conditions, and has a certain plugging effect on a high-permeability channel in a stratumto cause the steering of subsequent displacement flow, so that subsequent injection water enters a low-permeability layer to achieve a displacement effect on a non-spread area or the area with low spreading degree in a medium-and-low permeability layer and can achieve very good profile controlling and plugging effects.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to the field of oil and gas field chemistry, in particular to a nano-micron material composite profile control and water shutoff agent. Background technique [0002] The problem of water output from oil wells is common in the process of oilfield development, and it is necessary to implement water shutoff in production wells and adjust the water absorption profile of water injection wells. Especially in the late stage of polymer flooding, the polymer is seriously channeled near the small pores, and a large amount of polymer and water flow into the production well through the large pores, resulting in the failure of polymer flooding, and about 50% of the crude oil remains underground after polymer flooding . Therefore, to further improve the recovery rate, it is necessary to carry out plugging control in deep reservoirs to solve the phenomenon of channeling and ...

AI Technical Summary

Problems solved by technology

The nano-silica prepared by the dry method has high purity and good performance, but the equipment investment is large, the energy consumption in the production process is high, and the cost is high, so it is not often used. At present, the wet method is mostly used to prepare nano-silica at home and abroad.

However, these methods consume a lot of energy and cost, and most of them have certain pollution. With the development of profile control and water shutoff agent technology, the technology should also be environmentally friendly, pollution-free, low cost, strong profile control and water shutoff ability, and good compatibility. , less reservoir damage, better thermal stability and shear stability

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