A temperature-resistant and salt-resistant jelly with low cross-linking agent dosage

Abstract

The invention provides a temperature-resistant and salt-resistant jelly with a low cross-linking agent dosage. The mass percentage of the jelly is composed as follows: acrylamide / 2-acrylamide-2-methylpropanesulfonic acid copolymer 0.6%-1.2% , resorcinol 0.02%~0.04%, polyethyleneimine 0.02%~0.05%, paraformaldehyde 0.02%~0.04%, alkoxysilane 0.03%~0.1%, thiourea 0.2%~0.4%, balance It is water, the sum of each component is 100%, the salinity of the water is 22.4×104 mg / L, and the content of calcium and magnesium ions is 1.3×104 mg / L. The dosage of the jelly cross-linking agent provided by the invention is not more than 0.1%, and there is no phenomenon of gel breaking after aging for 100 days under the condition of 130° C., and the performance of temperature and salt resistance is excellent.

Description

Technical field: [0001] The invention relates to a polymer plugging agent, in particular to a temperature-resistant and salt-resistant jelly with a low cross-linking agent dosage, and belongs to the technical field of oil field chemistry. Background technique: [0002] Water injection oil production is the main method for efficient development of new blocks and adjustment of old oilfields to tap potential. Due to the continuous breakthrough of injected water, edge water and bottom water, the water content of oil wells rises rapidly during the production process, and the oil production drops sharply. become the key to enhanced oil recovery. Polymer jelly has become the most widely used water blocking agent because of its low price, simple preparation and good construction effect. However, for the high-temperature and high-salt reservoirs in western my country, the reservoir temperature is as high as 130°C, and the salinity exceeds 22×10 4 mg / L, because ordinary polyacrylami...

AI Technical Summary

Problems solved by technology

Inorganic particle type plugging agent mainly refers to the plugging agent whose main component is cement, fly ash and other inorganic particles, which are injected into the formation in the form of suspension to play a plugging role. This plugging agent has the advantage of strong plugging ability , but the outstanding defect of the granular plugging agent is that the plugging of the formation is rigid, the plugging effect is not selective, and it is easy to cause damage to the entire reservoir

Moreover, relatively speaking, the construction is difficult and the operability is poor, which limits its application. It is only suitable for plugging reservoir layers with high permeability and large pores.

For the lignin / tannin-based jelly plugging agent, since the tannin and lignin molecules are rigid molecules, the jelly formed by it has strong temperature resistance, but the cross-linking agent currently used for lignin / tannin-based jelly The gels are aldehyde crosslinking agents and phenolic crosslinking agents with high concentrations (generally greater than 1%). Since the two crosslinking agents have strong toxicity, the application of such gels is not conducive to the sustainable development of oilfields.

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