Cross-linked polymer gel and preparation method thereof

Abstract

The invention provides cross-linked polymer gel and a preparation method thereof. The cross-linked polymer gel is coupled by a cross-linked polymer and a cross-linking agent; and by the joint action of the cross-linked polymer and the cross-linking agent, the joint of acid liquor is realized under the normal temperature. The cross-linked polymer gel has better temperature stability and cut-resistant property, thus realizing the lower filtering loss of the acid liquor and the reaction speed of acid rocks under the reservoir stratum condition and improving the acid-fracturing effect and the economic effect. The invention conducts a test according to the industrial standard SY / T5764-1995, SY / T6214-1996 by the fracture and acidification research center of oil extraction technique research institute of China Petroleum Shengli Oil Field Company Limited, and the test result displays that all indexes achieve the industrial standard.

Description

Technical field: [0001] The invention belongs to the field of high-molecular polymers, and particularly relates to a ground normal-temperature cross-linked polymer jelly body used for carrying sand in acid fracturing and a preparation method thereof. The cross-linked polymer jelly body is composed of a cross-linked polymer and a cross-linking agent coupled. Background technique: [0002] The eastern and western oil regions of my country have made great progress in the exploration and development of carbonate reservoirs in recent years, especially in the Tahe and Tazhong ultra-deep carbonate reservoirs in the Tarim Basin through acid fracturing. Good oil and gas exploration effect. Due to the well-developed pores and fractures of carbonate reservoirs and high formation temperature, to ensure the effect of acid fracturing, it is necessary to increase the penetration depth of acid fracturing fractures in the reservoir and improve the conductivity of acid-etched fractures. In th...

AI Technical Summary

Problems solved by technology

[0003] At present, the commonly used working fluid systems for acid fracturing in this type of oilfield are mainly gelling acid, emulsifying acid, and surfactant retarding acid. There is a large gap between fluid loss and acid-rock reaction speed; although emulsified acid has good retarding performance due to its special system structure, its viscosity is low (generally within 70mPa.s), and its temperature resistance Poor, under the condition of 90 ℃, its viscosity is often not more than 20mPa.s, and the fluid loss of liquid is not easy to control, especially the injection friction of emulsified acid is high, which is about 1.0-1.5 times that of clear water, which is the best quality of gelling acid. About 3-4 times, which is a fatal flaw for the construction of ultra-deep wells

The rheology and temperature resistance of the surfactant retarding acid are not ideal, generally the performance index is already poor at 90°C, and it is difficult to play a good role in increasing retardation and reducing filtration.

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