A gel breaker for recoverable fracturing fluid in oil and gas wells and using method

Abstract

The invention provides a gel breaker capable of recovering fracturing fluid for an oil and gas well and a use method of the gel breaker. The gel breaker is prepared from a mixture A and a mixture B, wherein the mass ratio of the mixture A to the mixture B is 1:(0.01-1). According to the gel breaker disclosed by the invention, the two mixtures are compounded, so that the gel breaking at low temperature is fast and the gel breaking time at high temperature can be controlled. The use method has the advantages that simplicity and convenience as well as thorough gel breaking of the fracturing fluid at the temperature of 40 to 130 DEG C can be realized, and the problem of incomplete gel breaking of a conventional oxidation gel breaker at low temperature is improved. In addition, the gel breaking can be thoroughly realized under the action of reservoir core powder with the content of carbonate being more than 0.2 percent, so that the difficult problems that conventional clean fracturing fluid only realizes gel breaking when encountering reservoir oil, gas and water, and cannot break the gel under the dry layer conditions are solved.

Description

technical field [0001] The invention relates to the field of oil and gas well fracturing fluid gel breakers, in particular to a gel breaker for recoverable fracturing fluid of oil and gas wells and a use method thereof. Background technique [0002] Fracturing fluid is one of the main methods to realize the effective development of low-permeability tight oil and gas reservoirs. When a large amount of fracturing fluid enters the formation to complete the fracture-making function, it needs to be quickly returned to the wellbore to reduce pollution and damage to the reservoir. This requires the addition of fracturing fluid breakers. [0003] Enzyme is a biological protein with high catalytic ability and good activity. When it catalyzes a reaction, its shape and structure do not change, so it can catalyze another reaction. Conventional enzyme gel breakers are a mixture of hemicellulase, cellulase, amylase and pectinase, which cannot degrade specific polymers and fail to achieve...

AI Technical Summary

Problems solved by technology

[0006] At present, with the severe situation of environmental protection production, it is necessary to reuse the flowback liquid. However, due to the complex water quality of the flowback liquid, the incompletely degraded polymer thickener and excessive peroxide breaker etc. It is very easy to cause problems such as non-stickiness in the re-mixing process, poor gel breaking effect of low-temperature reservoir fracturing fluid, and difficulty in breaking gel of surfactant fracturing fluid under dry layer conditions, resulting in the current conventional fracturing fluid gel breaker Not suitable for recyclable fracturing fluid systems

[0007] At present, more than 90% of oil fields use ammonium persulfate and ammonium persulfate capsules as breakers. The breaker is an oxidative breaker. Since the activity of the oxidant is related to temperature, generally when the reservoir temperature is lower than 49°C, the reaction Therefore, it is necessary to develop a recyclable fracturing fluid for oil and gas wells with excellent performance, controllable gel breaking time and strong construction adaptability. Agent and method of use