Bio-enzyme gel breaker and technique for water-based guargum fracturing gel breaking with the same

Abstract

The invention relates to bio-enzyme gel breaker, in particular to formula and technique for gel breaking of water-based guargum fracturing fluid by using the bio-enzyme gel breaker. The bio-enzyme gel breaker contains the following components in percentage by weight: 10-50% of beta- mannose, 0-20% of cellulose, 0-10% of pectinase, 0-15% of glucanase, 0-10% of xanthase, 3-10% of (NH4)2SO4, 2-5% ofNaCl, 1.5-5% of ZnCL2 and 0-60% of persulfate. The fracturing fluid gel breaking technique comprises the following steps: dissolving the bio-enzyme gel breaker in borax crosslinked fluid; mixing and blending the crosslinked fluid and the guargum base fluid, crosslinking, forming jelly, and then mixing with proppant, pressing the mixture into the oil-water well until the mixture enters the fractured crack. In this way, the fracturing process is finished. The bio-enzyme gel breaker degrades the macromolecular guargum in the stratum fracturing fluid into small micromolecular sugar, and when the jelly breaks up, the proppant is left underground, the fracturing gel breaking fluid flows back, and in this way, the construction can be completed. The bio-enzyme gel breaker has good gel breaking performance, the construction process is reasonable, the viscosity of the fracturing fluid can not decrease too early, the gel of the fracturing fluid can be broken evenly and thoroughly with little residue and small harm to the stratum, and the operation is simple and convenient.

Description

technical field

[0001] The invention relates to the formulation of a biological enzyme gel breaker for water-based guar gum fracturing fluid in oilfield development and a process for using biological enzymes to break gel, specifically, using the developed biological enzyme gel breaker and the use of biological enzymes to break the gel. A gel breaking process for water-based guar gum fracturing fluid. Background technique

[0002] In order to increase the production of single well and improve the ultimate recovery rate of oilfield, oilfields often use fracturing to reform the production wells. The quality of the fracturing effect directly affects the production stimulation effect after the fracturing measures. At present, fracturing is one of the important measures to increase production in oilfields (especially low-permeability-ultra-low-permeability oilfields). The displacement pressure gradient from the reservoir to the bottom of the well is the key to increasing product...

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