Seawater-based fracturing fluid cross-linking agent, fracturing fluid and preparation method thereof

Abstract

The invention belongs to the field of oil field fracturing fluid, in particular to a seawater-based fracturing fluid cross-linking agent and a fracturing fluid and a preparation method thereof. The seawater-based fracturing fluid cross-linking agent comprises the following raw materials in parts by weight: 40-60 parts of water, 25-35 parts of alcoholamine borate, 10-15 parts of polyol, and 5-8 parts of boric acid. The seawater-based fracturing fluid cross-linking agent solves the problems of high dosage of modified guar gum (0.65%), high residue content, easy precipitation with calcium and magnesium ions, stratum pollution, discontinuous mixing and poor economic benefit existing in the prior art. The seawater-based fracturing fluid formed by the invention has the advantages of low use concentration of modified guar gum (0.4%-0.5%), no need to add additives such as temperature stabilizer and deoxidizer, good temperature resistance at 140 DEG C and easy to break gum; no alkaline pH regulator is needed, no calcium and magnesium ions are precipitated, the fracturing fluid has the characteristics of little damage to the reservoir and high cleanliness. Direct continuous mixing can be realized.

Description

Technical field [0001] The invention belongs to the field of oilfield fracturing fluids, and specifically relates to a seawater-based fracturing fluid crosslinking agent, fracturing fluid and a preparation method. Background technique [0002] Seawater-based fracturing fluid is one of the main technical means to realize the efficient exploration and development of marine low-permeability oil and gas reservoirs and improve the effect of fracturing reformation. The existing seawater-based modified guar gum fracturing fluid crosslinking agent has poor performance, and it is necessary to (1) increase the amount of thickener (over 0.65%); (2) add a large amount of temperature-resistant enhancers and oxygen scavengers; (3) ) Adding a pH regulator containing hydroxide ions or carbonate ions to improve the high temperature resistance of the fracturing fluid. This will inevitably cause too high viscosity in the fracturing fluid base tank, difficult to pump during construction, and unable...

AI Technical Summary

Problems solved by technology

The existing seawater-based modified guar gum fracturing fluid crosslinking agent has poor performance, and it is necessary to (1) increase the amount of thickener (more than 0.65%); (2) add a large amount of temperature-resistant enhancer and oxygen scavenger; (3) ) Add a pH regulator containing hydroxide ions or carbonate ions to improve the high temperature resistance of the fracturing fluid

This will inevitably cause the viscosity in the fracturing fluid base tank to be too high, and it will be difficult to pump during construction, and it will not be possible to achieve large displacement and continuous mixing construction; Calcium and magnesium ions form precipitates, which seriously pollute reservoir matrix permeability and fracture support zones; there are many types of chemical additives, which are not conducive to marine environmental protection

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