Fracturing fluid composition for delayed crosslinking in an ultrahigh temperature environment

Abstract

The invention discloses a fracturing fluid composition for delayed crosslinking in an ultrahigh temperature environment. The fracturing fluid composition comprises a plant gum thickener, a delayed crosslinking agent, a fracturing aid and water, wherein the delayed crosslinking agent is obtained through a reaction of raw materials comprising a trivalent or more metal ester compound, glyoxal, glycerol and polyethylene polyamine. The fracturing fluid composition can form a stable, uniform and sagging fracturing fluid jelly, and the crosslinking and jelly formation time of the fracturing fluid can be delayed, and the delay time can be controlled in the range of 3-10 min. The viscosity of jelly obtained by a delayed crosslinking system at 180 DEG C or above is 100 mPas or above. The polymer use amount and the crosslinking agent use amount of the fracturing fluid composition are significantly lower than those of conventional high temperature fracturing fluid systems, so the formation damage of the fracturing fluid is greatly reduced, and the construction cost is greatly reduced.

Description

technical field [0001] The invention relates to a fracturing fluid composition, in particular to a fracturing fluid composition capable of delaying crosslinking in an ultra-high temperature environment. Background technique [0002] With the world's increasing demand for energy and the advancement of exploration technology, the exploration and development of oil and gas resources continues to develop in depth, and more and more major exploration target layers are showing a trend of comprehensive sinking. The number of abnormally high-temperature deep wells with well depths greater than 4500 m and temperatures exceeding 170 °C is increasing. The high temperature and high pressure in deep formations have brought many difficulties to oil and gas formation stimulation. [0003] A series of problems such as the lack of high-temperature-resistant fracturing fluids suitable for temperatures above 180 °C, and the incompatibility of fracturing design theory and technology for ultra-h...

AI Technical Summary

Problems solved by technology

Although organic acid esters of high-valent metal ions as crosslinking agents can theoretically meet the thermal stability requirements of the formation environment at temperatures above 180°C, the existing high-temperature fracturing fluids have insufficient temperature resistance, no delay in gel formation, and chemical agents Large amount of fracturing fluid and other problems, resulting in poor sand-carrying capacity of fracturing fluid, poor operation safety, complex equipment and high construction costs

In particular, due to the structural defects of the existing cross-linking agent, the metal ions in the cross-linking agent are released intensively in the early stage, and the metal ions cannot be released synchronously with the change of the well-entering environment, so that the fracturing fluid is transported to the bottom formation. Cross-linking has already formed before, making the pumping pressure increase

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