Density adjustable type composite weighted fracturing fluid

Abstract

The invention discloses density adjustable type composite weighted fracturing fluid. The density adjustable type composite weighted fracturing fluid is prepared from the following components in percentage by mass: 0.25-1.0% of thickening agent, 0.2-0.6% of clay stabilizer, 0.2-0.6% of cleanup agent, 0.2-0.6% of foaming agent, 0.1-0.5% of temperature stabilizer, 0.03-0.3% of PH regulator, 0.05-0.5% of sterilizing agent, 0.3-1.0% of crosslinking agent, 1-80% of weighting agent and the balance of water, wherein the weighting agent is one of or a mixture of two of sodium chloride, potassium chloride, sodium bromide and potassium bromide. The density adjustable type composite weighted fracturing fluid disclosed by the invention can be applied to the fracturing construction of deep well compact oil and gas reservoirs and is capable of effectively achieving the purposes of reducing construction pressure, thus a ground pressure-bearing manifold can be protected.

Description

technical field [0001] The invention relates to a density-adjustable compound weighted fracturing fluid used in the development of oil and gas reservoirs. The fracturing fluid system is especially a fracturing fluid system used for the reconstruction of high-pressure, ultra-deep or tight oil and gas reservoirs. Background technique [0002] With the increasing demand for energy in the national economy, oil and gas exploration and development are developing towards deep and low-permeability layers. As we all know, the development of deep wells and low-permeability reservoirs is inseparable from fracturing stimulation. For deep wells and tight oil and gas reservoirs, the ultra-high formation fracture pressure is one of the biggest bottleneck problems in the implementation of sand fracturing. Deep wells with high fracture pressure Layer construction often causes the wellhead pressure to exceed the pressure bearing capacity of the surface pumping equipment. [0003] In order to...

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Problems solved by technology

Although the traditional use of insoluble solid particles can effectively increase the pressure of the liquid column, the flowback is insufficient or even unable to discharge the contaminated formation, and it increases the construction risk and easily causes transient high pressure and other situations.

[0004] Increase the weight of the fracturing fluid without affecting the performance of the fracturing fluid. Since the crosslinking environment of the commonly used thickeners is mostly alkaline conditions, if alkali metal salts and alkaline salts are used, hydroxide precipitation will occur , and a large amount of alkaline salt makes the solution more alkaline, although the thickener can be well dispersed, it cannot be hydrated and thickened

Therefore, sodium bromide and potassium bromide are generally selected as weighting materials, and the cost of these two salts is relatively high

[0005] At present, the use of weighted fracturing fluids has also appeared one after another in China, but domestic research on weighted fracturing fluids has just started, so research on weighted fracturing fluids needs to be further developed

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