High-temperature-resistant efficient non-polymeric sand-carrying liquid

Abstract

The invention provides a high-temperature-resistant efficient non-polymeric sand-carrying liquidwhich mainly is prepared from a surfactant, a crosslinking assistant, a high-temperature-resistant efficient stable synergist and water. The sand-carrying liquid is characterized in that by weight, the surfactant accounts for 2-8%, the crosslinking assistant accounts for 0.5-1%, the high-temperature-resistant high-efficiency stable synergist accounts for 2%-5%, and the balance is water. by adopting the high-temperature-resistant efficient non-polymeric sand-carrying liquid, the problem of low sand carrying capacity of existing sand-carrying liquid under the high-temperature use condition is effectively solved, the liquid has good shearing stability and excellent sand-carrying capacity; the liquid is multifunctional, and has the advantages of swelling prevention and difficult deterioration; the synthetic raw materials are wide in source, convenient to synthesize and simple to prepare, and special devices do not need to be added.

Description

technical field [0001] The invention relates to an auxiliary agent for downhole fracturing operations in petroleum exploitation, in particular to a high-efficiency, high-efficiency poly-free sand-carrying fluid with high temperature resistance. Background technique [0002] With the development of oil fields and the enhancement of people's awareness of environmental protection, people are aware of the damage caused by conventional acidizing operations to the formation, and sand control operations have been paid more and more attention. In the sand control process, squeeze filling and fracturing sand control have become the main processes in the field of sand control due to their good sand control effect and long validity period. The sand-carrying fluid used for sand control uses pressure to press the formation to form fractures and support it with proppant. Because of such supported fractures in the oil layer, the liquid flow channel in the oil layer near the wellbore is imp...

AI Technical Summary

Problems solved by technology

[0003] 1. After the sand-carrying fluid enters the formation, it causes water lock damage, the compatibility with the formation water is destroyed, and the residue after the gel breaks causes permeability damage;

[0004] 2. The sand-carrying liquid itself needs to add a large amount of formaldehyde due to its perishability, which brings environmental pollution problems;

[0005] 3. The poor temperature and salt resistance of the sand-carrying liquid affects the construction effect

However, with the increase of temperature, the viscosity of the surface active system in the clean polymer-free sand-carrying fluid shows a downward trend. Even if the main agent reaches a large concentration (5%), the viscosity value at high temperature is also low, and it is difficult to Meet the requirements of high temperature sand carrying performance

For example, when the surfactant system composed of quaternary ammonium salt, betaine and aliphatic tertiary amine oxide is heated up to 70°C, the viscosity of the quaternary ammonium salt and betaine is only 40mPa.s. The viscosity value of the group of tertiary amine oxides also drops rapidly, which makes the high-temperature sand-carrying efficiency of the sand-carrying liquid low

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