Thickening agent for cleaning foamed fracturing fluid and preparation method of thickening agent

Abstract

The invention discloses a thickening agent for cleaning foamed fracturing fluid and a preparation method of the thickening agent. The thickening agent comprises the following components in percentage by weight: 5-6% of N,N'-methylene bisacrylamide MBA, 15-18% of a basic functional monomer, 3-5% of a specific functional monomer, 2-3% of a cationic polymerizable amphiphilic monomer, 3-5% of a regulator, 5-10% of an ionic activating agent, 2-4% of a dissolution accelerant, 0.08-0.15% of an initiating agent, and the balance of deionized water. The preparation method of the thickening agent comprises the steps of adding the above components into a reaction kettle to perform aqueous solution multi-component copolymerization, and preparing a polymer product by virtue of a certain post-treatment process. The thickening agent disclosed by the invention has a good viscidity increasing ability, and is good in solution viscoelasticity and heat-shearing resistance; the polymer, after being used as a thickening agent for N2 and CO2 foamed fracturing fluid, has good foaming property and foam stability; and the foamed fluid itself does not need to act with a high-valence metal crosslinking agent, and greatly reduces undissolved substance residue damages caused by water sensitivity, water blocking damages and the thickening agent, so that the fracturing construction effect can be greatly improved.

Description

technical field [0001] The invention relates to the technical fields of supramolecular chemistry and oilfield chemicals, in particular to a clean foam fracturing fluid thickener for fracturing stimulation measures and a preparation method thereof. Background technique [0002] Among the proven oil and gas resources in my country, low-permeability oil and gas resources account for a relatively large proportion. The development of such oil and gas fields is of great significance to the sustainable and stable development of my country's petroleum industry in the future. However, many problems such as fluid loss, formation damage, water lock, and flowback are prone to occur during the hydraulic fracturing development process. Foam fracturing fluid, as a new type of fracturing fluid system, greatly reduces the amount of water entering the well due to the existence of its internal gas phase, thereby greatly reducing the formation damage caused by conventional water-based fracturing...

AI Technical Summary

Problems solved by technology

The advent of this thickener quickly attracted the attention of oil fields at home and abroad, and set off an upsurge in the research and application of surfactant thickeners. However, there are still several major problems in this thickener: 1. Thickener resistance The temperature capacity is poor, and the due use effect cannot be exerted in the high-temperature well section; 2. The amount of thickener used is large and the cost is too high, and the cost per cubic meter generally exceeds 2,000 RMB; 3. The gel breaking is passive and needs to be destroyed by oil and gas The dilution with formation water can passively break the gel

[0006] In view of the advantages and disadvantages of guar gum and VES fracturing fluid thickeners, the focus of research is on low cost, temperature resistance and shear resistance (non-VES fracturing fluid thickeners), low friction, low residue (non-guanidine Glue thickener) and other four main properties come up, especially for CO 2 Foam fracturing fluid thickener, with CO 2 The compatibility of saturated aqueous solution cannot be ignored, which has prompted the research on a new generation of thickeners for clean foam fracturing fluids. There are a small number of public results, and they are all limited to small samples synthesized indoors, without scaled-up production and field application

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