Temporary plugging diversion agent for refracturing of oil-water well and preparation method thereof

Abstract

The invention relates to a temporary plugging diversion agent for refracturing of an oil-water well and a preparation method thereof. The temporary plugging diversion agent comprises the following raw materials: adhesive bonding agent 35-65%, plasticizer 15-25%, thickening agent 10-20%, and dispersant 10-20% calculated by the total weight of the temporary plugging diversion agent. The invention also provides the preparation method of the temporary plugging diversion agent, which comprises the following steps: preparing partial thickening agent into a thickening agent water solution; dissolving the adhesive bonding agent into the thickening agent water solution; holding constant temperature in a 25-35 DEG C water bath for 2-5 hours, and after the adhesive bonding agent is swollen completely, increasing the temperature to 45-55 DEG, and continuing holding constant temperature for 0.5-2 hours; after the adhesive bonding agent is completely dissolved, adding dispersant and stirring to be homogenous, and adding the plasticizer and the rest thickening agent while stirring to obtain viscous paste; and cutting the viscous paste to granules of side length 3-6 mm, and drying to obtain the temporary plugging diversion agent. The temporary plugging diversion agent provided by the invention has the advantages of good oil solubility and water solubility, low residue content, good elasticity, and on the like.

Description

technical field [0001] The invention relates to a diverting agent for oil well water plugging and a preparation method thereof, in particular to a temporary plugging diverting agent for repeated fracturing of oil-water wells and a preparation method thereof, belonging to the field of chemical products for oil and gas field development. Background technique [0002] Refracturing, as a technical measure for the comprehensive management of old oil and water wells (oil wells and water injection wells), is a major problem that oilfields face urgently to be solved. According to research and experiments at home and abroad, appropriate refracturing for such old wells can continue to achieve a relatively large increase in production or injection. [0003] Extending the original fractures was a common concept of refracturing before. However, this kind of refracturing has a short production stabilization period after fracturing and unsatisfactory production stimulation effects. The in...

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Problems solved by technology

[0006] (1) There are several types of plugging balls, such as plastic balls, rubber balls, and nylon balls, which have high plugging strength and small deformation; but their disadvantages are that they are easy to fall off and the plugging effect is poor. Especially because it cannot be dissolved, it is difficult to remove the blockage, which increases the risk of construction.

[0007] (2) The wax ball is mainly a mixture of paraffin, high-pressure polyethylene, barite and other components, which is characterized by small particle size and can enter perforation holes and even near wellbore areas; however, its breakthrough pressure is low, easy to deform, and has good plugging effect Poor, resulting in a large amount of use, and because most components have poor solubility with formation fluids, it takes a long time to unblock and poor applicability

However, the temporary plugging agents involved in these two patents have many shortcomings in terms of solubility and residue content, which restrict their popularization and application. The shortcomings are:

[0009] 1. Basically insoluble in oil, if the formation fluid contains more oil but less water or the fracturing fluid reduces the gel breaking fluid due to large fluid loss, the insoluble part of the temporary plugging agent will cause new blockage to the formation and seriously weaken the repeated fracturing Due to the fracture stimulation effect, the formation fluid and fracturing fluid filtration loss must be re-evaluated in the preparation of the construction plan, which increases the difficulty of the plan design;

[0010] 2. High residue content. Since the vegetable gum used is kale powder or hydroxymethyl starch or guar gum, compared with hydroxypropyl guar gum, a common thickener for fracturing fluids, the residue content is 50%-300% higher , will bring greater residue damage to the formation;

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