A kind of soluble temporary plugging agent for acid fracturing and preparation method thereof

Abstract

The invention discloses a soluble temporary plugging agent used for acidizing fracturing, and a preparation method thereof. The soluble temporary plugging agent is mainly composed of following soluble raw materials, by weight, 60 to 90% of magnesium alloy particle, 6 to 39% of magnesium alloy sheet, and 1 to 4% of fiber. The preparation method comprises following steps: 1, magnesium powder, aluminium powder, and iron powder obtained via drying pretreatment are delivered into a smelting furnace at a certain ratio, are heated to 660 to 700 DEG C under protection by an insert gas so as to melt the magnesium powder and the aluminium powder, and are stirred to as to realize uniform mixing of iron powder in an obtained magnesium aluminium melted liquid, an obtained mixture is subjected to thermal insulation for 25 to 35min at 660 to 700 DEG C, and is subjected to casting so as to obtain a bar material, and the bar material is cooled to room temperature; 2, the magnesium alloy bar material is processed into particles and sheets; and 3, the obtained magnesium alloy particle, the magnesium alloy sheet, and fiber are mixed with a carrying fluid at a certain ratio. The soluble temporary plugging agent possesses high temperature resistance, high plugging strength, stable plugging effect, excellent dissolving controllability, and high reliability.

Description

technical field [0001] The invention relates to a temporary plugging agent used in the development of oil and gas wells, in particular to a soluble temporary plugging agent for acid fracturing and a preparation method of the temporary plugging agent. Background technique [0002] Staged fracturing is the main means of increasing production in low-permeability and ultra-low-permeability oil and gas fields. With the large-scale development of horizontal wells, various multi-stage fracturing technologies have been gradually popularized and applied. In order to form more fractures in the reservoir of oil and gas wells during fracturing, so as to increase oil and gas production, it is an important technical measure to switch from temporary plugging to acid fracturing. [0003] Temporary plugging to acid fracturing technology often requires the use of temporary plugging agents to reduce the invasion of working fluids into the reservoir, that is, temporary plugging agents are used ...

AI Technical Summary

Problems solved by technology

Polymer temporary plugging agents have low temperature resistance, and the dissolution time is not easy to control. This type of temporary plugging agent is only suitable for oil and gas wells with shallow burial depth and low bottom hole temperature, and cannot be applied to oil and gas wells with burial depths of 4000-8000 m, high-temperature deep wells with a bottom-hole temperature of 120-180°C (however, with the continuous development of oil and gas wells, high-temperature deep wells have become the development direction of oil and gas wells), that is, their application range is limited

Although inorganic salt temporary plugging agents are suitable for acid fracturing operations in high-temperature deep wells due to their high temperature resistance, their plugging performance is poor, not stable and reliable, and will not only affect the effect of acid fracturing, but also cause damage to the reservoir. Big damage, poor practicality