High-temperature sandstone oil reservoir retarded acid and preparation method thereof

Abstract

The invention provides a high-temperature sandstone oil reservoir retarded acid and a preparation method thereof. The high-temperature sandstone oil reservoir retarded acid is composed of the raw materials of cyclodextrin, sulfonic acid and ammonium fluoride with a molar ratio of 1:1-2:2-8, the balance being water. The preparation method comprises the following steps: a, recrystallized and fully dried cyclodextrin is placed in a mortar; a proper amount of a solvent is added, and the mixture is stirred into a paste; b, sulfonic acid powder is added into the paste obtained in the step a, and the mixture is ground for 1-2h, such that a uniform viscos paste is obtained; the paste is subjected to constant-temperature drying for 8-12h under a temperature of 50 DEG C in a baking oven, such that a white powdery substance is obtained, wherein the substance is a clathrate of cyclodextrin and sulfonic acid; and c, ammonium fluoride is mixed with the clathrate obtained in the step b, such that the high-temperature sandstone oil reservoir retarded acid is obtained. Compared to existing retarded acids, the high-temperature sandstone oil reservoir retarded acid provided by the invention has the characteristics of high-temperature resistance, good retardance and high corrosion capacity.

Description

technical field

[0001] The invention relates to the field of petrochemical technology, in particular to a high-temperature sandstone oil reservoir tardy acid for acidifying oil-water wells in oil field development and a preparation method thereof. Background technique

[0002] During drilling, completion and production operations, oil and water wells are extremely vulnerable to damage, such as drilling fluid filtrate invasion, water sensitivity, particle migration, etc., which seriously affect the normal production of oil fields. Acidizing operation is an effective measure to relieve reservoir damage, improve oil well production capacity and water well water absorption capacity. It uses acid liquid to remove pollutants around production wells and water injection wells, and restore or increase the permeability of formations. Soil acid acidizing is the most commonly used acidizing measure for sandstone reservoirs, which has the advantages of low cost and strong dissolution abi...