Oil field shaft cleaning and stratum descaling de-blocking agent and preparation and application thereof

Abstract

Provided are an oil field shaft cleaning and stratum descaling de-blocking agent and preparation and application thereof. The oil field shaft cleaning and stratum descaling de-blocking agent is prepared by mixing 5-15 parts of EDTA-2Na, 1-8 parts of alpha-d-sodium glucoheptonate, 0.5-5 parts of beta-d-sodium glucoheptonate, 2-8 parts of potassium acetate, 0.5-5 parts of sodium lactate, 2-10 parts of glycol alkyl glucosamide active agent, 0.1-10 parts of enzymes, 1-6 parts of monosaccharide, 0.5-5 parts of ethyl alcohol and 28-87.4 parts of water. The oil field shaft cleaning and stratum descaling de-blocking agent is applied to shaft cleaning and stratum descaling. Active ingredients and a chelating agent are matched, an inorganic dissolution reaction is achieved mainly through a mild chelating mechanism, the product is carried out in a neutral environment from beginning to end, the synergistic effect is good, and barium sulfate, calcium sulfate, strontium sulfate and other impurities which cannot be removed through conventional acid pickling and conventional working liquid can be removed better; meanwhile, viscosity reduction and de-blocking can be achieved, part of viscosity reduction can be removed, the liquidity of crude oil can be improved, and the de-blocking efficiency is high; water sensitivity can be effectively inhibited, water blocking can be eliminated, good improving and stabilizing are achieved for stratum rock cores, oil deposit frameworks are not damaged, and oil deposit is protected well.

Description

technical field [0001] The invention relates to a formula of a safe and environment-friendly neutral plugging-removing agent, in particular to a plugging-removing agent for wellbore cleaning and formation descaling in oilfields and its preparation and application. technical background [0002] In oilfield development, the deposition of various inorganic scales in well bores, tubing and formation rocks is a serious and common problem. These scales can be deposited in tubing, perforation holes and formations, and the presence of scales will seriously affect the flow of fluids, resulting in a decline in the production of oil producing wells. There are also many reasons for the formation of scale. Generally, the scale components encountered are mainly carbonates or sulfates of calcium, magnesium, barium, and strontium. Iron is also often found. The composition and structure of scale depends on the specific conditions of the oil field. Precipitates such as barium sulfate and cal...

AI Technical Summary

Problems solved by technology

[0004] 1. Acidification is easy to form acid residue, and the aging oil and residual acid cannot be processed by reverse discharge

[0005] 2. Construction is dangerous and unsafe for people, equipment and environment

[0006] 3. After acidification, the strength of the reservoir decreases, loosening and easily causing sand production, and after plugging removal, the sand control period of the operation is often reduced

[0007] 4. The equipment string is corroded, the strength is reduced, and the service life is shortened

[0008] Due to the defects of conventional acidification, the development of neutral and non-acid technology has been developed, and the effect is also good. However, due to the invisible acid process adopted: that is, the solution test is neutral on the ground, and the acid is generated in the underground reaction, through the acid and inorganic The scale reaction mechanism is realized. After the reaction, the pH value is about 4-5 (weak acid range), and the weak acid range may cause secondary precipitation of iron ions or other related problems.

However, other plugging agents have the disadvantages of fast reaction speed, failure to reach the deep part of the reservoir, and large dosage.