Application of High-Temperature Corrosion Inhibitor (Alkoxy Compound of Propargyl Alcohol) in Oilfields:

Corrosion in the Oil & Gas Industry

The oil and gas industry consists of oil exploration, drilling, development, production, oil and gas gathering and transportation, oil and gas processing, storage, transportation, petroleum refining, and other links. Corrosion problems exist in every stage of production.

Anti-Corrosion Measures

There are diverse factors causing corrosion, and their effects are highly complex. In industrial production, in addition to selecting materials with excellent performance for equipment, the main anti-corrosion measures include: electrochemical protection (cathodic protection, sacrificial anode protection), coating anti-corrosion layers on equipment surfaces, and adding chemical agents (corrosion inhibitors, bactericides, scale inhibitors, etc.).

Specific Corrosion Challenges in Oilfields

With the extension of oilfield development and the continuous increase in comprehensive water cut, the produced fluids from oil wells contain CO₂, H₂S, dissolved oxygen, organic acids, and sulfates, accompanied by high salinity. These substances cause severe corrosion to oil well tubing, casing, and crude oil gathering systems. In many oilfields, corrosion perforation, deformation, and fracture of tubing and casing, as well as pipeline leaks in crude oil gathering systems, have become increasingly serious, directly affecting the normal production of oilfields.

Corrosion Inhibitors as a Solution

The protection of oil wells by adding corrosion inhibitors has been implemented abroad since the 1970s. Adding corrosion inhibitors to oil wells can protect not only tubing, casing, and downhole equipment but also gathering pipelines and surface facilities. It is a low-cost, easily implemented, and fast-acting measure.

Types of High-Performance Corrosion Inhibitors

At present, the major types of high-performance corrosion inhibitors used abroad include propargyl alcohol derivatives, organic amines, imidazolines, quaternary ammonium salts, and others.

2SY92‑1 Oil Well Corrosion Inhibitor Performance

The 2SY92‑1 oil well corrosion inhibitor used in the Zhongyuan Oilfield is formulated with synthesized alkynyl oxymethyl ammonium salts and alkynyl oxymethyl quaternary ammonium salts. It is a water-soluble, oil-dispersible, adsorption-film-forming corrosion inhibitor.

This inhibitor can effectively control the corrosion of N80 steel and AQm steel under high salinity and carbon dioxide-saturated conditions. At a concentration of 60–70%, the corrosion inhibition efficiency reaches 80%–90%.

In 28% hydrochloric acid at 90°C, with an inhibitor concentration of 0.2%, the corrosion rate is only 58 g/(m²·h), and the inhibition efficiency exceeds 99%.

Application Method

Oil well corrosion inhibition adopts impact pre-filming treatment and periodic dosing, with a concentration of 20–50%. The inhibitor is injected into the casing-tubing annulus by pump and falls to the bottom of the well under its own weight, then flows back up the tubing with the produced fluid. During this process, most of the inhibitor dissolves in the produced water and a small amount disperses in the oil. As it flows upward, the inhibitor adsorbs onto the metal surface to form a protective film, thereby providing corrosion protection.