A magnesium alloy and its sacrificial anode device and its oil casing potential anticorrosion device

Abstract

The invention discloses a magnesium alloy, a sacrificial anode device and a potential anti-corrosion device for an oil casing, comprising 68 to 69.5 wt % of magnesium, 17 to 19 wt % of manganese, 9 to 10.5 wt % of calcium, 2.5 to 3.7 wt % % by weight of boron, 1.5 to 2.8% by weight of tin, and the rest are magnesium and impurities generated in the preparation process; the magnesium alloy electrode in the present invention has lower potential, more stable voltage, larger capacitance, more sufficient current, and energy It has the characteristics of higher density, stronger discharge activity, higher current efficiency, stronger electrochemical action, higher specific strength and specific stiffness, and better corrosion resistance; it achieves the purpose of high efficiency, durability and environmental protection, and achieves the price Low cost, reliable performance and cost-effective requirements.

Description

technical field [0001] The invention relates to the technical field of petroleum exploitation, in particular to a magnesium alloy, a sacrificial anode device and a potential anticorrosion device for an oil casing. Background technique [0002] In the process of oil and gas drilling and production, metal corrosion is a common phenomenon, and the severity of the corrosion directly affects the recovery of oil and gas. Among them, the typical oil and casing corrosion phenomena are the most representative. Once the oil and casing are corroded and damaged, the operation cycle will be shortened, the operation will be frequent, and the production cost will be increased; in severe cases, the oil and water wells will be scrapped; it will cause huge economic losses to the oil field. [0003] Most of the underground oil and casing are made of steel and are immersed in electrolyte solutions such as groundwater or well fluid (because the groundwater or well fluid has a relatively high sal...

AI Technical Summary

Problems solved by technology

Although the above-mentioned tools have certain anti-corrosion protection functions, they also have major deficiencies, mainly as follows: high electrode potential (compared to copper sulfate reference electrode), low discharge voltage, weak discharge activity, and unstable voltage; effective Low capacitance, low energy density, short service life; low current efficiency, poor electrochemical action; poor corrosion resistance, serious self-corrosion; low material specific strength and specific stiffness, easy to damage; nickel-containing , copper, chromium, zinc and other heavy metal elements, which affect environmental safety; in addition, the existing oil casing anti-corrosion methods often set sacrificial anodes on the surface of the oil casing, and weaken the oil casing corrosion by making the sacrificial anode corrode the goal of

However, since the depth of the oil well generally reaches 1,000 to 2,000 meters, or even deeper, the sacrificial anode set on the oil casing is often bumped by the well wall during the descent or ascent, causing damage and failing to prevent corrosion. effect, and because the sacrificial anode will become thinner under long-term corrosion, and at the same time, the connection with the oil casing will become loose, resulting in a decrease in the anti-corrosion performance of the sacrificial anode tube

For example, although the sacrificial anode device is arranged on the outer wall of the oil pipe in the oil pipe and deep well pump anti-corrosion and anti-scaling protector with the publication number CN204163644U, the sacrificial anode device is not fixedly arranged, so that the sacrificial anode device may break during use. Another example is that the pumping well applied current anti-corrosion device with the publication number CN107313721A is set as an anti-corrosion device outside the well, which is essentially different from the present application.

[0005] In order to solve the above problems, the present invention provides a magnesium alloy and its sacrificial anode and its oil casing potential anticorrosion device to solve the problems of short service life and poor use effect of the previous sacrificial anode materials

Images