Inhibitor for preventing the formation of natural gas hydrates of high-sulfur acid gas fields

Abstract

The invention relates to an inhibitor for preventing the formation of natural gas hydrate of high-sulfur acid gas fields, which comprises the following components in percentage by weight: 5 to 30 percent of biopolymer, which has the weight average molecular weight of between 3,000 and 10,000, of vinyl pyrrolidone and vinyl caprolactam or terpolymer, which has the weight average molecular weight of between 65,000 and 100,000,of the vinyl pyrrolidone, the vinyl caprolactam and N, N-(dimethylamino)ethyl methacrylate, 5 to 30 percent of amido group-containing and lipid group-containing polyesteramide or amidation product which is formed by polymerizing maleic anhydride, a derivative thereof and alkyl alcohol amine and has the number average molecular weight of between 1,000 and 15,000, 10 to 15 percent of surfactant and defoaming agent, and 50 to 70 percent of mixture of methanol or ethanol and glycol. The inhibitor has better inhibition effect on acid natural gas hydrate which has the H2S content between 0 and 8 percent, the CO2 content between 0 and 5 percent, and no hydrocarbon components above C2.

Description

technical field [0001] The invention relates to an inhibitor used for preventing the formation or accumulation of hydrates in the exploitation of acidic natural gas containing high hydrogen sulfide and in the process of ground gathering and transportation. Background technique [0002] In the process of natural gas exploitation and ground gathering and transportation, with the change of ambient temperature and working conditions of gathering and transportation (temperature, pressure and flow state), hydrocarbons such as methane and ethane and acidic compounds such as hydrogen sulfide and carbon dioxide in natural gas Separation of water (saturated water and liquid phase water) can easily form solid hydrates, causing downhole oil casings, gathering and transportation pipelines and surface equipment to be blocked, which will affect and harm the production of gas fields. Not only seriously affect the normal production of gas wells and gathering and transportation systems, but a...

AI Technical Summary

Problems solved by technology

Because the inhibitory effect of the kinetic inhibitor KHI is greatly affected by the gas composition, some KHIs that have a good inhibitory effect on type II structure hydrates have poor inhibitory effects on type I structure hydrates. , hydrogen sulfide, carbon dioxide and a small amount of ethane, no heavy hydrocarbons, mainly forming type I structure hydrates of sour natural gas gathering and transportation system, the above patented products of kinetic inhibitor (KHI) and antipolymerization agent (AA) are not fully applicable

According to the field application report (SPE 93450) of foreign low-dose hydrate inhibitors in the prevention of hydrates in sulfuric acid-containing natural gas gathering and transportation systems, the gathering and transportation systems contain a large amount of heavy hydrocarbon components such as condensate oil. Condensate oil (dry gas), sour natural gas hydrate containing high hydrogen sulfide and carbon dioxide, no application reports

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