Multifunctional treating agent for natural gas hydrate drilling fluid in sea area as well as preparation method and application of multifunctional treating agent

Abstract

The invention provides a multifunctional treating agent for natural gas hydrate drilling fluid in sea areas as well as a preparation method and application of the multifunctional treating agent. The multifunctional treating agent disclosed by the invention is prepared from the following raw materials in parts by mass: 0.1 to 10 parts of modified cellulose, 2 to 8 parts of dimethyl diallyl ammonium chloride (DMDAAC), 10 to 20 parts of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and 0.02 to 0.08 part of an initiator, the modified cellulose is cellulose modified by dimethoxy methyl vinyl silane. The multifunctional treating agent for the natural gas hydrate drilling fluid can effectively inhibit hydrate decomposition, improve the low-temperature filtration property of the drilling fluid, improve the stability of a hydrate reservoir and a wellbore and guarantee safe and smooth proceeding of hydrate drilling engineering; and the paint has salt resistance, and is environment-friendly and safe.

Description

technical field [0001] The invention relates to a multifunctional treatment agent for marine natural gas hydrate drilling fluid, a preparation method and application thereof, and belongs to the technical field of marine natural gas hydrate drilling water-based drilling fluid organic additives. Background technique [0002] Natural gas hydrate reserves are abundant and have great potential for exploitation, which is of great strategic significance for alleviating the contradiction between oil and gas supply and demand in my country and ensuring energy security. Therefore, the commercial exploitation of hydrates has become an imminent scramble for high ground in various countries, and safety and efficiency are also the primary prerequisites for hydrate exploitation. However, in the process of deepwater drilling, the hydrate formation is buried shallowly, weakly cemented, and has a high risk of leakage, and gas hydrate is easily decomposed under the action of drilling fluid, wh...

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Problems solved by technology

Chinese patent document CN113773440A discloses a dual-effect treatment agent with both hydrate decomposition inhibition and fluid loss control performance and its preparation method, but the N-vinylpyrrolidone of the inhibitor is highly toxic and does not meet the requirements of offshore drilling operations. Drilling fluid environmental protection requirements; and the minimum fluid loss of the inhibitor is about 12ml, and the fluid loss performance still needs to be improved

However, the poly-3-methylene-2-pyrrolidone and poly-N-vinylpyrrolidone used are difficult to degrade and damage the marine ecological environment; the effect of the obtained inhibitor needs to be improved; and it only has the effect of inhibiting the decomposition of natural gas hydrate, without the performance of reducing fluid loss. Single function

In general, the existing natural gas hydrate decomposition inhibitors are not good in reducing fluid loss and inhibiting the decomposition of natural gas hydrate. The development of hydrate decomposition inhibitors with good performance in reducing fluid loss and inhibiting hydrate decomposition It is of great significance to maintain the stability of the wellbore and ensure safe and smooth drilling during the drilling process.

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