Shale inhibitor and preparation method thereof

Abstract

The invention discloses a shale inhibitor, which is prepared by mass percentage of raw materials: 15-35% polydimethyldiallylammonium chloride, 10-25% polyetheramine, 10-25% % oxalic acid, 15-35% choline chloride and 15-40% water. The polyamine shale inhibitor obtained by the reaction of polyetheramine, oxalic acid, polydimethyldiallylammonium chloride and choline chloride can effectively inhibit the hydration expansion of mud shale, and has low toxicity and low Ammonia odor, high thermal stability and good compatibility with other treatment agents are currently the most promising amine shale inhibitors. The experimental results show that the rolling recovery rate is above 87.6%, the volume expansion rate is lower than 11.0%, and the water loss is lower than 29.6mL.

Description

technical field

[0001] The invention relates to the field of petroleum drilling, in particular to a shale inhibitor and a preparation method thereof. Background technique

[0002] Due to the high proportion of clay contained in shale formations, it is easy to hydrate, which has a great negative impact on drilling operations. During the drilling process, there are often problems such as wellbore instability, hole diameter expansion, pipe sticking, torque and resistance increase, etc. A series of downhole complex situations have increased the difficulty of drilling. Therefore, when drilling into shale formations, the inhibition of drilling fluid to shale must be improved to minimize the occurrence of downhole complex situations. Commonly used shale inhibitors mainly include polymers, inorganic salts, asphalt and humic acids, etc. These shale inhibitors have some shortcomings, such as asphalt is not conducive to environmental protection, silicate will make the system flow Den...

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