High-temperature spacer fluid suspension stabilizer for well cementation, preparation method of high-temperature spacer fluid suspension stabilizer and application of high-temperature spacer fluid suspension stabilizer

Abstract

The invention provides a high-temperature spacer fluid suspension stabilizer for well cementation, a preparation method of the high-temperature spacer fluid suspension stabilizer and application of the high-temperature spacer fluid suspension stabilizer. The high-temperature spacer fluid suspension stabilizer for well cementation comprises the following ingredients in part by weight: 58-85 parts of clay substances, 8-20 parts of welan gum, 0-5 parts of xanthan gum, 5-10 parts of inorganic salt and 2-8 parts of high-molecular polymer. The high-molecular polymer comprises one or more than one of polyvinyl alcohol, hydroxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl starch ether. The suspension stabilizer serves as an additive and is added into spacer fluid; and after being added with the suspension stabilizer, the spacer fluid has high suspension stability, high consistency, high rheological property and high resistance to elevated temperature.

Description

technical field [0001] The invention relates to a high-temperature spacer fluid suspension stabilizer for cementing, a preparation method and application thereof, and belongs to the technical field of oilfield cementing spacer fluid. Background technique [0002] In oilfield cementing operations, drilling fluid and cement slurry are often incompatible. If the two are in direct contact, the fluid in the mixing section of the contact surface will thicken and flocculate, the fluid rheological properties will deteriorate, and the fluid friction and displacement will be reduced. The water conservancy parameters such as the return speed and the return speed will change accordingly, thus affecting the displacement efficiency of the fluid, and the resulting high pump pressure is very easy to leak the weak formation. In addition, the flocs in the drilling fluid adhere to the well wall and casing wall to easily form a virtual mud cake, which seriously affects the cementation quality o...

AI Technical Summary

Problems solved by technology

[0007] In summary, it can be seen that the spacer suspensions in the prior art mostly use cellulose, xanthan gum and clay substances, and their composition is relatively simple.

In the cementing operation of deep and ultra-deep wells, viscosifying materials and suspension stabilizers are prone to pyrolysis or molecular chain breakage at high temperatures, which completely fail to suspend solid particles and wash away mud cakes, seriously affecting the spacer fluid. High temperature stability and displacement efficiency, serious cases will lead to well collapse or lost circulation, which will affect the quality of cementing

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