Organic and inorganic composite flushing liquid as well as preparation method and applications thereof

Abstract

The invention discloses a preparation method of an organic and inorganic composite flushing liquid, and belongs to the technique of oil well cement well cementation. The flushing liquid comprises the following components: polysorbate-80, alkyl phenol polyethylene glycol ether, dodecyl benzene sulfonic acid sodium, sodium silicate, sodium pyrophosphate and water, wherein the mass ratio of each component is as follows: 20%-30% of polysorbate-80, 10%-15% of alkyl phenol polyethylene glycol ether, 5%-10% of dodecyl benzene sulfonic acid sodium, 10%-20% of sodium silicate, 5%-10% of sodium pyrophosphate and the balance of water. The flushing liquid is suitable for both the oil-based mud and water-based mud, has high flushing efficiency, improves the replacement efficiency of a well drilling liquid and cement sheath interfacial cementation quality, and can be used under the condition of 50 DEG C-200 DEG C.

Description

technical field [0001] The invention relates to an oil well cement cementing technology, in particular to an organic-inorganic composite flushing fluid for both oil-based mud and water-based mud and its preparation method and application. Background technique [0002] In cementing construction, before injecting cement slurry, it is necessary to pump a pre-fluid to separate the cement slurry from the drilling fluid. If the cement slurry comes into direct contact with the drilling fluid, the drilling fluid will "cement soak". The cement slurry is polluted by the drilling fluid to produce viscous agglomerated flocculents, which will adhere to the casing and the well wall and are not easy to replace and clean. Especially in the narrow gap when the casing is eccentric, a stagnation zone will be formed, which seriously affects the cementing quality. After the cement slurry is polluted, its fluidity will decrease, and its viscosity and dynamic shear force will increase, which wil...

AI Technical Summary

Problems solved by technology

The cement slurry is polluted by the drilling fluid to produce viscous agglomerated flocculents, which will adhere to the casing and the well wall and are not easy to replace and clean

Especially in the narrow gap when the casing is eccentric, a stagnation zone will be formed, which will seriously affect the cementing quality

After the cement slurry is polluted, its fluidity will decrease, and its viscosity and dynamic shear force will increase, which will increase the cementing pump pressure and even cause lost circulation, which will affect the normal construction of the cementing operation, and even the cement slurry will not replace the predetermined position and solidify. The compressive strength and interface bonding strength of the cement stone will be greatly reduced

[0003] At present, although there are many types of flushing fluids used in cementing mud, they all have certain limitations, such as poor compatibility with mud and cement slurry, poor temperature resistance, low flushing efficiency, weak interface cementation ability, and cannot be applied to oil wells at the same time. and water-based mud

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