High-temperature-resistant salt-resistant water loss reducer and preparation method and application thereof

Abstract

The invention relates to a high-temperature-resistant salt-resistant water loss reducer and a preparation method thereof in the field of oil-gas well cementation. The high-temperature-resistant salt-resistant water loss reducer includes 100 parts by weight of water, 40-80 parts by weight of 2-acrylamido-2-methyl propanesulfonic acid, 30-70 parts by weight of N,N-dimethyl acrylamide, 1-30 parts byweight of 3-allyloxy-2-hydroxy-1-propanesulfonic acid, 1-20 parts by weight of acrylic acid, and 1-20 parts by weight of acrylonitrile. The high-temperature-resistant salt-resistant water loss reducercan be cooperatively used with other oil well cement additives under a condition of the temperature of up to 180 DEG C, has a wide range of temperature application and good salt resistance effect, does not affect the performance of cement slurry in saturated or semi-saturated brine, can be cooperatively used together with matched dispersants, medium-temperature retarders and high temperature retarders and the like to prepare low water loss cement slurry meeting different well cementing requirements, and is suitable for API oil well cement at all levels.

Description

technical field [0001] The invention relates to an additive in the field of oil and gas well cementing, and more specifically, to a high-temperature, salt-resistant, and fluid-loss-reducing agent as well as a preparation method and application thereof. Background technique [0002] During the drilling process of oil and gas, every well needs to be cemented. In the cementing project, it is necessary to run the casing into the specified well depth, and then pump cement slurry into the annular space between the casing and the wellbore to balance the formation pressure, isolate the oil, gas and water layers, and support the casing. During the contact between the cement slurry and the formation and the solidification of the cement slurry, the water in the cement slurry will seep into the formation. If the water loss of the cement slurry is too large, the volume of the water phase will continue to decrease, and in severe cases, the cement slurry will not be able to be pumped. , a...

AI Technical Summary

Problems solved by technology

Polyvinyl alcohol has poor high temperature resistance, and the general applicable temperature is below 95°C

The cellulose-based fluid loss reducer will thicken the cement slurry under the condition of meeting the control of fluid loss, resulting in difficulty in construction

However, under high temperature and high pressure conditions, the amide group in the molecule of the AMPS type fluid loss reducer will accelerate the hydrolysis in the alkaline cement slurry, increase the carboxyl group in the adsorption group in the molecular structure, and cause excessive retardation of the cement slurry The phenomenon

Under high temperature conditions, the hydrolysis of the AMPS type fluid loss reducer and the desorption of the groups will directly cause the water loss of the high temperature oil well cement slurry to exceed the standard requirements, and the high temperature resistance is poor.

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