Fiber flushing spacer fluid for oilfield well cementation

Abstract

The invention relates to a fiber flushing spacer fluid for oilfield well cementation. The spacer fluid consists of the following raw materials in parts by weight: 100 parts of base solution, 0.2-0.4 part of anti-crack fiber and 0.4-1.0 part of petroleum sodium sulfonate, wherein the base solution consists of the following raw material components in parts by weight: 92.5 parts of clear water, 1.0-5.0 parts of water glass and 0.1-0.5 part of hydroxyethyl cellulose. The anti-crack fiber is polypropylene fiber with the length of 6-8mm or medium-alkali glass fiber with the length of 2-4mm, or a combination of the polypropylene fiber with the length of 6-8mm and the medium-alkali glass fiber with the length of 2-4mm. The water glass is liquid sodium silicate, wherein the sodium silicate accounts for 40-48 mass percent, and the modulus of the water glass is 2.2-2.6. The fiber flushing spacer fluid for oilfield well cementation has the advantages of high flushing efficiency, high adaptability and the like and is suitable for the well cementation requirements in different construction environments, the well cementation construction operation is promoted, the preparation process is simple, the product performance is stable, and the flushing efficiency is high.

Description

technical field [0001] The invention relates to a flushing spacer fluid for oil field cementing, more specifically relates to a fiber flushing spacer fluid for oil field cementing, and belongs to the field of oil field cementing technology. Background technique [0002] Petroleum is the blood of modern civilization and modern industry, and a booster for the economic and social development of countries all over the world. However, petroleum is also a non-renewable resource. Long-term exploitation and utilization have greatly reduced petroleum resources. In the face of the widening gap between the supply and demand of crude oil in my country and the depletion of domestic medium and high permeability oil and gas resources, it is particularly important to improve the utilization efficiency of oil and gas resources. The productivity of oil and gas wells mainly depends on the degree of isolation between layers, and the degree of isolation between layers depends on the sealing degr...

AI Technical Summary

Problems solved by technology

At present, the poor cementing quality of oil and gas wells is mainly caused by the low cementing quality of the cementing interface

The failure of the cementing interface sealing system will lead to the following problems: (1) interlayer channeling after the oil and gas well is put into production; (2) oil, gas and water leaking out of the pipe after cementing; (3) "sound change" in the entire annulus (4) The "sound amplitude" problem of the cementing interface

[0004] During the cementing process, if clear water is used as the flushing isolation fluid, the pressure of the static liquid column in the annular space is low, and its density and viscosity are quite different from those of mud and cement slurry, which may easily cause problems such as channeling and oil gas invasion, and cannot achieve effective isolation effect, and it is easy to lead to the collapse of the wellbore wall in the water-sensitive section of the well

In addition, with the depletion of medium and high-permeability oil and gas resources in domestic oil and gas fields, the proportion of complex oil and gas reservoirs such as deep water wells and high-temperature and high-pressure wells is gradually increasing, and conventional flushing and isolation fluids can no longer meet the quality requirements of oil and gas reservoir cementing.

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