High-temperature-resistant filtrate reducer for drilling fluid and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant filtrate reducer for drilling fluid. The high-temperature-resistant filtrate reducer is prepared from the following raw materials in parts by weight: 35-55 parts of synthetic resin, 15-25 parts of aldehyde ketone resin, 45-65 parts of sulfonated asphalt formed by sulfonating natural asphalt, 5-15 parts of an initiator B, 10-20 parts of nano calcium carbonate, and 60-80 parts of an alkene monomer polymer. The invention also discloses a preparation method of the high-temperature-resistant filtrate reducer. The preparation method comprises thefollowing steps: stirring the sulfonated asphalt and the alkene monomer polymer at 45-60 DEG C for 30-40 minutes; adding an initiator B, stirring the components for 2-3 hours, then adding nano calciumcarbonate, heating the mixture to 95-120 DEG C, then adding synthetic resin and aldehyde ketone resin, stirring the mixture, carrying out heat preservation reaction at 100-110 DEG C for 4-5 hours, and drying the reaction product to obtain the high-temperature-resistant filtrate reducer. The high-temperature-resistant filtrate reducer has the advantages of excellent filtration reduction performance, stronger crack plugging capability, stable mud rheological property, stable well wall and excellent high-temperature resistance and salt resistance.

Description

technical field [0001] The invention relates to the field of additives for drilling fluids, more specifically, it relates to an anti-high temperature fluid loss reducer for drilling fluids and a preparation method thereof. Background technique [0002] Fluid loss additives are chemical additives that need to be added to oilfield drilling fluids. Fluid loss additives are also called fluid loss control agents and fluid loss additives. During the drilling process, the invasion of the filtrate of the drilling fluid into the formation will cause the shale to hydrate and expand, and in severe cases, it will lead to instability of the wellbore and various downhole complications. The purpose of adding fluid loss reducer is to reduce the fluid loss of drilling fluid as much as possible by forming a low-permeability, flexible, thin and dense filter cake on the well wall, so as to ensure the stability of drilling fluid performance and reduce the harmful liquid to It is an important dr...

AI Technical Summary

Problems solved by technology

Among them, fiber products include sodium carboxymethyl cellulose, polyanionic cellulose and sodium carboxyethyl cellulose, etc. These products have excellent fluid loss reduction performance and are applicable to a wide range of systems, but they significantly increase the viscosity of drilling fluid and are expensive. Poor temperature resistance;

[0005] Humic acid products include lignite lye, sodium nitrohumate, chromium humic acid, sulfomethyl lignite, etc. These products can reduce fluid loss and viscosity at the same time, and have certain temperature resistance, but their filtrate pollutes the environment. Destroying oil and gas reservoirs, harsh production process conditions, and great physical damage to operators;

[0006] Acrylic polymers include hydrolyzed polyacrylonitrile ammonium salts, polyacrylate polymers, etc., propionate multi-polymers, etc. These products have the functions of salt resistance and thickening and shearing at the same time, thereby inhibiting shale expansion, and the process Simple, but its anti-calcium ability is weak, and its temperature resistance is poor, and its raw materials and products have sour taste;

[0007] Resin products include petroleum resin, sulfonated lignite resin, sulfonated lignin petroleum resin condensate, etc. These products have good high temperature resistance, lubricity and anti-slump properties, but their fluid loss control performance is relatively poor, and polluted environment;

[0008] Starch products include carboxymethyl starch, carboxypropyl starch, pregelatinized starch, high temperature resistant starch and modified starch, etc. These products belong to natural polymers and their derivatives, which are easy to degrade and have good environmental protection. Poor high temperature performance, complex modification process, easy to ferment and deteriorate, and cannot be used and stored for a long time

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