Tackifier for drilling fluid and preparation method thereof

Abstract

The invention relates to a tackifier for drilling fluid and a preparation method thereof, and belongs to the technical field of synthesis of processing agents for oil-field drilling fluids. The tackifier is a net-like polymer obtained by mixing acrylamide, a sulfo-group-containing monomer A and a pyrrolidone monomer B according to the mass ratio of 10:(3-5):(0.7-1.5), adjusting the pH value of the solution, adding a cross-linking agent C, a molecular-weight adjusting agent D and an initiator and performing copolymerization crosslinking. The preparation method is simple and practicable, and short in reaction time. The obtained tackifier has good salt resistance, has the temperature resistance up to 135 DEG C, has good effects of increasing shear viscosity and reducing filter loss when being applied to drilling fluids, is capable of substantially improving the cutting carrying capability of the drilling fluids under the condition of high temperature, has the effect obviously better than a tackifier normally used on site, is widely applicable to fresh-water drilling fluids and saturated brine drilling fluids, and has relatively good application prospect.

Description

technical field [0001] The invention relates to a viscosifier for drilling fluid and a preparation method thereof, and belongs to the technical field of synthesis of treatment agents for oilfield drilling fluid. technical background [0002] In recent years, with the continuous deepening of oil and gas exploration and development, the formations encountered by drilling have become increasingly complex, such as high temperature, high salt content, salt-gypsum formations, and water-sensitive formations. Salt resistance and temperature resistance, rock carrying and stable borehole wall and other properties, which require some drilling fluid treatment agents with high temperature resistance and salt resistance to meet the requirements of preparing high-performance drilling fluids. Among them, drilling fluid viscosity enhancers It is an important class of treatment agents for drilling fluids. Under the condition of high temperature and high salinity, the viscosifier in the drill...

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Problems solved by technology

[0003] In the prior art, viscosifiers are mainly used to improve the rheology and suspension stability of drilling fluids, which can significantly increase the viscosity of drilling fluids, but the shear force is not significantly improved, especially in brine drilling fluids; the temperature resistance is average The temperature is 120°C, and the viscosity-increasing effect drops rapidly after exceeding, or even completely fails, such as biopolymer xanthan gum, 80A51, etc.

[0004] Patent 201010593450.8 discloses a drilling fluid anti-high temperature thickener and its preparation method. The mass ratio of each component is: starch: guar gum: alkaline hydroxide: epoxide: alcohol solvent = 1:0.05~ 5: 0.01~2: 0.02~6: 0~9, a large amount of organic solvent needs to be added in the preparation process, which will bring adverse effects on the environment; patent 201110184384.3 discloses a preparation method of a viscosity enhancer for drilling fluid, and the raw materials used are Acrylamide, water, initiator, sodium hydroxide, formaldehyde, sodium bisulfite, ethanol, but in the preparation process, it is necessary to use ethanol to precipitate and separate the reactants, vacuum drying, and the production process is cumbersome; patent 201010172382.8 discloses a drilling fluid The preparation method of the anti-high temperature and anti-salt thickening agent, its main component is 2-acrylamido-2-methyl propane sulfonic acid, acrylamide and acrylic acid copolymer, in the temperature of 180 ℃, more than 30% salt water slurry, rock The rolling recovery rate of cuttings is more than 90%, but there is no mention of the viscosifying effect and the recovery rate of clear water of cuttings

Patent 201310061721.9 discloses a drilling fluid viscosifier and its preparation method. It is made of non-ionic, anionic water-soluble monomers and cationic hydrophobic monomers. It has good viscosity-increasing performance at 260°C , but the shear force of the drilling fluid is low after high temperature aging, and the salt resistance performance is not mentioned

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