Modified starch coated inhibiting and anti-collapse agent for drilling fluid and preparation method thereof

A technology of drilling fluid and anti-slump agent, which is applied to chemical instruments and methods, drilling compositions, etc., can solve the problem of increasing the thickness of the hydration film on the surface of clay particles, not hindering the hydration dispersion, and reducing the filtration loss of drilling fluid. and other problems, to achieve the effect of enhancing the coating effect, maintaining the stability of the well wall, and simple preparation method

Active Publication Date: 2019-07-05
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above-mentioned modified starch is mainly adsorbed on the surface of clay mineral particles through the amide group and (or) hydroxyl group and quaternary ammonium group in the molecule, which increases the thickness of the hydration film on the surface of clay particles and prevents the particles from colliding with each other in the drilling fluid to form large particles. , which is conducive to maintaining the content of fine particles in the drilling fluid, which is conducive to forming a thin and tough mud cake on the well wall and reducing the fluid loss of the drilling fluid. However, due to the lack of effective hydrophobic groups in the molecular chain, it cannot prevent water Hydration and dispersion caused by molecular intrusion into clay layers

Method used

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  • Modified starch coated inhibiting and anti-collapse agent for drilling fluid and preparation method thereof
  • Modified starch coated inhibiting and anti-collapse agent for drilling fluid and preparation method thereof
  • Modified starch coated inhibiting and anti-collapse agent for drilling fluid and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0050] Synthesis of Hydrophobic Monomers Containing Phenyl and Adamantyl:

[0051] Add 400mL of acetone and 90.14g of 1-hydroxyethyladamantane into a dry three-neck flask equipped with a stirrer, condenser and dropping funnel, heat in a water bath to 50°C, and vacuum for 2 hours to remove moisture. Under nitrogen protection, 0.03 g of dibutyltin dilaurate was added. 102.64 g of 3-isopropyl-dimethylbenzyl isocyanate in the dropping funnel was dropped into the three-necked flask, and reacted for 6.5 hours to obtain a light yellow oily liquid. The light yellow oily liquid was placed in water, filtered, allowed to stand to separate layers, and the oily liquid in the lower layer was taken out, and placed in an oven at 60°C until constant weight to obtain the target hydrophobic monomer.

Embodiment 2

[0053] Mix 200g of starch with 1800mL of water to obtain starch milk with a concentration of 10.0%, heat the starch milk in a water bath at 60°C; add 0.02g of α-amylase to the above-mentioned hot starch milk, continue the reaction for 6.0h and then raise the temperature to 110°C Inactivate for 1.0 h to obtain enzyme-degraded starch emulsion, dry to constant weight to obtain partially degraded starch, and set aside.

[0054] Dissolve 200g of acrylic acid in 800mL of water, add KOH solution with a concentration of 50% by mass, adjust the pH to 8.5, place it in a vacuum drying oven, and dry it to constant weight at 25°C to obtain potassium acrylate, which is ready for use.

[0055] Add 280g partially degraded starch, 56.86g acrylamide, 22.03g potassium acrylate, 1.38g gamma-(acrylamido) propyltriethoxysilane and 3300g 1,4-dioxane successively in the reactor, stir until the monomer is completely dissolved. 0.77 g of the hydrophobic monomer prepared in Example 1 was added, and nit...

Embodiment 3

[0058] Mix 150g of starch with 850mL of water to obtain starch milk with a concentration of 15.0%, heat the starch milk in a water bath at 60°C; add 0.02g of α-amylase to the above-mentioned hot starch milk, continue the reaction for 6.0h and then raise the temperature to 110°C Inactivate for 2.0 hours to obtain enzyme-degraded starch emulsion, dry to constant weight to obtain partially degraded starch, and set aside.

[0059] Dissolve 100g of methacrylic acid in 900mL of water, add KOH solution with a mass percent concentration of 50%, adjust the pH to 8.5, place it in a vacuum drying oven, and dry it to constant weight at 25°C to obtain potassium methacrylate. spare.

[0060] Add 215g partially degraded starch, 79.30g N, N-dimethylacrylamide, 24.83g potassium methacrylate, 1.98g gamma-(methacryloxy) propyltrimethoxysilane and 2893g tetrahydrofuran successively in the reactor, stir until the monomer is completely dissolved. Add 0.76 g of hydrophobic monomers, blow nitrogen ...

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Abstract

Relating to the field of oil field additives, the invention discloses a modified starch coated inhibiting and anti-collapse agent for drilling fluid and a preparation method thereof. The modified starch coated inhibiting and anti-collapse agent for drilling fluid is a natural modification product prepared from partially degraded starch, a hydrophobic monomer, alkenyl amide, potassium alkenyl carboxylate and alkenyl silane as the main raw materials by means of enzyme-catalyzed reaction and free radical polymerization reaction. The modified starch provided by the invention is an inhibitor with hydrophobic stereo groups on a molecular side chain, can be adsorbed on the surface of an easily hydrated clay mineral to change the hydrophobicity, and has strong inhibiting and anti-collapse performance, the preparation method is simple, and is easy for industrial popularization.

Description

technical field [0001] The invention relates to the field of oilfield additives, in particular to a modified starch-coated anti-slump agent for drilling fluid and a preparation method thereof. Background technique [0002] For a long time, the problem of drilling fluid inhibition, especially the wellbore stability of easily hydratable shale has been a frequently encountered problem in drilling engineering. Using chemical methods to enhance the inhibition of drilling fluid is one of the important means to improve the stability of the wellbore, that is, adding a certain amount of inhibitory anti-slump agent to the drilling fluid can stabilize the wellbore. At present, polyacrylamide potassium salt is the most commonly used inhibitory anti-slump agent for drilling fluids in easily hydratable formations. This product mainly inhibits the formation of easily hydratable clay and cuttings through the coating and adsorption of high molecular weight polymers. Scattered. However, thi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K8/035C08F251/00C08F220/56C08F220/54C08F220/06C08F230/08
CPCC08F251/00C09K8/035C09K2208/12C08F220/56C08F220/54
Inventor 褚奇杨帆王治法杨枝李涛
Owner CHINA PETROLEUM & CHEM CORP
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