Preparation And Performance Evaluation Of High Temperature Resistant Clay Stabilizer

In the oil production process,in order to reduce the mining cost and stabilize the oilfield production,water injection development is often used.The reservoir contains a large amount of clay minerals.When the clay minerals encounter the injected water,the volume expands and then disperses and even migrates with the injected water,blocking the reservoir pores and rock pore throats,resulting in increased water injection pressure and reducing oilfield production.In order to solve this problem,clay stabilizers are often added to stabilize reservoirs and increase oilfield production.With the further deepening of oil exploitation,the formation temperature is high and the permeability is low,which puts higher requirements on the temperature resistance and molecular design of the clay stabilizer.In this paper,a high-temperature resistant small-molecule clay stabilizer was designed through literature investigation and molecular structure analysis,that is,the introduction of quaternary amino groups on silicone molecules.The molecule not only has the advantages of multi-point adsorption(physical adsorption)of the quaternary ammonium salt type clay stabilizer,but also has the chemical adsorption property of the silicone-type clay stabilizer,and improves the water solubility and temperature resistance.In this paper,two kinds of quaternary ammonium group-containing silane coupling agent molecules were synthesized by the screening of reaction monomers and the optimization of reaction conditions,and the optimal clay stabilizer dosage and optimal compounding were optimized.The scheme also explored the mechanism of action of the new high temperature resistant clay stabilizer.Studies have shown that:?-chloropropyltriethoxysilane and trimethylamine salt synthesis of high temperature clay stabilizer ZWS-1,the optimal synthesis condition is the molar ratio of?-chloropropyltriethoxysilane to trimethylamine salt 1.1:1 The reaction temperature is90°C,the constant temperature reaction is 40 h,the potassium chloride dosage is 5wt.%;the anti-expansion rate of 4wt.%ZWS-1 at 150°C is 93.26%,and the anti-expansion rate at 300°C is 87.93%;It is 1.5 wt.%;the optimal compounding scheme is 1.5wt.%ZWS-1compounded with 4wt.%potassium chloride.?-(2,3-epoxypropoxy)propyltrim ethoxysilane(hereinafter referred to as KH560)and trimethylamine hydrochloride salt synthesis ZWS-2,the best synthesis conditions are kh560 and trimethylamine hydrochloride The molar ratio of salt is 1.1:1,the reaction temperature is 70°C,the reaction temperature is 6h,the anti-expansion rate of 4wt.%ZWS-2 at 150? is 96.26%,the anti-expansion rate is 85.39%at 300?;the optimum dosage is 1.5wt.%The optimal compounding scheme is 1.5wt.%ZWS-2 and 4wt.%potassium chloride.In order to explore the anti-swelling mechanism,a layered structural material similar to montmorillonite structure,MgAl-CO₃-LDH(hereinafter referred to as LDH),was synthesized to discuss the anti-swelling mechanism of the synthetic clay stabilizer.The results of polarized light microscopy and scanning electron microscopy showed that the LDH treated by the clay stabilizer ZWS-1 was more agglomerated than the LDH before treatment,and the state of non-horizontal stacking appeared,and the erected or slanted piled up;X-ray diffraction results showed The LDH treated by the clay stabilizer ZWS-1has a bigger spacing than the LDH layer before treatment,indicating that the reaction between the high temperature clay stabilizer ZWS-1 and LDH makes the LDH layer spacing bigler;The CO vibration peak appeared at 1121 cm^-1 in the infrared spectrum of the clay stabilizer ZWS-1,and the vibration peak disappeared in the infrared spectrum of the LDH modified with ZWS-1,and 1034 cm^-1 and 796 cm^-1 The bending vibration peaks of Si-O-Si and Si-O-Al bonds appeared,indicating that the hydroxyl groups on the surface of LDH dehydration condensation reaction with the hydroxyl groups after hydrolysis of ZWS-1 to produce chemical bonds.Therefore,the synthesized clay stabilizer has high anti-swelling property and high temperature resistance.