【作者】 周建伟；

【导师】 温凯；

【作者基本信息】 中国石油大学(北京) ， 油气储运工程， 2021， 硕士

【摘要】 在钻井过程中地层中的泥、砂等颗粒会因钻井液的携带作用而存在于井筒中,研究砂粒对水合物生成和分解的影响有重要意义。本文将使用微米级亲水SiO₂颗粒模拟地层中的颗粒。分别在去离子水、Na Cl溶液、乙二醇溶液、黄原胶（钻井液基础药剂）溶液和模拟钻井液（300ml去离子水+0.1g Na Cl+2ml乙二醇+0.2wt%黄原胶）中加入不同粒径和质量分数的亲水SiO₂颗粒探究其对甲烷水合物诱导期、平均生成速率、水合物最大生成量和平均分解速率的影响并分析其机理。研究表明:（1）在去离子水中,水合物一次生成诱导期随着亲水SiO₂颗粒粒径的增加而缩短,亲水SiO₂颗粒粒径变化对水合物二次生成诱导期影响不大;亲水SiO₂颗粒粒径变化对水合物一次生成甲烷平均消耗速率影响不大,但甲烷水合物二次生成甲烷平均消耗速率随颗粒粒径的增大而增加;亲水SiO₂颗粒粒径的增大使其对水合物生成量的抑制作用逐渐增强。（2）在Na Cl溶液中,甲烷水合物一次生成诱导期随着亲水SiO₂颗粒质量分数的增加而缩短,但亲水SiO₂颗粒质量分数变化对甲烷水合物二次生成诱导期影响不大;亲水SiO₂颗粒对甲烷水合物生成量和甲烷平均消耗速率具有抑制作用而且随着质量分数的增大抑制作用逐渐增强。（3）在乙二醇溶液中,水合物诱导期随着粒径和质量分数的增大而逐渐缩短;亲水SiO₂颗粒对甲烷水合物生成量具有抑制作用,甲烷水合物生成量随着亲水SiO₂颗粒粒径和质量分数的增加而减小;甲烷平均消耗速率随着亲水SiO₂颗粒粒径增大而减小;亲水SiO₂颗粒质量分数变化对水合物一次生成过程中甲烷平均消耗速率影响不大,但是水合物二次生成过程中甲烷平均消耗速率随着亲水SiO₂颗粒质量分数的增加而增大。（4）在模拟钻井液中,亲水SiO₂颗粒有延长甲烷水合物诱导期的作用,水合物诱导期随亲水SiO₂颗粒质量分数和粒径的增加而延长;亲水SiO₂颗粒对水合物最大生成量有促进作用,甲烷水合物最大生成量随亲水SiO₂颗粒粒径和质量分数的增大而增加;亲水SiO₂颗粒对甲烷平均消耗速率有抑制作用,甲烷平均消耗速率随亲水SiO₂颗粒粒径和质量分数的增大而减小。（5）黄原胶对甲烷水合物生成和分解过程均具有抑制作用。（6）亲水SiO₂颗粒对甲烷水合物分解有促进作用。最后,改进经典水合物生成和分解动力学模型,基于实验数据回归水合物生成和分解动力学模型中未知参数,对比模型计算值和实验值之间的误差,平均相对误差基本在20%以内。更多还原

【Abstract】 During the drilling process,particles such as mud and sand in the formation will exist in the wellbore due to the carrying effect of the drilling fluid.It is of great significance to study the influence of sand particles on the formation and decomposition of hydrates.This article will use micron-sized hydrophilic SiO₂ particles to simulate the particles in the formation.Respectively in deionized water,Na Cl solution,ethylene glycol solution,xanthan gum（basic drilling fluid agent）solution and simulated drilling fluid（300ml deionized water+0.1g Na Cl+2ml ethylene glycol+0.2wt%xanthan gum）,hydrophilic SiO₂ particles with different particle sizes and mass fractions were added to explore the effects on the induction period,average formation rate,maximum hydrate formation and average decomposition rate of methane hydrate and analyze its mechanism.Studies have shown that:（1）In deionized water,the induction period of primary hydrate formation decreases with the increase of the particle size of hydrophilic SiO₂ particles,and the change of hydrophilic SiO₂ particle size has little effect on the induction period of secondary hydrate formation;The change of hydrophilic SiO₂ particle size has little effect on the average methane consumption rate during the primary hydrate formation,but the average methane consumption rate during the secondary hydrate formation increases with the increase of particle size;The increase in the particle size of hydrophilic SiO₂ particles gradually strengthens their inhibitory effect on the formation of hydrates.（2）In Na Cl solution,the induction period of primary formation of methane hydrate shortens with the increase of the mass fraction of hydrophilic SiO₂ particles,but the change of the mass fraction of hydrophilic SiO₂ particles has little effect on the induction period of secondary formation of methane hydrate;The hydrophilic SiO₂ particles have an inhibitory effect on the formation of methane hydrate and the average consumption rate of methane,and the inhibitory effect gradually increases with the increase of the mass fraction.（3）In ethylene glycol solution,the hydrate induction period gradually shortens with the increase of particle size and mass fraction;Hydrophilic SiO₂ particles have an inhibitory effect on the formation of methane hydrate,and the formation of methane hydrate increases with hydrophilic SiO₂ particle size and mass fraction increase;The average methane consumption rate decreases with the increase of the hydrophilic SiO₂ particle size;The change in the mass fraction of hydrophilic SiO₂ particles has little effect on the average methane consumption rate during the primary formation of hydrate,but the average consumption rate of methane during the secondary formation of hydrate increases with the increase in the mass fraction of hydrophilic SiO₂ particles.（4）In the simulated drilling fluid,hydrophilic SiO₂ particles have the effect of prolonging the induction period of methane hydrate.The hydrate induction period is prolonged with the increase of the mass fraction and size of hydrophilic SiO₂ particles;Hydrophilic SiO₂ particles have the greatest effect on the formation of hydrates.The maximum formation of methane hydrate increases with the increase of the particle size and mass fraction of hydrophilic SiO₂particles;Hydrophilic SiO₂ particles have an inhibitory effect on the average consumption rate of methane,and the average methane consumption rate decreases with the increase of the particle size and mass fraction of hydrophilic SiO₂ particles.（5）Xanthan gum has an inhibitory effect on the formation and decomposition of methane hydrate.（6）Hydrophilic SiO₂ particles can promote the decomposition of methane hydrate.Finally,improve the classical hydrate formation and decomposition kinetic model,return to the unknown parameters in the hydrate formation and decomposition kinetic model based on experimental data,and compare the error between the calculated value of the model and the experimental value.The average relative error is basically within 20%.更多还原