多氢酸与砂岩矿物反应特性实验研究

Experiment Study of Reactive Performance between Multi-hydro Acid and Sandstone Minerals

摘要:

基于酸岩溶蚀实验，通过使用ICP、19FNMR、31PNMR、XRF和XRD等技术对乏酸中含有元素和化学物质进行分析，研究多氢酸与4种砂岩黏土矿物的反应特性，并通过岩心驱替实验评价了多氢酸在高温高压条件下的酸化效果。ICP结合XRD测定结果表明，25℃时与蒙脱石、绿泥石和伊利石相比，多氢酸仅与高岭石反应产生硅胶，而在150℃时多氢酸与4种矿物都可产生硅胶；XRF和XRD结果表明，25℃时与高岭石、蒙脱石和伊利石相比，多氢酸仅与绿泥石反应生成AlF3沉淀；NMR矿物元素特征峰值测定结果也表明了150℃下的相同结果，多氢酸具有螯合特性。岩心流动模拟实验结果表明，多氢酸可提高岩心渗透率53.3%，而常规土酸使岩心渗透率减少了28%；ICP测定驱替流出物离子结果表明，多氢酸螯合了金属离子，而常规土酸产生了硅胶。

Abstract:

Based on the solubility experiments of acid-rock reaction, using ICP、19FNMR、31PNMR、XRF and XRD analytical technique to analyze the ions concentration and chemicals in spent acid and reaction-after residues so as to research reaction performance between multi-hydro acid and sandstone minerals and to evaluate the deep-penetration effect of multi-hydro acid by core flooding experiments under high temperature and high pressure. The ICP and XRD results showed with the increasing of temperature, the possibility of producing silica gel will increase, and when the temperature is up to 150℃, all the reaction between acid and 4 sorts of minerals will generate silica gel precipitation. XRF and XRD results demonstrated that 6% multi-hydro acid has a stronger solubility to sandstone minerals; and the reaction between multi-hydro acid and kaolinite, bentonite or illite can’t generate AlF3 secondary precipitation, but when reacts with chlorite, AlF3 precipitation could generate. And NMR results showed the same situation as well as multi-hydro acid has a good performance to chelate metal ions. Core flooding experiment demonstrated multi-hydro acid increased formation permeability by 53.3%, on the contrary conventional mud decreased by 28%;the result from measuring effluent of core flooding tests by ICP confirmed that multi-hydro acid chelated metal ions, and conventional mud acid formed silica gel.