加重压裂液用聚合物稠化剂合成及性能

加重压裂液是解决施工压力过高的有效手段之一,普通瓜胶加重压裂液残渣含量较高、对地层伤害较大,而VES类压裂液又受到使用温度的限制,无法应用于高温井压裂施工。针对上述问题,利用水溶液聚合法合成了一种AM/CnDMAAC/NVP超分子聚合物BC40。通过对特性黏数和溶解性能的评价,结合正交实验与单因素法对聚合条件进行了优化,得到最佳聚合条件为:聚合单体总浓度为30%、引发剂浓度为0.12%,聚合温度为35℃,通氮排氧1 h,反应时间5 h。BC40在甲酸钠加重的水溶液中具有良好的增黏能力。配制不同密度的加重压裂液在120℃、170 s^-1条件下剪切2 h,表观黏度稳定在30 mPa·s以上,表现出良好的耐温耐剪切性能;向不同密度的加重压裂液中加入破胶剂,在95℃下均可破胶,得到的破胶液表面张力低,破胶后残渣含量低,对地层伤害小。

Conductometric sensor based on oxytetracycline imprinted polymer membrane

A conductometric sensor sensitive to oxytetracycline hydrochloride （OTC.HCI） was developed on the basis of utilizing OTC.HCl imprinted polymer, synthesized under the optimized conditions by using non-covalent imprinted technology with OTC.HCl as a template, MAA as a functional monomer, and EGDMA as a cross-linker, which were the composition of the sensing membrane. The responses increased linearly with the increase of OTC.HCl concentration in the range of 0.99-12.0 μM. The response mechanism of the sensor was also discussed.