砂岩储层用多氢酸的表征分析方法研究及性能测定

Study on characterization analysis method and performance measurement of polyhydric acid for sandstone reservoir

针对常规土酸酸化导致酸岩反应过快及二次沉淀等问题,室内以三氯化磷、丙酮等为原料合成了异丙烯磷酸单体,异丙烯磷酸单体与丙烯酸通过催化剂在一定条件下合成了一种多元有机缓速酸即多氢酸。利用核磁氢谱、碳谱和磷谱检测分析氢、碳、磷元素在分子骨架的位置及连接方式,利用红外检测分析多氢酸分子官能团的结合情况,利用高效液相凝胶色谱分析多氢酸相对分子质量分布。综合样品所有测试信息,确定多氢酸的分子组成及结构,形成了多氢酸分子的表征分析方法。结果表明:所合成的多氢酸分子结构中含有异丙烯磷酸—丙烯酸共聚体。通过溶蚀性能及络合性能评价,进一步验证了多氢酸体系的缓速性能优于土酸体系,可以有效络合储层离子,抑制二次沉淀,残酸无需返排。该多氢酸体系属于环保型酸液,为油田增产稳产提供了技术支撑。

In order to solve the problems of fast reaction between acid and rock and secondary precipitation caused by the conventional mud acid acidizing,the isopropyl phosphate monomer was synthesized from phosphorus trichloride and acetone etc.in the laboratory.A kind of multi-component organic slow acid,i.e.polyhydric acid,was synthesized in the reaction of isopropyl phosphate monomer and acrylic acid through catalyst under certain conditions.The position and connection modes of three elements,including hydrogen,carbon and phosphorus in the molecular skeleton were detected by nuclear magnetic resonance spectroscopy,carbon spectrum and phosphorus spectrum.The binding of functional groups of polyhydricacid molecules was analyzed by infrared detection,and the relative molecular mass distribution of polyhydric acids was analyzed by high performance liquid gel chromatography.The molecular composition and structure of the polyhydric acid have been determined by synthesizing all the test information of the sample,and the characterization analysis method of the polyhydric acid molecule was formed.The results show that the molecular structure of synthesized polyhydric acid contains the isopropyl phosphoric acid and acrylic acid copolymer.Through the evaluation of dissolution and complexation performance,it is further verified that retarded performance of the polyhydric acid is better than that of the mud acid system,which could effectively complex the reservoir ions,inhibit the secondary precipitation,and the residual acid does not need to flowback.The polyhydric acid system belongs to the environmental-friendly protection acid,which can provide the technical support for increasing and stabilizing the production in oilfield.