高效络合酸体系性能评价及应用

Performance Evaluation and Application of Complex Acid System

为有效控制二次沉淀的生成,常规砂岩酸化作业一般采用前置液、处理液和后置液三段式注入工艺,作业工序相对复杂。针对这一问题,提出了单步酸化高效络合酸体系。单步岩心流动实验显示,络合酸解堵效果良好,酸化后渗透率提高至初始渗透率的1. 68倍;二次沉淀抑制性能和残酸离子浓度分析实验表明,所生成的络合物溶解性好,不易发生二次沉淀。海上油田现场9井次试验均取得良好效果。该体系能简化施工工序,明显减少施工工时,有效降低施工药剂费用。

In the conventional sandstone acidizing operation,in order to effectively control the generation of secondary precipitation,a three-stage injection process of the pre-liquid,the treatment liquid and the post-treatment liquid is generally adopted,and the operation procedure is relatively complicated.Aiming at this problem,a highly efficient complex acid system capable of one-step acidification was proposed.The one-step core flow experiment showed that the complexing acid had good deblocking effect and the acid permeability increased to 1.68 times of the initial permeability;at the same time,the secondary precipitation inhibitory and residual acid ion concentration analysis experiments showed that the generated complex had good solubility and was less prone to secondary precipitation.Good results were obtained in the 9 well tests of offshore oilfield.This system can obviously smplify construction procedures,reduce construction duration and chemical costs.