岩心中有机酸的测定研究

Study on Carboxylic Acids Determination in the Rock Core

用返滴定法测定某石油管理局提供的十二口井五十个岩心样品中的总有机酸和水溶性有机酸的含量。结果表明同一油井内不同深度的有机酸含量相差不大,同一深度的不同油井内岩心的有机酸含量相差比较大。其总有机酸含量范围为0.119 1～0.212 5 mmol.g-1。岩心中水溶性有机酸含量范围为0.002 1～0.056 3 mmol.g-1。返滴定法测定部分岩心中的有机酸含量,具有萃取率高,终点易观察,结果重复性好,误差小等优点。

The determination of the total and water-based carboxylic acids content for the fitty rock core sam- ples in the 12th well by back-titration have been investigated. It is shown that there are lesser difference for the car- boxylic acid between varied deepness in the same well and larger difference for the carboxylic acid between varied wells in the same deepness. The total carboxylic acid contents in rock core are between 0. 119 1 and 0. 212 5 retool/g, the water-based carboxylic acid contents in rock core are between 0. 002 1 and 0. 056 3 mmol/g. The method of back-titration has many advantages over ＂the survey of organic acids in petroleum products＂ （ relative to the method of direct-titration）. It has high extraction rate and precision, and the titration point is easy to be found.