絮凝法快速评价砂岩地层岩样的盐度敏感性

FLOCCULATION TEST FOR QUICK EVALUATION OF SALINITY SENSIBILITY OF SANDSTONE RESERVOIR ROCK SAMPLES

本文通过不同条件下强水敏性的安丘土、弱水敏性的高岭土及无水敏性的石英砂絮凝值的测定，对絮凝法实验条件进行了优选，并对天然岩样的盐度絮凝值曲线与盐－渗透率曲线进行了比较。结果表明：采用絮凝法得到的盐度曲线与采用岩心驱替法得到的盐度曲线形态一致，临界盐度值基本相同。因此，絮凝法完全可以代替岩心驱替法评价砂岩地层岩样的盐反敏感性。采用絮凝法评价盐度敏感性可使实验测定周期由岩心驱替法的三星期左右缩短为两天，实验样品由一块直径２．５４ｃｍ、长度约５ｃｍ的岩心柱改为２ｇ左右的粉状岩样。

The time-consumptive (2 weeks to Perform a determination) core flow test has been the standard technique for evaluating the salinity sensibility of sandstone reservoir rock samples. In this paper a fast (2 hrs per a determination), permeability non-restricted technique of low sample needs-flocculation test is suggested as an alternative. Instead of critical salinity, Ser, in core flow tests,the characteristic here determined is the critical flocculation concentration, Fer, experimentally measured as critical light transmission, Icr, an average of I values over 60 min. The procedure of flocculation experiments is optimized on suspensions of finely ground samples of bentonite, kaolinite and quartz sand in NaCl solutions and standard brines. The values of Scr and Fcr measured for five reservoir core samples are practically the same.