聚合物盐水泥浆缓蚀剂研究

CORROSION INHIBITORS FOR POLYMER SALT WATER DRILLING MUDS

讨论并考察了聚合物盐水泥浆对碳钢的腐蚀性。在腐蚀性最强的３％盐水聚合物泥浆中考察了专门研制的咪唑啉类缓蚀剂Ｎｍ－１的缓蚀性能，１０００ｐｐｍＮｍ－１＋１０００ｐｐｍＮａ２ＳＯ３可使Ａ３钢和２０号钢的腐蚀速率降低８０％－８７％，且不发生点蚀；１０００ｐｐｍＮｍ－１可使４０Ｃｒ钢的旋转弯曲腐蚀疲劳寿命提高到接近在淡水基浆中的腐蚀疲劳寿命（１１．４×１０４周次）。用电化学方法研究了Ｎｍ－１的缓蚀机理。简介了Ｎｍ－１在中原油田５口井、６井次现场缓蚀试验的结果。

The corrosivity of polymer salt water drilling muds to carbon steel is investigated experimentally and an inhibitor,Nm 1,is developed to protect drill pipes working in muds. It is shown that in a most corrosive 3% NaCl polymer mud at 60-80°C,the corrosion rates of steel A3 and #20 are decreased by 80-87% when 1000 ppm Nm 1 and 1000 ppm Na 2SO 3 are introduced;1000 ppm Nm 1 prologates the otating bending corrosion fatigue life of 40Cr ,a steel similar to drill pipe steel,in this mud. To the value obtained in fresh water clay mud the mechanizm of corrosion inhibition of Nm 1 is studied by electrochemical techniques. The combination Nm 1+Na 2SO 3 has been successfully tested 6 times in drilling 5 wells in Zhongyuan Oil Fields.