三元复合体系NaCl代替部分NaOH对注采设备的腐蚀研究

Study on corrosion of injection and production equipment by substitutionof NaCl for partial NaOH in ASP system

为了解决在强碱三元复合驱矿场试验中高质量分数的强碱引起了地层堵塞及地面举升系统结垢等问题,开展了用Na Cl取代三元复合体系中部分NaOH的研究。在不影响驱油效果的前提下,取NaOH和NaCl质量分数之和为1.2%,评价NaOH质量分数降低、NaCl质量分数升高时的三元复合体系对7种注采设备的腐蚀程度。实验结果表明,将N80试片、J55试片和45号钢试片浸泡相同时间,含NaCl的溶液比不含NaCl的NaOH溶液腐蚀速率大,但腐蚀速率随时间增长而降低;NaCl和NaOH对分注工具节流芯的腐蚀影响区别不大;NaCl对螺杆泵转子和钨合金抽油杆的腐蚀影响大于NaOH,对螺杆泵橡胶的腐蚀影响区别不大,三者在外观上均无明显变化。实验结果认可了NaCl取代三元复合体系中部分NaOH的其他相关研究提供腐蚀研究方面的技术支持。

Study on substitution of NaCl for partial NaOH in ASP system was carried out in order to solve the problems of formation plugging and scaling of surface lifting system caused by alkali with a high mass fraction in alkali ASP flooding tests.On the premise of not affecting the displacement effect and taking the sum of mass fraction of NaOH and NaCl as 1.2%,the corrosion degree on 7 kinds of injection and production equipment in ASP system was evaluated when reducing the mass fraction of NaOH and increasing the mass fraction of NaCl.The experiment results prove that if N80 test piece,J55 test piece and 45#steel test piece are soaked for the same duration,the corrosion rate of the solution containing NaCl is higher than that of the NaOH solution without NaCl,but the corrosion rate will be reduced as the time prolonged;there is little difference between corrosive influence of NaCl and NaOH on throttling cores of the separate injection tools;the corrosive influence of NaCl on rotors of screw pumps and tungsten alloy sucker rods is bigger than that of NaOH;the difference between the corrosive influence on rubbers of screw pumps is small;and no obvious change can be found in appearance of these three materials.Experimental results recognize the technical support for relevant corrosion research on substitution of NaCl for partial NaOH in ASP flooding system.