CO2驱油下非金属管材耐蚀性能初步评价

Preliminary evaluation for corrosion resistance of non-metallic pipes by CO2 flooding

在CO2驱油环境中,采用碳钢的集输管网中刺漏、穿孔现象频发。使用增强塑料类的非金属管道代替部分金属管道,对减轻腐蚀、降低维护成本具有重要意义。利用腐蚀浸泡实验研究了高矿化度、高CO2含量下,柔性复合管、芳胺玻璃钢管的渗透性、膨胀性、力学性能随浸泡周期的变化。结果表明,随着浸泡时间增加,2种非金属材料的渗透率、膨胀率增大,拉伸强度下降。其中芳胺玻璃钢管的渗透性大,膨胀率相对较小,拉伸强度高。柔性复合管的渗透率小,膨胀率相对较大,拉伸强度小。根据变化后的力学性能进行强度校核后,2种材料均能满足3 MPa的集输压力要求。根据实验结果,计算得到不同管线规格下的最大许用压力。

In the CO2 flooding environment,puncture occurs frequently in the gathering and transportation pipeline network composed of carbon steel pipelines.So it is of great significance to reduce corrosion and maintenance costs by using reinforced plastic non-metallic pipes instead of some metal pipes.Corrosion immersion experiments are conducted to study the changes of permeability,expansion and mechanical properties of swelling and mechanical properties of flexible composite pipes and aramid glass steel pipes under high salinity and CO2 content with immersion periods.The results show that as the immersion periods increases,the permeability and expansion rate of the two non-metallic materials increase,but the tensile strength decreases.Among them,aramid glass steel pipe has higher permeability,relatively smaller expansion rate,and higher tensile strength.The flexible composite pipe has the smaller permeability,a relatively larger expansion rate,and the smaller tensile strength.After the strength check relay on the changed mechanical properties,both materials can meet the gathering and transportation pressure requirements of 3 MPa.Based on the experimental results,the maximum allowable pressure for different pipeline specifications is calculated.