长庆油田4731B型非金属集输管道老化特性实验研究

为推广非金属复合管在油田集输油领域的应用，明确其在集输环境中的老化特性是关键问题。基于集输油现场的工程条件，针对长庆油田试用的4731B型钢丝缠绕增强复合管，以采出原油、采出水为实验介质，通过挂片实验、水压爆破实验，借助电镜扫描、拉伸测试对复合管内衬层老化行为、拉伸性能以及复合管极限承压与老化特性进行研究。结果表明:采出原油与采出水均可渗透扩散进入内衬层内部，还会发生局部深入渗透；采出原油、采出水的局部渗透速率分别可达3.4，10.6 mm/a；在某些工况下，内衬层表面产生裂纹；短时间（168 h）内的介质渗透甚至裂纹对其机械性能影响较小，而光氧老化影响显著；现场服役813 d后，复合管极限承压下降2.79%，表明复合管承压性能稳定。

Experimental study on aging characteristics of 4731B non-metal gathering pipelines in Changqing oilfield

The investigation on the aging characteristics of non-metal composite pipes in the gathering environment is a key issue to improve its application in the crude oil gathering field of oilfields.Based on the engineering conditions of crude oil gathering field,aiming at the 4731B steel wire winding reinforced composite pipe with trial use in Changqing oilfield,the aging behavior of inner lining layer,tensile property,ultimate bearing capacity and aging characteristics of the composite pipe were studied by means of SEM scanning and tensile testing through the coupon tests and the water pressure blasting tests.The results showed that both the produced crude oil and produced water could permeate and diffuse into the inner lining layer,which could permeate uniformly and locally.The local permeability rates of produced crude oil and produced water could reach 3.4 mm/a and 10.6 mm/a,respectively.The cracks appeared on the surface of inner lining under some conditions.The mechanical properties were affected insignificantly by the medium permeation in a short period of time (168 h) or even crack,while the effect of photooxidation aging was significant.The ultimate bearing capacity of the composite pipe which had been applied in the filed for 813 days in service decreased by 2.79%,which indicated that the bearing capacity of the composite pipe was stable.