页岩气采气管线材料L360N钢的含砂冲蚀行为研究

Study on sand erosion behavior of L360N pipeline steel in shale gas production

关键词:  冲刷腐蚀  攻角  含砂量  L360N管线钢  页岩气

Key words:  erosion corrosion  impact angle  sand concentration  L360N pipeline steel  shale gas

摘要:

页岩气开采初期井口装置存在严重冲刷腐蚀,影响采气安全及经济效益。为了制定有效的防治方案,以L360N管线钢为研究对象,研究了材料在含砂冲蚀条件下的损伤行为规律。利用喷射式冲蚀实验装置,采用失重、形貌观察等方法,研究了模拟液固冲蚀条件下,含砂量和攻角对材料冲刷腐蚀损伤的影响规律。结果 表明:射流速度为8 m/s、攻角为90°、砂的质量分数为7%时,材料的损伤最大；质量分数为3%时最低,冲蚀240 min后的累积失重约是质量分数为7%时的52%；射流速度为8 m/s、砂的质量分数为5%条件下,30°攻角时损伤最大,60°攻角时损伤最小,约为最大值的48%。 

Abstract:

Silt-erosion corrosion of wellhead devices is very severe in the initial stage of production in shale gas field, which affects the safety and economic benefits of gas extraction seriously. In order to develop effective control programs and research the damage behavior of materials under sand-erosion conditions, this paper took L360N pipeline steel as target, using the methods of jet impingement erosion experiment, weight loss and morphology observation, then the influence law of sand content and angle impact on erosion corrosion damage of material under simulated liquid-solid erosion condition was studied. The results showed that the greatest mass loss was occurred at the sand concentration of 7 wt% and the lowest was occurred at 3 wt% under the conditions of 8 m/s flow velocity and 90° impact angle. The cumulative mass loss after 240 min erosion-corrosion at the sand concentration of 3 wt% was approximately 52% of the sand concentration of 7 wt%. Moreover, the severest and lightest damage occurred at the impact angle of 30° and 60° respectively under the conditions of 8 m/s jet velocity and 5 wt% sand concentration, the mass loss of the latter is about 48% of the former.