超级13Cr钢在蒸馏水和3.5 wt% NaCl含砂流体中的冲蚀实验研究

EROSION EXPERIMENT OF SUPER-13CR STEEL IN DISTILLED WATER AND 3. 5WT% NACL SOLUTION WITH SAND

大型储层改造过程中,高速含砂流体引起的冲蚀是管柱失效的重要原因之一。利用自行研制的喷射式冲蚀实验装置,以蒸馏水和3.5 wt%Na Cl为模拟溶液,对比研究了超级13Cr钢在含砂液固两相流体中的冲蚀速率随主流速度和压裂排量的变化规律。分析了Cl^-1对超级13Cr钢的冲蚀的加速作用机理。研究表明,对于89mm×6.45 mm油管压裂,当排量低于2.2 m^3/min时,Cl^-1加速超级13Cr钢冲蚀速率作用不够明显;当排量在2.2-2.75 m^3/min时,Cl^-1使得电化学腐蚀加剧,导致总的冲蚀速率急剧增加;当排量大于2.75 m^3/min时,冲蚀速率主要由冲刷流体产生及机械作用主导,Cl^-1的影响开始降低。

Erosion caused by high speed sand fluid plays an important role in the failures of tubing string for the reservoir fracturing. The erosion rate of super- 13 Cr steel were investigated by using the self- made jet experiment device in distilled water and 3. 5wt% NaC l solution containing sand. The erosion mechanism of Cl- 1was analyzed for super- 13 Cr steel. In fracturing operation of 89 mm × 6. 45 mm oil tube,the erosion rate of Cl- 1was not obvious when the displacement was less than 2. 2m3/ min,and then increased rapidly when displacement was between 2. 2- 2. 75 m3/ min. When displacement was more than2. 75 m3/ min,the mechanical erosion dominated and the effect of Cl- 1reduced.