户部寨气田腐蚀规律研究

The Research of Corrosion Rule in Hubuzhai Gas Reservoir

 王选奎¹ 洪霞²

中原油田分公司采油工程技术研究院 中原石油勘探局勘察设计研究院

 　户部寨气田随着开采时间的延长,气井产出水呈上升趋势,腐蚀现象也逐渐明显。针对户部寨气田腐蚀特征,从8个方面进行了研究,研究结果表明:部分气井油管存在腐
蚀,腐蚀速度与产气压力存在正比关系;随CO₂浓度的升高,腐蚀速度逐渐增大,当CO₂浓度接近饱和时,腐蚀速度达到最大值,并维持在一定水平;随温度升高CO₂腐蚀速度增大;日产水量在0.5～2.3 m³时,油管的腐蚀速度较大,而日产水量低于0.5 m³和高于2.3 m³的气井,腐蚀速度较低;腐蚀速度随矿化度的增加而增大,但当矿化度大于35 682 mg/L,腐蚀速度随矿化度的增大而逐渐下降;油水比不同,对腐蚀产生的影响也不一样;日产气量低于5.6 ×10⁴m³/d时,产气量对腐蚀的影响较小;当产气量超过5.6×10⁴m³/d时,随产气量的增加腐蚀速度加快;介质流速增大,腐蚀速度增大。

Hubuzhai Gas Reservoir is with high buried dep th, low
permeable and compact oil & gas reservoir, well-developed
fracture, high inhomogeneous formation. Corrosion is
gradually p resented with the extension of p roduction period.
CO2 is decided to be main one among corrosion factors after
study. The research was done from eight aspects aiming at the
corrosion characters of Hubuzhai Gas Reservoir. The result of
research shows: With respect to corrosion tubing in some
wells, corrosion speed is in direct p roportion with the
p ressure of p roduction gas. Corrosion speed gets faster as the
increase of CO2 consistence and it reaches maximum,
maintains at one high level when CO2 consistence is
saturated. Higher temperature, higher corrosion speed.
Ttubing’s corrosion speed is fast as dailywater p roduction is in
0. 5 ～2. 3 m3. Normally, higher salinity, higher corrosion
speed. However, corrosion speed can go down with the
increase of salinity when salinity is above 35682 mg/L. The
ratio of oil and water can influence corrosion speed. With the
increment of gas p roduction as it is over 5. 6 ×104 m3 /d,
corrosion speed gets faster. Higher medium flowing speed,
higher corrosion speed.