油套管腐蚀速率影响因素敏感性试验研究

油管是油井生产的关键器材,井下管柱的腐蚀是油田开采过程中面临的重要问题,分析各因素对腐蚀速率的影响规律,从而提出有层次的防腐建议至关重要。结合海上油田生产实际和各种影响因素,通过自主研制的腐蚀试验装置,模拟了温度、含水率、CO₂分压、铬含量等因素对其影响程度,并利用灰色关联度的方法对各个影响因素进行了排序和分析。腐蚀损害因素的关联度排序为:温度>含水率>CO₂分压>铬含量。影响腐蚀速率最主要的因素为温度和含水率,在深度较深或者地层稳定梯度较高的井,首先应考虑管材的腐蚀,而在油田前期设计管柱材料时,要对全生命周期内的含水率进行综合考虑,以最大含水率条件为极限腐蚀情况。

Sensitivity Test of Influencing Factors on Corrosion Rate of Oil Casing

Tubing is the key equipment for oil well production. The corrosion of downhole string is an important problem in the process of oilfield exploitation. It is important to analyze the influence of various factors on the corrosion rate. Combined with the actual production and various influencing factors of offshore oilfields, the effects of temperature, water content, CO₂ partial pressure, chromium content and other factors were simulated by self-developed corrosion test equipment, and the grey correlation degree method was used to influence each influencing factor. Sorted and analyzed. The correlation degree of corrosion damage factors is: temperature>water cut> CO₂ partial pressure>chromium content. The most important factors influencing the corrosion rate are temperature and water cut. In wells with deep depth or high stratum stability gradient, the corrosion of the pipe must be considered firstly, when designing the working string material in the early stage of the oilfield, the water cut in the whole life cycle is considered comprehensively under the condition of maximum water cut as the ultimate corrosion condition.