油井结蜡影响因素及电加热管柱下入深度优化

Influencing Factors of Oil Well Wax Plugging and Optimization of Electric Heating Pipe Column Penetration Depth

渤海JX油田2D井区原油具有含蜡量较高的特点,6口采油井长期受结蜡问题困扰,油井均不能正常生产,产能和流压波动大,生产时率低,采油速度和采出程度均较低,开发效果较差,有必要开展油井井筒结蜡影响因素及治理对策研究。通过井筒垢样检测和与相邻区块对比分析,蜡质质量分数高是井筒易结蜡的内在因素,而油井产液量低、井斜大是井筒堵塞的直接诱因。为更准确地研究产液速度和井斜对实际油井结蜡的影响规律,创新引入油藏和井筒耦合的数值模拟技术,分别得出了不同油井产液量和井斜下的井筒流体温度剖面。根据井筒流体温度剖面研究结果,提出了更换电加热管柱防蜡对策,并开展井筒电加热管柱下入深度优化研究,实现全井筒流体温度高于析蜡点,从而起到防蜡的效果。该技术应用到JX油田2D井区结蜡井治理研究后,有效地指导了现场工艺实施,油井生产时率由50%提高到95%以上。

The crude oil in the 2 D well area of Bohai JX Oilfield has high wax content.The 6 oil production wells have been troubled by waxing problems for a long time,and the oil wells cannot produce normally.The production capacity and flow pressure fluctuate greatly,the production rate is low,the oil production rate and production degree is relatively low,and the development effect is poor.So it is necessary to carry out research on influencing factors of oil well wellbore waxing and treatment countermeasures.The wellbore dirt sample detection and comparative analysis with adjacent blocks show that high wax content is an inherent factor in the wellbore that is prone to wax formation,while low oil production and large well deviation are the direct causes of wellbore blockage.In order to study the influence of fluid production rate and well deflection on wellbore waxing,innovative numerical simulation techniques of integrated reservoir and wellbore were introduced,and the wellbore fluid temperature profiles under different well production volumes and well deflections were obtained.According to the research results of the temperature profile of the wellbore fluid,the anti-wax countermeasures including using the electric heating pipe string and the optimization of the running depth of the electric heating pipe string were carried out to achieve the effect of preventing the wax formation through making the whole wellbore temperature higher than the wax precipitation point.After using this technology in oil well wax plugging treatment in 2 D well area of JX oilfield,the production rate of oil well was increased from 50%to more than 95%.