机采水平井低表面能防蜡技术研究与应用

RESEARCH ON LOW SURFACE ENERGY DEWAX TECHNOLOGY IN HORIZONTAL WELL AND APPLICATION

长庆油田部分水平井开发区块随着生产时间的不断延续,生产过程中井筒出现了严重的结蜡现象。为保证油井正常生产,针对水平井的结蜡特点和影响结蜡的因素提出了一种水平采油井低表面能油管防蜡技术,通过在油管内表面涂覆具有疏油疏水、光滑内涂层,形成低表面能的油管内壁,阻止蜡晶吸附,起到防蜡目的。文章基于水平井产出液对油管涂层防蜡性能的影响,通过开展不同蜡质、含水、温度、压力等条件下油管涂层的优选及适应性评价研究,制定不同工况下油管防蜡涂层选用图版,同时针对机采井开展了防蜡涂层的耐磨性评价,指导现场应用。现场试验45口井,试验后在没有采取其它清防蜡措施情况下,到目前平均生产周期已达75d,最长井达395d,尚未出现检泵作业。研究结果表明,机采水平井低表面能防蜡技术与传统清防蜡工艺相比,不需要周期性地进行清防蜡作业,可以有效降低管理风险,经济效益更好。

With the continuous production in horizontal wells at Changqing oilfield,serious waxing is observed in the wellbore during the production.In order to ensure the normal production of oil wells,according to the wax characteristics of the horizontal wells and the influencing factors,a thin hydrophobic,oil-phobic coating is added on the inside wall of the tubing to form a smooth low surface-energy internal tubing wall to prevent wax crystal adsorption.Based on the effects of horizontal well produced fluids on the performance of pipe coating,by conducting studies on different wax,water cut,temperature and pressure conditions to find the optimum coatings and evaluate the adaptability.A tubing paraffin coating selection chart is made for different working conditions.a wear evaluation is also made for the coatings to guide the field use.At present,it has been tested in 45 wells,the average production cycle has reached 75 days,and the longest one is 395 days.No pump repair has been needed.The research results show that the low surface energy dewaxing technology compared with traditional process does not need periodical dewax operations,can effectively reduce the management risk,and get better economic benefits.