冲砂洗井技术研究现状及发展趋势

Research Status and Development Trends in Sand Washing and Well Cleaning Technologies

冲砂洗井过程中,冲砂液携带地层砂上返时,受重力影响容易二次沉积,造成砂卡、砂堵。特别是深井、超深井冲砂洗井,由于井眼轨迹复杂,携砂液摩阻增大,导致施工压力升高甚至超出冲砂洗井设备的承载能力。上述情况下,常规冲砂洗井技术难以顺利实施,作业风险高,而低压漏失井由于地层压力低、易漏失,冲砂洗井作业时冲砂液漏失严重,携砂能力下降,冲砂洗井效率降低,甚至无法将砂冲出。但随着国内外冲砂洗井技术不断进步和发展,上述冲砂洗井作业难题逐步得到解决。为推动我国冲砂洗井技术的进步,从冲砂洗井工具的结构、工作原理、技术特点以及发展趋势等方面对国内外冲砂洗井技术的研究现状进行了综述,并结合我国冲砂洗井的特点,指出了国内冲砂洗井技术的发展趋势,以期促进我国冲砂洗井技术的发展。

In the process of sand washing and well cleaning,when the sand washing fluid carries the formation sand upward,the formation sand can easily be re-deposited under the influence of gravity,resulting in sand sticking and sand plugging.For deep wells and ultra-deep wells,sand washing and well cleaning face complicated wellbore trajectories,larger friction for sand-carrying fluid,and increased construction pressures,where the construction pressure can even exceed the carrying capacity of sand washing and well cleaning equipment.Thus it is difficult to smoothly implement conventional sand washing and well cleaning technologies,and the operation risk is high.Due to the low formation pressure and leak-proneness in low-pressure absorption wells,the sand washing fluid leaks seriously during sand washing and well cleaning operations,and the sand carrying capacity decreases,resulting in reduced sand washing and well cleaning efficiency and even failure to flush out the sand.The continuous improvement of sand washing and well cleaning technologies in China and abroad has effectively solved the above-mentioned difficulties in sand washing and well cleaning operations.In order to promote the sand washing and well cleaning technologies in China,the status of sand washing and well cleaning technologies in China and abroad was reviewed in terms of the structure,working principle,technical characteristics,and development trends of sand washing and well cleaning tools.Suggestions for the development trends of sand washing and well cleaning technologies in China were proposed by considering the characteristics of sand washing and well cleaning in China,so as to promote the development of sand washing and well cleaning technologies in China.