Design And Analysis Of Automatic Cleaning Device For Drill

In recent years, with the application of drilling technology increased in the horizontal wells, deep or ultra-deep wells and large displacement wells, the costs and risks of drilling also will increase year by year. Those problems about drill pipe itself quality, reusing and repaired quality has become very important issues during the drilling process. Currently, the flaw detection, classification and repairing of drill pipe are important means in order to ensure the quality and life of drill pipe and save the drilling cost. Drill pipe clean is a important process before the flaw detection and repairing of drill pipe.In oilfield applications, high pressure water jet cleaning technology was widely used in the drill pipe cleaning because of its unique advantages of cleaning, such as good quality, fast speed, clean, low cost, easily to automate and so on. However, in the actual operation of cleaning drill pipe using high pressure water jet cleaning technology, the artificial hand cleaning using cleaning gun has some defects, for example, cleaning not thorough and inefficient, labor-intensive and waste water. The method do not only affect the accuracy of drill pipe’s flaw detection and repairing, but also severely restrict the development of clean technology in the oil industry. In the view of above problems, while combined with drilling process characteristics and requirements for drill pipe cleaning efficiency, this paper designed an auto-cleaning drill pipe device based on high pressure water jet technology. The device has some advantages of high automation and good cleaning effect. At the same time, it can also be adapted to cleaning flow line operations and meet the requirement of drill pipe cleaning in the practical application.Based on the extensive survey of research status and development about high pressure water jet clean technology and devices, firstly this paper summarized the trend of drill pipe cleaning devices and the key issues while designing. This paper carried on the mechanism of cleaning drill pipe dirt by analyzing drill pipe structure and the characteristics of fouling materials. An auto-cleaning drill pipe technology solution is proposed, and then the overall layout, main technical parameters and automatic control processes of auto-cleaning device for cleaning23/8in to51/2in drill pipe are done. Besides, this paper determined the structure and design calculation of the device’s key components (automatic transmission-line system; polished drill pipe wall system; integrated high pressure water jet clean system) based on the overall scheme of the auto-cleaning drill pipe device. Its structure is reasonable by initial verification. These components’ detailed two-dimensional drawings are drew up by AutoCAD. A solid model and the general assembly drawing of these components are built by Pro/E. At last, this paper analyzed jet flow field characteristics of nozzle for drill pipe cleaning execution unit. According to the theory of computational fluid dynamics, different nozzle structural parameters (including the cross-sectional shape of nozzle hole, shrink corner, outlet diameter, aspect ratio, etc.) are optimized by using Fluent software. After selecting the best of nozzle structural parameters, nozzle cleaning parameters are analyzed to obtain the best cleaning target distance and the best cleaning impact angle. These analyses provided to guide in the nozzle design and installation for the auto-cleaning drill pipe device.In summary, based on a wide range of domestic and foreign research of high pressure water jet cleaning technology and devices, combined with the structural characteristics of drill pipe, the nature of fouling materials and the mechanism of cleaning drill pipe dirt, a new auto-cleaning drill pipe technical solution is proposed. An auto-cleaning drill pipe device is designed and developed on the basis of the technical solution, and a detailed structural design and analysis of its key components are also developed, which has important social significance and economic value to improve the use of integrated drill pipe cleaning control by high pressure water jet cleaning technology in the oil industry.