Difference between revisions of "除泥-亚洲除泥法"
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除泥是一种人工钻取技术，使用这种技术时，水循环将钻屑带到地表。钻杆上下移动。在下冲程中，钻头将土壤钻得疏松，而在上冲程中，钻杆的顶端由把手（或阀门）关闭，通过钻杆来抽取水并将钻屑转移到地表。在下一个下冲程中，通过把手（或阀门）将钻杆的顶端打开，水喷射至水井前面的坑中。在坑中，钻屑与水分离并沉淀，同时水从坑中流出，从而流回水井。
由于水压作用，井眼不会闭合。通常往水中添加一些增稠剂（例如黏土、膨润土、甚至是牛粪），以防止洞坍陷并减少作业用水的流失（钻井液）。
适宜条件
适合疏松地层: 沙子、淤泥和黏土。如果旋转（包括使用钻头），有可能穿透更软的压实地层，例如硬黏土、软砂岩和风化红土。
很难钻入更坚硬的地层。为了解决这个问题而发明了Rota 除泥法。
无法钻入粗砾石和其他极易透水的材料（地层中的裂缝）会导致作业用水流失。如果在钻至井眼三米之前钻到细砂（流砂），则需要再加一层临时套管和膨胀黏土以防止塌陷。
使用除泥法（无论有无旋转）可钻达35米深。
| Advantages | Disadvantages |
|---|---|
| - Easy to handle and a temporary casing is normally not needed. It is possible to construct the drilling equipment locally. - Faster as augering or percussion, as the drilling pipe can be easily extended during the drilling process, and does not need to be removed from the borehole during the process. |
- The borehole stays open by water pressure. To prevent collapsing, fluid-drilled boreholes must be kept full of water during the entire drilling and well installation process. |
Construction, operations and maintenance
Equipment is very cheap and can be produced locally.
Field experiences
Mainly used in India, Bangladesh, Nepal and Chad.
Manuals, videos and links
- Rota-sludge and Stone Hammer drilling, part one: Drilling Manual by Practica Foundation. Rota-sludge and Stone Hammer drilling, part two: Production Manual by Practica Foundation.
- Drilling & well construction reference manual, Lifewater Canada, update 2004. Internet manual on hydrogeology, well construction, all drilling techniques, hand pumps and more. Download manual. Other information can be found on the Website of Livewater.
- KOEGEL, R. (1985) Self Help Wells, FAO Irrigation and Drainage Paper, FAO, Rome.ISBN 92-5-100398-X html version.
- CARTER, R. C. (2005) Human-Powered Drilling Technologies. an overview of human-powered drilling technologies for shallow small diameter well construction, for domestic and agricultural water supply , Silsoe College , Cranfield University , Bedfordshire, UK Download
- Drilling Boreholes for Hand pumps, Peter Wurzel, Skat, Switzerland, 2001 - A book on hydrogeology, well construction, drilling techniques, well development - Download. Website of SKAT
- Low-cost shallow tube well construction in West Africa, M. Sonau, FAO - An overview of shallow tube well drilling techniques - website. Website of FAO documents.
- Technical note 43. Simple drilling methods, Bob Elson and Rod Shaw, WEDC - An overview of simple drilling methods Download. Website of Loughborough University Technical Briefs section. Website of Loughborough University WELLS.
- A Water Handbook, Technical Guidelines Series, UNICEF, 1999 - Programming and implementation. Download.
- Technology notes, section 7; Tube wells and boreholes, WaterAid - An overview of human-powered drilling technologies. Download. Website of Wateraid.org.
- Multi-service procedures for well-drilling operations, field manual chapter 9, US Military Chapter 9, alternative well construction, manual drilling techniques - Download.
Acknowledgements
- The basis for the material on this page was obtained from a desk study shortly to be published on the website of the Practica Foundation, and from the Rural Water Supply Network, and specifically its manual drilling section.
- 43. Simple drilling methods. WEDC.
