Effective way to increase core yield and quality in frozen rocks
Abstract
The most important task of exploratory core drilling is to ensure high yield and quality of core - source material for geological and engineering-geological sampling. Analysis of production data of a number of organizations engaged in drilling in permafrost rocks shows that when drilling with flushing the core yield is 60-70% for bedrock with moisture content of 2 - 5% and 20-30% in rocks with moisture content of 15% and more. In production conditions very often in order to increase the core yield one switches to “dry” drilling. However, the core quality deteriorates sharply. Partial or complete thawing of the core takes place with violation of its structural characteristicsю
References
- Baskilovich I. A., Kudryashov B. B., Stepanov P. M. To the possibility of rotary drilling with bottom-hole cleaning by cooled compressed air at placer gold deposits. Proc. CNIGRI, Coll. 69, М., 1967.
- Elmanov I.P. Drilling of Exploration Wells with Air Blowing in Permafrost Rocks. Nedra, 1965.
- Kudryashov B. B. Normalization of the temperature regime of boreholes when drilling through permafrost rocks with bottom-hole air purging. The present collection.
- Kudryashov B. B., Kirsanov A. I., Stepanov P. M. Thermal regime of the well while drilling with bottom-hole air cleaning on permafrost rocks. In the collection: Theory and Practice of Drilling a Well with Air Bottomhole Cleaning. VNIIOENG, M., 1967.