caa a22 4500 606226257 CHVBK 20210128101152.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s10553-015-0613-x doi (NATIONALLICENCE)springer-10.1007/s10553-015-0613-x Comparative Analysis of the Pressure Loss from the Circulation of Drilling Fluid During Microhole Drilling with the Use of Coiled Tubing [Elektronische Daten] [Hou Xuejun, Qi Zhilin, Liang Qimin, Sun Tengfei] The choice of fluid-circulation conditions is of great importance in microhole drilling (MHD) conducted with coiled tubing (CT) as the drill string because of the long length and small bending radius of the tubing coiled on the reel, which result in high circulation friction pressure loss (CFPL). A model for calculating CFPL in flexible CT has been constructed by combining a power-law fluid flow equation and the Dean Number. The calculations have revealed patterns of change in the CFPL during MHD. The CFPL in CT, whether reeled or in downhole, increases steeply with an increase of drilling fluid flow rate, decreases slowly with increasing CT inner diameter, and rises linearly with an increase in CT length. The total CFPL over the entire CT decreases slowly with decreasing CT length when the CT is run downhole from the reel. Deep MHD is suitable only for low drilling-fluid flow rates when the inner diameter of CT is large. Suitable ranges of drilling-fluid flow rate and CT inner diameter have been determined for various drilling depths. The research will provide a basis for selecting CT and drilling-fluid circulation parameters for MHD. Springer Science+Business Media New York, 2015 microhole drilling nationallicence coiled tubing nationallicence reel nationallicence circulation friction pressure loss nationallicence power-law fluid motion nationallicence downhole nationallicence Xuejun Hou Chongqing University of Science and Technology, Chongqing, China aut Zhilin Qi Chongqing University of Science and Technology, Chongqing, China aut Qimin Liang Research Institute of Petroleum Exploration and Development, Beijing, China aut Tengfei Sun CNOOC Research Institute, Beijing, China aut Chemistry and Technology of Fuels and Oils Springer US; http://www.springer-ny.com 51/4(2015-09-01), 361-370 0009-3092 51:4<361 2015 51 10553 https://doi.org/10.1007/s10553-015-0613-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10553-015-0613-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Xuejun Hou Chongqing University of Science and Technology, Chongqing, China aut NATIONALLICENCE 700 1- Zhilin Qi Chongqing University of Science and Technology, Chongqing, China aut NATIONALLICENCE 700 1- Qimin Liang Research Institute of Petroleum Exploration and Development, Beijing, China aut NATIONALLICENCE 700 1- Tengfei Sun CNOOC Research Institute, Beijing, China aut NATIONALLICENCE 773 0- Chemistry and Technology of Fuels and Oils Springer US; http://www.springer-ny.com 51/4(2015-09-01), 361-370 0009-3092 51:4<361 2015 51 10553