Effect on the Performance of Drilling Fluids at Downhole Rock Surfaces at Low Temperatures

作     者：Mingming Zheng Guosheng Jiang Tianle Liu Fulong Ning Ling Zhang V.F.Chikhotkin Mingming Zheng Guosheng Jiang Tianle Liu. Fulong Ning Ling Zhang V. F. Chikhotkin

作者机构：Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring (Central South University) Ministry of Education Engineering faculty China university of Geosciences Key Lab of Drilling and Exploitation Technology in Complex Conditions Jilin University 

出 版 物：《Journal of Earth Science》 (地球科学学刊（英文版）)

年 卷 期：2016年第27卷第5期

页      面：856-863页

核心收录：

学科分类：081801[工学-矿产普查与勘探] 081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：supported by the National Natural Science Foundation of China(Nos.41502346,51274177) the Fundamental Research Funds for the Central Universities(No.CUGL140819) the Open Research Fund Program of Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University) Ministry of Education(Nos.2016YSJS005,2016YSJS011) the Open Research Fund Program of Key Lab of Drilling and Exploitation Technology in Complex Conditions(Jilin University)(No.DET201610) 

主　　题：gas hydrate bearing sediments low temperature drilling fluid performances downholerock surface strength influence mechanism. 

摘      要：To maintain gas hydrate stability, low-temperature drilling fluids and high drilling speeds should be used while drilling in gas hydrate-bearing sediments. The effect of the drilling fluid on downhole rock surfaces at low temperatures is very important to increase the drilling rate. This paper analyzed the action mechanism of the drilling fluid on downhole rock surfaces and established a corresponding evaluation method. The softening effect of six simulated drilling fluids with 0.1 wt.% of four common surfactants and two common organic salts on the downhole rock surface strength was evaluated experimentally using the established method at low temperature. The experimental results showed that the surfactants and organic salts used in the drilling fluids aided in the reduction of the strength of the downhole rock surface, and the established evaluation method was able to quantitatively reveal the difference in the softening effect of the different drilling fluids through comparison with water. In particular, the most common surfactant that is used in drilling fluids, sodium dodecyl sulfate（SDS）, had a very good softening effect while drilling under low-temperature conditions, which can be widely applied during drilling in low-temperature formations, such as natural gas hydrate-bearing sediments, the deep seafloor and permafrost.