Drilling fluid cooling technology is one of the key techniques of drilling technology. In order to study the influence of mechanism of drilling fluid on temperature and pressure, especially on thermophysical parameters and rheological properties, as well as the heat transfer mechanism between bubbles and liquid flow inside and outside the liquid film by test, simulation and theoretical research. Firstly, the test on thermophysical parameters of 10 kinds of drilling fluids at 7 different temperatures and 3 different pressure were analyzed, which would provide the key parameters for the establishment of downhole gas-liquid two-phase model. Then, study on rheology of cement slurry under high temperature and high pressure, and its heat transfer equations were derived. The results showed that the specific heat of mud decreases with the increase of density, and the thermal conductivity increases with the increase of density, almost linearly. Besides, gas is the main factor affecting heat transfer inside the well.
To improve the drilling efficiency of impregnated diamond drill bit in strong abrasive rock layer, this paper introduces the theory of primary and secondary abrasives into the drill bit design, and explores the drilling efficiency and service life of diamond drill bits with six formulas of primary and secondary abrasives through indoor and field tests. The results show that the drill bits with primary and secondary abrasives had an 85% higher efficiency and a 46% longer service life than the conventional drill bit. In the course of drilling, the matrix of the ordinary drill bit was soon worn out due to the repeated grinding by a large amount of medium and coarse rock powder, losing the ability to hold the diamond in place. Then, the drill bit became less durable or efficient. These defects could be overcome by our diamond drill bit design. If applied to strong abrasive formations, the primary and secondary abrasives of our design can crush the medium and coarse rock powder into finer powder. The fine rock power can be discharged timely and rapidly through the bit end via the drilling fluid.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.