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Advances in Materials Science and Engineering
Volume 2015, Article ID 340721, 6 pages
Research Article

Predicting Equivalent Static Density of Fuzzy Ball Drilling Fluid by BP Artificial Neutral Network

1College of Petroleum Engineering, China University of Petroleum, Beijing 102249, China
2SJVBU, Chevron North America, Bakersfield, CA 93311, USA
3CNPC Key Laboratory for Petroleum Drilling Engineering Lost Circulation Control Division, Wuhan 430100, China

Received 8 January 2015; Revised 23 May 2015; Accepted 14 June 2015

Academic Editor: Michele Iafisco

Copyright © 2015 Chen Yang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A back-propagation artificial neutral network model is built based on 220 groups of PVT experimental data to predict the equivalent static density versus depth for fuzzy ball drilling fluid which is a kind of gas-liquid two-phase material. The model is applied in the Mo80-C well located in Sichuan Province of China; the maximum relative error between calculated results and measured data is less than 2%. By comparing with the multiple regression model, the present model has a higher precision and flexibility. The equivalent static density of fuzzy ball drilling fluid from ground to the depth of 6000 m is predicted by the present model, and the results show that the equivalent static density of fuzzy ball drilling fluid will decrease slowly with the growth of depth, which indicates that the gas cores of the fuzzy balls still can exist as deep as 6000 m.