ECD optimization with specially designed low rheology drilling fluids.
Rafał Wiśniowski, Krzysztof Skrzypaszek, Piotr Kiebzak
Vol. 34, no. 1 (2017), s. 169-178, 
This article presents a method in which low rheology drilling muds are used as a solution for demand ing wellbore pressure management and high Equivalent Circulating Density (ECD) values. In order to investigate this problem series of numerical simulations were conducted. Real, field data from two already accomplished wells was used to recreate actual wellbores conditions in Halliburton Landmark Drilling Software and to calculate ECD values. In order to check and confirm the program’s results accuracy, the outcomes were compared with pressure while drilling (PWD) equipment surveys results made during drilling operations. Next, simulations were made in order to check how low rheology parameters of drilling muds will impact overall ECD values. Additionally in the article are included field tests results from Hibernia Platform, prepared by Bolivar, Joung et al. in 2007 where specially treated (TMSB) low rheology drilling fluids was used to mitigate lost circulation issues and extensive ECD values. Both researches’ results indicate that low rheology drilling muds may solve ECD optimization problems while still maintaining required properties and executing tasks of drilling fluids.