POLYCATIONIC DRILLING FLUIDS WITH SHALE CONTROL PROPERTIES
Gaidarov, Azamat M. – student, Russian State Geological Prospecting University of S.Ordzhonikidze, technician, LLC Gazprom VNIIGAZ, A_Gaydarov@vniigaz.gazprom.ru
Khubbatov, Andrey A. – deputy head of laboratory LLC Gazprom VNIIGAZ, Cand.Tech.Sci., A_Khubbatov@vniigaz.gazprom.ru
Norov, Azat, D. – scientific employee LLC Gazprom VNIIGAZ, A_Norov@vniigaz.gazprom.ru
Khrabrov, Dmitry V. – engineer grade 2 LLC Gazprom VNIIGAZKhrabrov, Dmitry V. – engineer grade 2 LLC Gazprom VNIIGAZ, D_Khrabrov@vniigaz.gazprom.ru
Sutyrin, Alexander V. – head of laboratory LLC Gazprom VNIIGAZ, Cand.Tech.Sci., A_Sutyrin@vniigaz.gazprom.ru
Gaidarov, Mitalim M.-R., head of division LLC Gazprom VNIIGAZ, Dr.Tech.Sci., M_Gaydarov@vniigaz.gazprom.ru
Key words: drilling muds, inhibiting properties, clamping properties, shales, life-time, coefficient of lifetime, drilling, polycationic system.
The paper provides information regarding deficiencies of conventional non-dispersing drilling fluids. Evidence is provided to describe the behaviour of shales and argillites on borehole walls when affected by various drilling fluids. The authors propose a new polycationic drilling mud system with excellent shale control properties to drill through expansive shales and potentially unstable clay-argillite deposits. It is shown that reduction in the inhibiting ability of drilling fluid leads to operating time increase and vice versa. In order to assess inhibiting properties of drilling muds, a new indicator – operating time factor — has been introduced. The most effective inhibiting drilling fluids for shale control in suprasalt deposits of the Astrakhanskoye gas and condensate field have operating time factor of 0-0,4.