Published October 2015

The definition of rheological parameters of drilling mud when lifting drilling tool to prevent piston effect

I.Y. Shirali

Y.I. Safarov

It is known that when lifting the drilling tool in small gaps in annular space with high thixotropy of weighted drilling mud, the pressure sharply decreases, which leads to ingress of fluid from formation into the well and piston effect appearing. A method is proposed to define allowable values of limit static shear stress of drilling mud.