Patent ID: 6062313
Filing Date: 2000-05-16
Classification: E21B

Abstract:
A system for separating particulate material from drilling fluid for underwater wells of a type which comprise a drilling platform, a string of drill pipe extending from the platform to a subsea floor for drilling the well, an annulus extending into an earth formation beneath the subsea floor, the drill pipe running through the annulus into the formation for drilling a well in the formation, a means for circulating the drilling fluid downwardly through the string of drill pipe and upwardly through the annulus for removing particulate material generated from drilling the well, the system further including a return conduit and pump for returning the drilling fluid to a water surface, the system comprising:a. an expandable tank positioned on the subsea floor and connected between the annulus and the return conduit so that the drilling fluid flows through the tank;b. the tank being shaped and dimensioned to allow at least a substantial amount of particulate material to settle out of the drilling fluid a as the fluid flows through the tank to the return conduit.