Abstract:

The DL-1 device for lost circulation control simulates the extrusion and static pressure difference of the wellface by applying confined pressure, driving pressure and back pressure to the core, and simulates the state of the drilling fluid flowing in downhole annular space by using the model of parallel plate pore flow, which makes the shear stress of the drilling fluid to the core end plane the same as that to wellface, thus makes test conditions highly similar to downhole environment. This paper explains the thought, requirement and plan of the design of the device, and presents the main structural design. Test of the device conducted in Changqing oilfield for lost circulation control was successful.

Key words: Lost circulation control, Laboratory equipment, Design, Application