DEVICE FOR CLEANING OF DRILLING FLUID Russian patent published in 1999 - IPC

FIELD: bore-hole drilling technology. SUBSTANCE: device is used in drilling oil, gas, and geological prospecting bore-holes. Device has body with pipe unions for inlet of used drilling fluid and for outlet of cleaned drilling fluid. Installed inside body is unit of filter elements in the form of concentrically arranged screens with cells of different sizes. Connected to lower part of body is sludge conveyor in the form of auger installed at angle with respect to vertical axis of body and it is enclosed in housing. Made at top end of housing is opening for discharge of sludge. Actuator of unit of filter elements takes the form of vibrator with rotary and oscillation motion. Device is provided with pipe union for draining liquid phase of drilling fluid. One end of pipe union is located on conveyor housing at level which is higher than level of location of pipe unit for introduction of used drilling fluid. Other end of pipe union is connected to upper part of body. Drain pipe union is provided with gate valve. Nozzle is installed in introduction pipe union. Drain pipe union is located below sludge discharge opening. Angle between axes of auger and body is equal to 10-50 deg. Device is provided with jet pump. Connected to suction chamber of jet pump is pipe union for outflow of cleaned drilling fluid, and connected to nozzle inlet is centrifugal pump for delivery of clean drilling fluid. Device can be provided with open vessel with additional outlet pipe union in upper end of its side wall. Located in this vessel is device together with lower part of conveyor up to level of location of gate valve in drain pipe union. Outlet of jet pump is connected to vessel interior. Pipe union for introduction of used drilling fluid is connected to vessel interior by means of non-return valve. Aforesaid embodiment of device ensures high degree of cleaning drilling fluid together with high productive capacity. Second stage of cleaning drilling fluid in hydrocyclones is thus made unnecessary. Aforesaid advantages are made possible due to following: tapered form of filter body and filter elements, rotary-oscillation motion of filter elements, tangential inlet of uncleaned drilling fluid, additional withdrawal of cleaned fluid by jet pump, flow of uncleaned fluid with filtered out rock matter down of body by means of permanently operating auger having drain pipe union for return of liquid phase of drilling fluid back to body. EFFECT: higher efficiency. 10 cl, 3 dwg