US 4,634,535 A · Drilling mud cleaning method and apparatus

Abstract

A mud slurry cleaning method including steps of distributing a mud slurry across an inclined primary separation screen, vibrating the primary screen through selected movement, cycle and frequency to screen out the liquid and selected particles, concurrently changing the geometric shape of the openings of the primary screen through each vibration cycle to free particles as might tend to lodge while concurrently impacting the primary screen at many spaced apart impact points to loosen particles tending to lodge, cyclonically separating the screened mud into a finally cleaned slurry and a thickened slurry including particles originally included in the original slurry, mixing the thickened slurry with a portion of the screened slurry to form a liquified slurry, distributing the liquified slurry across an inclined gleaning screen, and vibrating the gleaning screen as above described to screen out liquid and desired particles while concurrently changing the geometric shape of the openings of the screen and concurrently impacting the screen to loosen particles as above described. Mixing the clean slurry from the hydrocyclone separators with the liquid coming through the gleaned screen for return for use in the wellbore. Also discloses specialized apparatus used in the method.

Claims26

Dependent claims

A method of continuously cleaning a drilling mud slurry within an intergral and portable apparatus, comprising:

(a) receiving a drilling mud returns slurry containing particulate solid pieces;
(b) distributing said slurry across an inclined primary screen;
(c) vibrating said primary screen through a selected movement pattern, cycle and frequency to cause particles smaller than the primary screen openings to drop through the screen with the screened slurry and to cause other solids larger than said primary screen openings to move down the screen incline and off the primary screen;
(d) cyclicly changing the geometric shape of the primary screen mesh openings through each cycle of the movement pattern to free such particles as might tend to lodge in a primary screen opening of fixed geometry while concurrently impacting the primary screen at many spaced apart impact locations to loosen particles tending to lodge;
(e) receiving said screened slurry and remaining particles as pass through said primary screen into an accumulation of the screened slurry.

2 more elements

In an integral and portable vibrating screen apparatus adapted to remove liquid and selected particulated solids from a mixture including pieces of larger size, the combination comprising:

(a) housing means adapted to be vibrated through cycles of a selected frequency and through a movement of selected pattern between an upper position and a lower position;
(b) a supporting screen frame mounted within said housing to be vibrated by said housing and supporting an elongate screen means at a selected angle from the horizontal, said screen means comprising:
(1) upright support means mounted on said frame in a spaced apart array across the area of said screen with each of said support means defining a curved support knob at its upper end;
(2) an integrally formed elastomeric grid member mounted across the working area of said frame and vertically supported by said knobs.
(3) said grid member defining spaced apart first strands joined at substantially right angles to spaced apart second strands with a resilient, upwardly protruding stud formed at each intersection of said first strands and said second strands to form a spaced apart array of protruding studs;
(4) a woven metal screen of selected mesh per inch mounted across the working area of said grid member and vertically supported by said studs;
and
(5) screen retainer means clamping coincident edges of said grid member and said screen together as an operating screen unit and retaining said operating unit in a condition of selected tension across the working area of said screen for said grid member to be vertically supported by said knobs and for said screen to be vertically supported by said studs;
(c) vibrator means for vibrating said screen means through said housing means and said screen frame to cause cyclic vibration of said screen means through said cycles of said frequency and said movement;
(d) said vibrator means having means to modify the structure of said screen unit during a mud screening operation including:
(1) means draping said screen unit into a first curvature between said knobs beginning with the upward movement of each cycle of vibration as caused by the inertia of said screen unit and the mass of the mud slurry;
(2) means further draping said screen into a second curvature between said studs, beginning with said upward movement;
(3) said first curvature and said second curvature thereby changing the shape of each mesh opening of said screen during each cycle of said cycles;
(4) means flapping said screen unit beginning with the downward movement of each cycle of said vibration as caused by said inertia to thereby urge said mud slurry to part from said screen unit;
said screen to part from said studs of said grid member;
and said grid member to part from said knobs with said flapping resulting in the return of the initial shape of said openings;
and
(5) means slapping said screen unit against said knobs and said screen against said studs and said mud slurry against said screen through the end of said downward movement, tending to impart a jarring action, and to thereafter repeat said draping action as upward movement begins.

15 more elements

Dependencies are inferred from the claim text.

Drilling mud cleaning method and apparatus

Life of this patent

Drilling mud cleaning method and apparatus

Life of this patent

Abstract

Claims26