How to deal with drilling fluid leakage during the operation of shale shaker?
This phenomenon is mainly caused by three kinds of reasons.
1.High content of solids phase particles, high fluid viscosity, dispersion of cuttings and other incidents relating screened materials;
2.Small vibration force, high screen mesh, small screen area and other self-related conditions of shale shakers;
3.Direction and position of liquid inlet when installing shale shakers in the field.
These points are analysed below.
First, the screen mesh selected is unreasonable. The handling capacity of each shale shaker is 50L/s. Since drilling in the surface layer is faster, more solids phase particles are produced and occupies effective screen area, the fine-mesh screens can't be used in shallow well. In the beginning of drilling, large mesh screens should be used and with the increase of drilling depth, adopt more fine mesh screens gradually.
Second, the situation of layer and drilling fluid influence the handling capacity. As the chemicals added in the drilling fluid are not fully dissolved and paste on the screen, a serious fluid leakage will occur.Another situation is, when drilling into soft sandstone layer or sand layer, the sand grains are easy to stuck in the screen holes and leads to screen blocking.
Third, check if the rotation direction of the motor is correct. First, remove the vibrator shield, check if the rotation direction of eccentric blocks of the two motors are all revolving outward. Second, if the rotation direction is incorrect, please exchange any two phase lines of the input power supply in the electric cabinet.
Fault performance one, although the shale shaker can remove cuttings to the sides, when the two motors revolve inward, the separating speed is very slow; Fault performance two, if the two motors have the same rotation, the vibration force is very small and no sand and drilling fluid will be handled at this time.
Fourth, inspect the amplitude of shale shaker. The larger the amplitude is the larger the handling capacity. Adjust the vibration force to 90 before manufacture completed. If fluid leakage occurred, align the angles of inner and outer eccentric blocks, then the vibration force will be 100 (the handling capacity only increases by around 15) .
Fifth, check if the liquid flow distribution in the sieve frame is reasonable. Both sides of the screen surface of the hook-edged structure screen shale shaker are lower than that in the middle, the drilling fluid is easy to leak to the sides, so you should make sure the drilling fluid flows in the middle of the sieve frame. To accomplish this, we can apply two methods. The first is adjust the front spring seat and lift the front angle of screen box; The second is adjust the position of the turnover plate of extending grooves to control liquid flow distribution.