The shaker screen used was a commonly used model from Derrick called DX-A 100 where the mesh hole size is 175 micrometers. This shaker screen pyramid shaped grooves stretch From side to side. See Figure 1 and Figure 2.
When cooducting a test the most important question to answer is: what will we measure and why? This test aimed at investigating how a fast flowing stream of water or air should be ori ented relalive to a shaker screen and a horizontal ground plane.
Water and air are commonly available on oil rigs and the test was therefore limited to these two fluids.The fluids were pressurized and applied to the contaminated shaker screens in a stream .
To simulate a shaker screen in need of cleaning, clay for flower mud was mixed with sand and water. The clay mixture was applied to the shaker screens by hand. See figure Figure 3.
The test was initiated by rigging the equipment and investigating how to perform the test practically. The test was a factorial experiment where a number of factors are chosen and varied through a specific number of trials. To determine what factors that have a large impact on the cleaning result, a “screening” was done. This is a quick version of a factorial experiment where more factors are tested . No conclusion regarding how these factors affect each other can be made, but the factors that are important to the result can easiJy be distinguished.
The shale shaker screens were first polluted wirh the mud mixture and then cleaned with a combination of following factors:
- Air or water;
- The angle of the nozzle. Either parallel to the ground, nom1al to the shaker screen or with a 45° degree angle relative to the ground;
- Back or front of shaker screen;
- The orient ation of the pyramid shaped grooves, either vertical or horizontal
- The tilting of the shaker screen relative to vertical plane. Either parallel to the vertical plane or angled 45° relative to the vertical plane;
- The angle of the nozzle. Either normal to the shaker screen or 45° angled in the horizontal plane.
Then the time it took to get half of the screen clean was timed and documented.
The following conclusion was made.
The air pressure from the compressor dropped quickly as soon as a couple of seconds after in initiation. Apart from this, the air source had to be very close to the polluted area to have any cleaning affect. Also, the air almost “peeled” the dirt off the shaker screen surface and pushed it aside instead of removing it. With a greater constant pressure and several nozzles, air might have cleaned the shaker screens faster and with a better result. Even though, it was decided the air should not be the primary cleaning liquid. The cleaning fluid should be applied from the front. lf applied from the back, the areas of supporting frame gave a too large “shadow” under which the fluid caused little or no cleaning effect.