Page 114 - Shale Shakers Drilling Fluid Systems

CHAPTE R THRE E

Shale Shaker Design

The purpose of a shale shaker is to induce drill- If a single rotating vibrator is located away from
ing fluid to flow through a screen, transport sol- the center of gravity of the basket, the motion is
ids across a screen surface, and discharge solids elliptical at the ends of the deck and circular be-
off the end of the screen. Screening is the result low the vibrator (Figure 3-1). This is an unbal-
of using the energy developed by a rotating eccen- anced elliptical motion. If a single rotating vibra-
tric mass and applying that force to a porous sur- tor is located at the center of gravity of the basket,
face. The energy causes the screen to vibrate in the motion is circular (Figure 3-2). Two counter-
a fixed orbit or path. rotating vibrators attached to the basket are used
The elements of shale shaker design focuses on to produce linear motion (Figure 3-3). When placed
several aspects of the machine: at an angle to the basket, two counter-rotating
vibrators will produce a balanced elliptical motion
• Shape of motion (orbit or path) (Figure 3-4).
• Deck design
• "G"-factor
• Power systems

All of these parameters contribute to the results
achieved by a machine and each will be discussed
in this chapter.

SHAPES OF MOTION

Historically, the progression of shale shaker
design has been to allow the use of finer mesh
screens. They have developed through the years FIGURE 3-1. Unbalanced elliptical motion.
from relatively simple, uncomplicated designs to
today's more complex models. This evolutionary
process encompasses several distinct eras of shale
shaker technology and performance. These devel-
opmental timeframes can be divided into four
main categories:

1. Unbalanced elliptical motion
2. Circular motion
3. Linear motion
4. Balanced elliptical motion

The eras of oil field shaker (and screening) devel-
opment may be defined by the types of motion(s)
produced by the vibrators and their associated
machines. FIGURE 3-2. Circular motion.
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