Measuring Samples

Measuring Samples

Obtaining accurate samples of the formation material is crucial for designing a sand-free well. The driller must use proper sampling techniques to collect representative samples of the native formation. These samples then need to be carefully sieved to determine the size distribution of the material particles.

Most screen manufacturers provide mechanical analysis services to evaluate these samples. Based on this analysis, they can recommend:

The proper screen slot size

When needed, the appropriate gravel pack material

This ensures optimal well performance while preventing sand intrusion.

Experience has shown several important principles regarding slot size selection:

Always use the largest screen slot size that is still compatible with the formation

Never compromise on proper slot sizing

Smaller slots clog faster (a 0.025" opening plugs twice as fast as a 0.050" opening)

Screens with coarser openings are easier to redevelop successfully

These guidelines help balance the need for sand control with maintaining good water flow and minimizing maintenance requirements. The sampling and analysis process provides the scientific basis for making these critical design decisions.