What are the recommended spatial relationships between formation, gravel pack and slot size?
A7. Selection of the proper gravel pack and screen slot size is one of the most crucial steps in designing water wells with high efficiency. Although several gravel pack gradation selection criteria exist, two of the most common techniques will be discussed here. Basic Gravel Pack / Slot Size Selection One of the more basic procedures involves performing a sieve analysis on representative water-bearing formation samples and selecting the finest aquifer gradation for determining the pack gradation. Using a typical sieve analysis form, the 50% passing (d50) size is then multiplied by a factor of 4 to 6 to establish the d50 of the gravel pack. Through the points defining the 4x d50 and the 6x d50 two curves are drawn which parallel the formation gradation curve. The percentages passing of the recommended gravel pack are determined where the curves intersect the lines corresponding to the standard sieve sizes. The gravel pack that is selected should ideally fall within the two curves and b
Related Questions
- If the lowest-priced generic is available in the recommended pack size but also in a larger pack size that has a lower unit price, which price should I record?
- What are the recommended spatial relationships between formation, gravel pack and slot size?
- Why is there a recommended pack size when data is collected on unit price?
