Well Development

Well Screens and Open Hole Well Completions

All types of screened wells should be developed. The larger the openings (slots) in the screen, the more energy can be transmitted into the formation to aid in development of the well. Open hole well completions also should include development to remove fines and other unconsolidated materials in order to clear the water and increase production.

The Qwater Well Developer is designed to quickly develop wells by removing clays and silts and repair damage to the borehole wall caused by drilling. Proper well development also greatly reduces water turbidity while increasing well yield. A properly developed well saves sampling time and produces more representative formation water samples for laboratory analyses. Although designed to be durable, the Environmental Series Qwater Well Developers are priced to be disposable after each well use to prevent cross-well contamination, while the Production Series Qwater Well Developers are designed to provide many years of use.

Why Well Development is Important

The importance of well development for water supply wells has been known for more than a century. Well development removes the fine-grained materials from the borehole, which helps restore the formation to pre-drilling conditions to maximize production of water (yield) and reduce the turbidity of the water withdrawn from the well. The act of well drilling itself is a destructive process that damages the formation by compacting, smearing and forcing the clays into the borehole wall. Many development methods have been used to restore the formation to its natural condition after a well has been drilled. Attempts to remove the clays and drilling fluids have included bailing, air lifting (with compressed air), jetting with high-pressure water, over pumping and surging. Of all these methods, surging using the surge block is the most effective method for developing a well.
Drilling formation damage can occur by compaction, smearing, and fluid invasion during the following drilling methods:

Cable Tool/Direct Push
Smearing of clays into porous zones
Compaction of formation
High borehole fluid head forces water into porous zones
Augering
Smearing of clays into porous zones
Compaction of formation
Mud Rotary
Smearing of clays with drill bit
High borehole fluid head forces water into porous zones
Hydration of bentonite in porous zones
Removal of gel cake from drilling fluids

Using the surge block method helps restore the damage that occurs from drilling activities.

All types of wells need to be developed. These include:

Surging occurs as the surge block is pushed downward (downstroke), which forces water at a high velocity and pressure out of the screen. As the surge block is pulled upwards (upstroke), the muddy water is pulled into the screen and pumped out of the well. This back and forth working of fines through the screen suspends the fines in solution for removal from the borehole. Surging, followed by pumping the muddy water from the borehole, is the most effective combination for well development.