WorldWide Drilling Resource

Notes from the Groundwater Guy by Thomas E. Ballard, P.G., C.H.G. Southeast Hydrogeology, PLLC Common Causes of Well Failure - Inadequate Well Development I’ve talked about well development before, and it remains true - inadequate well development is still one of the biggest problems with wells we see, both in terms of outright well failure and well underperfor- mance. A well that is not developed properly can continue to underperform throughout its entire life, re- sulting in premature failure. The purpose of well development is to remove drilling mud and “skin” damage on the borehole wall; to settle the filter pack and remove sand “bridges” and other formation fines; remove fines/sand from within the well; and reduce turbidity. All these actions, of course, result in the most efficient flow of groundwater to the well. So, what can go wrong with well development? A lot, actually! Not enough time devoted to well development: Our experience with well bids is, the development component is almost always underbid, usually resulting in a change order if the well development is done correctly. If significant quantities of drilling mud are lost into the formation during drilling, the development process is going to take correspondingly longer. Not using measurement parameters during development: Measurement of specific capacity, sand and turbidity, at a minimum, and continuing development until no substantial improvement is noted in any of these parameters will assure complete development. Delays in starting the well development process: Especially in wells drilled with mud, delays in starting the well devel- opment process can result in the mud gelling to the point where it becomes difficult or impossible to remove, resulting in a well that permanently underperforms. Not using the proper development techniques: Most drilling muds are going to contain a certain amount of polymer to enhance their effectiveness during drilling. This can present problems during the development process as dispersants, that work well on the actual bentonite-based mud, are less effective in removing the polymers, which can often require something like chlorine to break them down effectively. Contaminants in drilling mud: Evidence is mounting that drilling mud can contain arsenic, lead, mercury, chromium, magnesium, etc., making it critical that all the mud is removed during the development process to avoid “phan- tom” water quality issues. It is often hard to estimate the total well development effort in the bidding process. One of the things I always tell my clients is, if they are going to get a jus- tifiable change order, it is likely going to be for well development. The bottom line with well development is, you are not done until you are done. Tom Tom Ballard may be contacted via e-mail to michele@worldwidedrillingresource.com 32 NOVEMBER 2019 Congratulations to : Lauren Crenet i ISEE Cleveland, OH Winner for October! Time for a Little Fun! October 2019 Puzzle Solution: Star Iron Works, Inc. America West Drilling Supply Win a prize! Send your completed puzzle to: WWDR PO Box 660 Bonifay, FL 32425 or fax to: 850-547-0329 Can you identify which classified ads in this issue these two photos came from? Foundations by: Pile Dynamics, Inc. Piling Driving Hammer Performance December 10 ~ ONLINE WEBINAR phone: 216-831-6131 www.pile.com Horizontal Directional Drilling by: Technical Toolboxes Horizontal Directional Drilling (HDD) Technologies for Utility and Pipeline Application December 10-11 ~ Houston, TX phone: 713-630-0505 www.technicaltoolboxes.com Pumps by: Franklin Electric Irrigation / Industrial December 10-11 ~ Wilburton, OK phone: 800-348-2420 www.franklinwater.com/more/ training/franklintech-schedule/ More education opportunities during events can be found online at worldwidedrillingresource.com Education Connection WTR You are not done until you are done. WorldWide Drilling Resource ®