Causes of Well Plugging Problems
Most of the time, plugging problems in wells can be separated into three different categories: physical or mechanical type blockages, mineral encrustation, and biological type plugging. Often the bacteria are the "glue" or the "cement" that will filter the minerals from the water and will also act as the "glue" or "cement" that will hold the fines from the surrounding formations as they are moving towards the pumping well. Thus, physical blockage and mechanical blockage can result as the fine material moves toward the pumping well and this can become packed up against the gravel pack, the void spaces of the formation, and to the well screen. The sulfate-reducing bacteria (SRBs) will cause microbial corrosion by growing within a tubercle and under the other slime-forming bacteria in a biofilm or nodule. These SRBs will also generate the "rotten egg" or the hydrogen sulfide odors. Much of the time iron forms red to brown types of deposits.