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Posted by Geoman on August 10, 2007, 8:43 am
>
>>I have very interesting proposal for you
>>pull you pipe lines out of well if any
>>now shove stick of delamite in to well
>>"fire in hole"
>>that will open the hole and you may get
>>even the oil out of it. "You never can tell"
>>on the other hand I would take Bobs advice
>>Tony
>>
> Good GAWD-a-mighty, Tony.
> What in the hell language are you speaking?
> Are you "free-basing" or "speed-balling" or whatever the hell?
> Bubba
Tutle?
>
>>>I have a new house with an open-loop geothermal system. The house is two-
>>> storey with two heat pumps; a 5 ton unit for the first floor, basement
>>> and crawlspace and a 3 ton unit for the second floor. Used since last
>>> fall. Got great heat in winter with no red lights for the auxiliary
>>> heat,
>>> even on coldest windy nights (-35 degrees Celsius). Cools even better in
>>> recent heat wave (35 degrees Celcius). I am in Winnipeg, Canada where it
>>> gets pretty cold but only gets very hot for a few weeks.
>>>
>>> I have two problems, perhaps partly related.
>>>
>>> Most serious is that the injection well was overflowing by the end of
>>> winter. Normal static level is about 25 feet down casing with about 8
>>> foot rise when both units are running. When it overflowed I could see
>>> that there were a lot of bubbles, more than a pot at full boil.
>>>
>>> My pump rate is 21 USgpm.
>>>
>>> The bubbles were caused by pressure reducing valves (PRV's) that were
>>> installed downstream of each unit. When I cranked the PRV's wide open
>>> the
>>> bubbles stopped and then came back when I reset the PRV's. I did this
>>> several times and definitely isolated the bubbles to the PRV's.
>>>
>>> I was told that the PRV's were necessary because the installers adjusted
>>> the flow rate through each unit to limit the leaving water temp to 38
>>> degrees F so that there would be no risk of freezing the exchangers.
>>> This
>>> seems exactly incorrect to me since slowing down the flow would allow
>>> the
>>> unit to draw more heat from each gallon of water and thus reduce the
>>> leaving water temp. To prevent freezing you should speed up the flow so
>>> each gallon gives up less heat and the leaving water temp would be
>>> higher.
>>>
>>> The bubbles air locked the well, at least part of the problem was solved
>>> by installing a pump down the injection well and pumping out for a
>>> while.
>>> Then going back to the main house pump in injection mode. A lot or air
>>> was discharged, quite violently, from the well. A few cycles of this and
>>> I solved most of the problem - the mound up is 2 or 3 feet higher than
>>> last summer.
>>>
>>> I don't know if the remainder of the capacity loss is more air in the
>>> formation that I can't get out or possibly calcium or iron precititation
>>> partially plugging the limestone formation. I acid treated these wells
>>> after they were installed and that really increased the capacity so I
>>> can
>>> always do that again.
>>>
>>> The wells are both open holes in limestone formations, no screens at
>>> all.
>>> Sometimes I get a small amount of sand plugging the filter in the
>>> basement but not much - about a tablespoon of sand once every 3 to 6
>>> months. When I get the sand I just run the main pump on high to a pipe
>>> to
>>> the river for a few hours and the sand goes away for a few months. I may
>>> have to borrow a larger pump so I can over-pump the well to get rid of
>>> more of the sand. It's not the main problem anyway.
>>>
>>> My biggest problem is iron bacteria infection. I have been getting red
>>> slime on the filter to the extent that I have to clean it every 2 to 4
>>> weeks. I have also learned that the bubbles could have caused both iron
>>> and calcium to precipitate out of solution. The water tested high for
>>> calcium hardness and maxed the iron bacteria colony counts.
>>>
>>> I have researched well disinfection both from local experts and internet
>>> googling. I learned that the infection usually comes back. I figure that
>>> is because the methods used for domestic water wells are not adequate,
>>> or
>>> more accurately not enough, for geothermal open-loops. Since we have
>>> been
>>> pumping for a year now the bacteria has been spread through the
>>> limestone
>>> formation between the wells. Testing shows a 4-inch drop at one well
>>> when
>>> pumping the other well and discharging to ground. This is a good dis-
>>> connection from the point of view of geothermal heating or cooling but
>>> any connection at all will lead to spreading the infection. So I figure
>>> that the reason the infections always return may be that you have to
>>> disinfect the whole flow path between the wells to get all of the
>>> bacteria. If you just disinfect each well then as soon as you go back to
>>> normal operation you will suck the bacteria that were out of range of
>>> the
>>> chlorine into the system and you are back at square one.
>>>
>>> I am thinking of siphoning chlorine into the discharge pipe in the
>>> injection well for two weeks or so. This should get chlorine into the
>>> flow path between the wells and hopefully solve the problem once and for
>>> all. My concern is that I calculate the chlorine ampount as over $1500
>>> for just 50 to 100 ppm, more for the higher concentrations.
>>>
>>> Has anyone done any well disinfection? If so, was it successful and, if
>>> so, what did you do?
>>
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