What are your average drilling speeds?

We do the same exact method as Eric but we use fresh water for mixing grout, and move the pan off the hole before setting the loop and grout pipe. That way we can set the rig up on next hole for drilling while grouting is done on the looped hole.

 

Ok. So now I can

See the bigger picture. You guys are in the lucky location of less regulation than we have here. We don't get the luxury of being able to use our drilling fluid as grout and vice versa. No grout mixture may contents may contain the words slurry, gel or polymer. So we are required to make separate batches. One for drilling and the second is the thermally enhanced grout. Hence my confusion on the recycling of you mud.

Thank you guys again for the helpful insight. Once we get going on this project I will snap some pics for you guys to critique.

Mark
H2o well service

 

Mark,

We are drilling and installing loops in Utah. If we can help, let us know.

 

Hi Mark,

The words thermally enhanced were critical to discussion. However it does not slow the process down, it actually speeds it up.

For thermally enhanced grouts a tottaly seperate grouting operation is indicated. Drill rigs drill holes, grouters grout. Drill a hole, set the loop, pull up. Grout machine and crew follow the drill crew, and provide additional support for tripping out of the hole as needed.

At the end of the day, don't believe everything you hear about grout, enhanced or otherwise. It is all just bentonite mixed with water, some has sand added, some does not.
Eric

 

We use Baroid 30 mesh grout mixed to 20% solids on our standard bids.
When enhanced grout is specified it usually called for at a 0.88 mixture (50 lbs barotherm with 200 lbs 000 sand).

Our standards call for potable water to used for mixing grout too. I've used our drilling mud when we low on water in the past, but prefer clean water.

 

Does that baroid 30 mesh in the plain brown paper bag have a NSF number or designation? The 30 mesh I can buy does not. I was recently advised that you should not put anything in the ground without the minimum NSF number, or you would/could be at risk from big brother.

Knowing what I know about NJ, I would check that out if I were you.

Eric

 

No the brown bag does not have the NSF number on it.
I will look into further, but I believe I remember something about being 100% pure bentonite with no additives that's safe to use.
What are you using for grouting?

 

I am in the proccess of field testing and developing a proprietary grout of my own. Thats how I found out about the nsf number.
Eric

 

Just a little update. I asked around and this is what I've been told.
Since it is 100% pure crushed bentonite with NO additives then there is no need for the NSF.
The other products have additives and they have to be approved by NSF before using them.

Proprietary grout. YIKES! I wouldn't want the hassle. God bless ya! Good luck,

 

I am surprised at that response out of NJ. I was told anything manmade that you put in the ground needed a nsf number, if only just to say they reviewed it and you are good. A CYA more than a need.

Do you use any additives with the 30mesh? Polymers or ect.? Or do you mix it straight and shoot it fast?

Everything in my life is profit/cost driven. On the residential side of our business we are currently consumeing 2700 bags of grout per year, give or take. Any reduction in the costt of that product will make a huge differance in our operateing costs.

I used 30 mesh briefly and paid $8,25 a bag. The grout I am trying to develop may end up being 1/2 that. Thats why I am wanting the "hassle".

What does the 30 mesh cost on your side of the bay?

Eric

 

I mix a 150 lbs at a time with 72 gal water. Add the bags to the water, blend for 2-3 mins until it starts to hydrate then start pumping.
We are paying about 10/bag delivered.

 

Dth Drilling

1 h setup 1-5 h Casing (10m/h) and then the hard rock 40m/h 1 h setting the loop cleen up and be on the road.

 

Nemek,
So your at 5-6 hours for a looped,grouted 300 borehole?
I am assuming this is fairly average times?

 

Yes its avarage, and we dont grout

 

groute,, Its normally not used in Sweden for energy drilling and loops, We use to go down to the bed rock whith steel casing, cement it tight to the bed rock, no leaking water from the dirt,,clay,what ever it is down in the hole. Drill down and use the water we get in the bed rock or filling it up. water as conduktor. and hole seald tight.

 

So im very new in the drilling industry and got a issue with getting all my drill cutting out of the hole. I imagine its is drill cuttings as I cant get my sleeve down.

Is there a possibility that I am drilling to fast and using to much down pressure keeping in mind my small rig have hydraulic downwards pressure as well or should I get a stronger mud pump. This coming back to how long does it normally take to drill a lets say 30 meter hole?

 

There are 2 1/2 drillers active in this site that can help you. I am the 1/2 since I'm not on nearly as much anymore.
We're going to need a little more info to try to help you though.
What kind of drilling equipment are you using?
What kinda of ground are you drilling into?
What kinda of mud pump do you use?
What size borehole is being drilled?
I'm sure the other two drillers will respond shortly too ( water pirate & palace geothermal).

 

Thank you for the reply.

Im using a small drill rig with 1 meter drill rods. The rig is hydraulic with a pulling and pushing hydraulic force.

Im having this problem in areas where i drill clay and this is 80% of the time.

Im using a 4,6 horsepower dirty water pump that most people are using drilling with small rigs.

Currently im drilling with a 160mm drag bit to fit a 110mm pvc sleeve.

The problem is i reach my depth no problem and it SEEMS my water flow stays the same but as soon as try to lower my sleeve it gets stuck plus minus 3 meters down the hole. In some areas we encounter a white clay that is also sticking to my drag bit. Im using a polymer but seems not to be neccesary as this clay is also a good drilling (mud)

Can it be that im drilling to fast and my drill cuttings is to heavy to be flushed out of the hole or can it be that my pump is not pumping strong enough to push the cuttings out the hole?

 

Sounds like your using a tractor mounted rig or some sort of attachment style drill rig?
That style of rig is going to be extremely unreliable at best. Your pump is also extremely small and not going to maintain the volume of mud movement needed to lift clay cuttings for the borehole consistently.
If your using a dirty water pump as a mud pump the viscosity of drilling fluid combined with the weight of drill cuttings is going to easily overpower the pumps abilities.
I have heard of those rigs working, but typically after many failed attempts first.

 

I never never use spud mud to drill a production hole. Spud mud being you get what the ground gives you. That being said, Dan is correct that you are limited by your mud pumps capacity. You overcome that capacity issue by drilling slower as you already identified as a probable cause. time is also your friend. After you reach total depth, do not be in a hurry to trip out of the hole, it is not clean. Give it some time and let your fluid thin and bring cuttings to the surface.
There has also been tons of research done on selecting the correct fluid for drilling in sticky clays and shale to prevent bit balling and swelling, which is the other problem I think you have. When drilling reactive clays I am a big fan of barroids ez mud gold. It is a straight polymer in dry form that mixes easily and gives viscosity as well as a coating to help prevent swelling and prevent the cuttings from balling up. Are you running a reamer of any description above your bit?
Eric