Input from the forum?

[yarg]

Just stumbled on this....I'm a mud rotary well driller from VA......nice project. Couple of general comments...with good mud, you can overcome a lot of things....carrying cuttings out of the hole is the first job of mud.....get yourself some bentonite and make a good mixer. Flow is key as well.....don't worry about pressure so much...shoot for an uphole velocity of at least 50 feet per minute...so a 6"hole needs 75 gpm flow. You can get by with less with the right mud though. As for pumps, you can drill a 250 - 300' , 8" diameter hole with a $1000 2" trash pump (honda's are the best). Don't ever push when drilling....you should always be holding back the weight of the drill string. You don't need a lot of speed...go for the higher torque motor. What kind of bit are you using? What kind of drill pipe are you using? Are you digging a mud pit or using a pan?

Hello VA Well Driller,

Thanks for your response. I am using a pan--about 150 gal. I will be using a High Torque motor and have float on my hoist so a minimum of down force can be maintained. I had a 2 inch fowmax pump that seamed to not provide enough PIS to keep the flow going but this could have been my roukie mud making actions?????? I switched to a 21 HP MCM Odrill mud pump that can make over 280 ft of head at 150 GPM. It is about a 3000 unit The other was about 1500 but it had really good oil bath seals but capped out at 24 PSI for 100 GPM, always seamed to not be able to flow---had to work the pipe after every length to get flow. I have read were some big rigs run hundreds of PSI and GPM for drilling 12 inch holes fown 1000+ ft.

I can keep this mud pump as the manufacturer has allowed me to purchase direct and less than the first pump but I need more HP to drive it. The pumps ability may allow for less issues with buyers?????

I have options of using schedule 80 black pipe or 2 3/8 x 3/16 wall DOM for my drill pipe. My rig may be fine with Schedule 80 black but it is only 30,000 yield VS 70,000 yield with the DOM. Yes, the DOM costs more but then, never should anyone overpower this pipe????????

Anything you can inform me of would be great! I am in an isolated area and have no one of experience to network with on this project.

I have purchased a Marsh vunnle and scale to make sure of my future mud---I feel that is the biggest issue I face.

Thanks and I hope to heard more input.

Gray

 

[VAWellDriller]

Sch80 black pipe is fine...the weak point is the connection, so you'll need to buy some tool joint connections and weld them on. My first rig we bought 2.5" sch 80 black pipe and Mayhew Jr tool joints, worked fine. Now I run 3.5" 0.368 wall rods from Star Iron Works with 2 3/8" IF connections. My rig has a 6000 ftlb tophead, and the most I've ever drilled was a 9 7/8" hole to 900'. We have a lot of loose sand up top, and we regularly drill a 17" hole to 100' to set 10 or 12 " surface casing. I have 3 mud pumps on my rig, a 2" air diaphragm mainly used for pumping cement grout, but you could drill with it. A mission magnum sandmaster 3 x 4 centrifugal with makes up to about 400 gpm and up to about 220psi, and a 5 x 6 Failing piston pump, capable of a constant flow of 180 gpm up to 350 psi. All have their advantages and disadvantages, but fundamentally when you are drilling, the only reason to have a pump to build a lot of pressure, is to overcome the friction loss through the drill pipe. If you are cleaning the hole and not overloading the mud with cuttings, you can literally pour mud in hundreds of feet of drill pipe and it will flow through by gravity. I hate drilling with a pan, and rarely do it if I can help it. You just don't have the volume to settle out and cuttings...you basically will suspend all the cuttings in the mud, then pump off and make up more mud. As for mud, around here, I drill above bedrock, in lots of clay with layers of shells, and gravel. We start with 50lb of bentonite per 300 gal of water, and then add a liquid polymer like WyoVIs from Wyoben or EZmud from Baroid. You should start with marsh funnel of 40 - 45 seconds and don't worry about weight until you start drilling, then start weighing it and try to keep it under 9.5 - 10lb / gallon. That will be hard in your pan, so you'll have to pump off and add water to thin it, but you should always add more bentonite or polymer with adding water to stabilize the hole. How deep are you planning to go? What kind of bit are you using? I use a Mills drag bit for clay, and a long tooth tri cone roller for hard shells and gravel or when I drill a big hole. The Mills bits cut fast, but they can hand a lot and snag, causing lots of torque on the drill rods and the rig. The tri cone sucks for cutting clay, but it will go through tough formations without a lot of torque buildup. I have to switch between the bits sometimes on the same hole.

 

[yarg]

This is all great information and I do appreciate your sharing it with me.

My pan is two 80 gal low profile tanks interconnected with a baffle near the pick up. You are right about recirculating the cuttings as I tried one pan and got heavy mud from cuttings.

Good to hear that schedule 80 will work as it is the least cost and easiest to get for me.
My pump will flow at 150 GPM at 120 PSI so I think this should allow up to 400 ft on a 6 inch hole?
I will get some of the polymer for my mud mixing-great info!
I am using a GP chevron bit with long reaming flutes and it does have lots of torque needs in rock and heavy gravels.

Anything more would be great and when I am done with the production rig, I will post Pictures?

Thanks again and more is better

Gray

 

[VAWellDriller]

You can do that hole easy with that pump, you could cut a 10" hole to 400' with that pump. What size casing? General rule of thumb is to drill a hole twice the size of the casing, or have at least a 2" annulus around the LARGEST OD of the pipe you want to set. Biggest thing people do wrong with mud drilling is go too fast. Drill slow, maybe 2-3' per minute on 6" with your pump, and wait long enough for the cuttings to come back before adding another rod. You may have to wait 20 minutes or even much more on deep to clean the hole, but it's well worth the wait. Build a bigger pan, get up to 300-400 gallons and it will make life much easier. If I loaded the picture right, you will see 2 farm tubs, discharge into the first, which contains most of the cuttings, pickup from the second. There is a connector hose between the two. With a 2 pan setup, you can keep most of the cuttings in the first and have clean mud in the 2nd. This holds about 400 gallons combined.

 

[jimmysisson]

Too bad you had to drill right next to the potty! Thanks for all the useful info, even if I'm not drilling.
Jim

 

[yarg]

More great info! Thanks! Yes, I can see the tubs and I am sure more settlement time make good sense. 400 ft is good news even if axtreemly seldom needed.
I will keep this pump I currently have because a change to a lesser pump will not save much and the old pump? It shut down flow at about 34PSI - just no room for any issues.
Nice, clean looking rig you have and looks like huge power on the drive. The rig only gets about 2 ft per hour in hard rock and 5.75 inches? I was drilling through ignious rock on the last job and it was work. Because I am drilling much smaller bore holes, I hope to be able to use less settlement pans? How do you seal the bore hole collar to keep the mud from leaking out? This has caused me trouble.


Just ordered schedule 80 for my drill pipe. Less nervous about until getting your note. Relaxed now, thanks.
Got the last of the supplies on a road trip today! Will be starting the first production build next tuesday.