Shale Gas, The game changer.

[mikey_the_redneck]

Shouldn't we be looking for alternative energy that isn't a fossil fuel? We just don't learn.....

[Tiger]

Originally Posted by SeeGeeWhy

What do you mean by clean?

Clays are very sensitive to fresh water and shale is esstentially a mix of silty sand and clays. I'm not sure of the production mechanism in shale gas production i.e. does the gas flow to the wellbore via the sand lenses in the clays, with ultimate reserves being "fed" over time by the shale itself, or does the gas flow directly from the clay into the wellbore? This is somewhat important because VERY fresh water would cause any clay imbedded within the sand to "gum up" and prevent gas production all together. You need a certain level of salinity in order for the clays to remain stable and the sand to remain clean in conventional gas completions.

Shale gas is probably a different animal (again, I've never worked on these types of wells), with the sand proppant actually holding the clays open after they are "broken" by the pressure induced during the fracturing operation. In that case, I am not sure how you design your completion fluid.

Perhaps it is sensitive to certain types of ions, so you need very fresh water to make up specific blends of completion fluid that will prevent formation damage. Recycling the water on flow back is probably not economical when looking at the cost of processing plus waste disposal versus just trucking in new volumes from some supplier or pulling it out of a local surface source (lake, etc), or just producing water from a source well that you already have handy. Those supplies may be drinkable, but a high iron content might make it unsuitable, for instance.

Please take all of this with a grain of salt because I have no specific shale gas experience and haven't read any technical papers on specific completion/production issues. All I can say is that completion fluid design is very important and varies from formation to formation if done properly.

The Clays can swell in shales (and most formations). Mostly the type of clay that causes swelling damage is smectite clay. The addition of potassium chloride help prevents this rather easily (or any other clay control agent but KCl is the benchmark). Other damage of clays is migration (when the well is produced to fast, or water is injected too fast) these clays are kaolinite and illite, but pumping fresh water can shock these clays and cause pore throat damage pluging up the well.

For service companies pumping into shales, the design of the frac fluid is not the difficult. Most jobs in shales are pumped with a friction reducer, salt from produced water can affect the friction reducers but most companies should have high salt tolerant friction reducers and have been pumping with produced water/recycled water. The friction reduced water does not help carry the proppant so the only thing carrying the sand is the rate the water is pumped at.

Really when talking about formation damage, from what I've seen. The conductivity of the fracture is much more important than the damage done to the frac face (formation). Think of it this way, the proppant pack in the fracture is the highway and the formation is the on-ramp onto the highway. It is more important in these fracs to create a better proppant pack (highway) than it is the on-ramps to produce gas. But have good proppant pack conductivity and less formation damage is always a good thing.

these shale formations are often dry, but as they dried out over time (geological time) they left a lot of salts behind, so when fresh water is used in the frac, it flows back high in salts which makes the next frac more difficult. But when you frac you only get 30-50% of your water back, so you still have to make up the rest of the water for your next frac.

[Tiger]

Originally Posted by Pinner

I wouldn't think it would be that difficult to filter the water to reuse for fracing ?

Depends are what type of frac fluid you want to use, and what you are trying to accomplish.

Crosslinked fluids are a lot harder in recycled water then just a friction reduced water.

[Pinner]

Originally Posted by Tiger

But when you frac you only get 30-50% of your water back, so you still have to make up the rest of the water for your next frac.

30-50% of the water from the first pad... There are some big drilling projects planned...

[Huntingwhale]

Originally Posted by mikey_the_redneck

Shouldn't we be looking for alternative energy that isn't a fossil fuel? We just don't learn.....

[SebC]

Originally Posted by mikey_the_redneck

Shouldn't we be looking for alternative energy that isn't a fossil fuel? We just don't learn.....

Maybe, but environmentalists hate the best one we already have (nuclear).

Just because NG isn't ideal doesn't mean it's not a good step to take.

[Thor]

I'd support a lot more nuclear plants, to get rid of coal plants.

[Pinner]

Canada not ready for shale gas boom

http://www.theglobeandmail.com/repor...rticle1756636/


FRACTURE LINES:

The drilling and subsequent hydraulic fracturing of 16 wells on one pad in British
Columbia’s Horn River Basin early in 2010 set a record for the shale gas industry.
A total of 274 separate stimulations or hydraulic fracturing procedures – 17, on
average, per well – were completed. This record is likely to be short-lived; in late 2010
or early 2011 Encana Corporation and Apache Canada expect to drill and hydraulically
fracture another 28 wells at two new pads in the vicinity of Two Island Lake. At the new
wells, the companies plan for horizontal wellbore lengths of 2,200 metres – 600 metres
more on average than the previously drilled wellbores at Two Island Lake. The projected
water needed to frack the longer wellbores will be an estimated 2.12 million cubic
metres, an amount that will handily exceed the previous fracking record.

http://beta.images.theglobeandmail.c...es_942842a.pdf

[photon]

Originally Posted by mikey_the_redneck

Shouldn't we be looking for alternative energy that isn't a fossil fuel? We just don't learn.....

Where exactly do you want to look? The laws of physics limit what's possible.

Basically there's solar or nuclear. Fossil fuels are a form of solar energy, as is hydro, wind, and pretty much any other source of energy you can think of.

And then there's nuclear, using the natural materials deposited on/in our planet when it formed out of the solar accretion disc.

That's about it.

[Shazam]

Originally Posted by photon

Where exactly do you want to look? The laws of physics limit what's possible.

Basically there's solar or nuclear. Fossil fuels are a form of solar energy, as is hydro, wind, and pretty much any other source of energy you can think of.

And then there's nuclear, using the natural materials deposited on/in our planet when it formed out of the solar accretion disc.

That's about it.

Anti-matter.

Zero point energy.

[Kybosh]

I vote that we use activists for alternative sources of energy. They seem to have so much excess energy that it's a shame to see it go to waste on stuff like protesting seal clubbing.

[photon]

Originally Posted by Shazam

Anti-matter.

Zero point energy.

HULK SMASH!

[Mad Mel]

Tidal. As long as the moon is still there, it's an eternal energy source.

[photon]

Sure, tidal energy will work until the earth's rotation is 28 days, THEN WHAT!?

[chemgear]

Originally Posted by fotze

as far as shale gas, its not just water, its sand that is needed too.

Shale gas is doing a great job keeping gas prices low too. At least that might be what the board of directors of more heavily weighted gas companies keep telling me.

Seriously though, US rig counts are still running high/just off their records last I checked with the whole "drill the lease or lose it" thing. There was a nice article a few days ago in the Daily Oil Bulletin about gas prices going forward - AECO at the current $3 could/should be something to get used to for a good while.