The "horsey ride" of frac sand testing
Published: Thu, 10/03/13
Last night I was trying to get my younger daughter moving in the
general direction of bedtime.
Motivating a 3-year old to get ready for bed commands the best of
my persuasion skills.
We were at step 3 of the 5 step bedtime process, which was going to
the dining room for the quick (hopefully) bedtime snack.
We needed to go from her bedroom, where she had just put on
pajamas, out to the dining room.
She requested a horsey ride to make the journey.
As a gesture of my good will towards her proceeding down the
bedtime pipeline, I obliged and gave her a horsey ride all the way
out there.
Halfway out to the dining room, I realized that these horsey rides
must be really fun to get.
I don't remember them much from my childhood, because you
can't be too old or you get too heavy for most dads to give a
ride of any distance.
She really enjoyed the ride, anyway, and steps 3 through 5 of
bedtime went pretty slick.
Point is, for me the crush resistance frac sand test is the
"horsey ride" of testing.
Yes, the weighing out of the sand is an exacting and demanding,
sometimes painful process. You see, you have to be precise on the
mass to 3 decimal points.
A grain of sand weighs about 1 mg, so you are literally adding or
subtracting grains to nail the mass.
Anyway, once you get the sample mass completed, it's pretty
darn fun.
First, you load up the test cylinder with sand.
In our lab we use a pluviator, which is a column about 2 feet tall.
The pluviator makes sure that you get a very level surface of sand
in the pressure cell.
You pour the sample in the top of the pluviator, and it goes
through 2 different screens to make the sand "rain"
evenly down into the test cylinder.
Now, you have the cylinder ready and it contains about a half inch
of perfectly level sand.
You place the piston carefully into the cylinder, so that it rests
on the sand.
Then you rotate the piston 180 degrees to ensure it evenly contacts
the sand.
You place the cylinder and piston combination into the press.
I use a manual press in my lab. There might be some labs with
automated presses, but we like to "kick it old school"
here, and it's allowed the test procedures.
Now, I start to ramp up the pressure in the press, which pushes
down on the piston, compressing the sand.
The pressure is ramped at 2,000 psi per minute, and then when you
get to the maximum pressure for the test, you hold the pressure for
2 minutes.
Once that 2 minute hold time is up, you take the sand in the
cylinder out and run it through the sieve.
Now, you will have some crushed sand fines make it all the way to
the sieve stack pan. This you weigh.
You divide the mass of the fines by the overall mass of the sample
you used, and VOILA.
You have the percentage of fines for that pressure, and that my
friends is the crush resistance test.
The "horsey ride" of frac sand testing.
I offer horsey rides for free to my daughter.
You are not quite so lucky. Heh.
However, it's still a heckuva deal for you to get crush
resistance testing done on your sand.
It's included in my package deal of API testing, for $1,950.
That's our 2013 price. 2014 will see an increase.
Later.