Porosity and Permeability Lab

Earth Science Extras

past Russ Colson

Water Well on the Plains of Kansas, on the subcontract where I grew upwards. I of my chores was to open up the wind vane and release the restriction to water the cattle after schoolhouse!

Online learning can capture some aspects of doing science as a practice--some elements of arguing from show, elements of explaining models or applying those models to solving problems or explaining phenomena. Still, 1 of the hardest aspects of science as a practice to include in an online feel is the actual doing of experimental or observational scientific discipline. In a existent lab, you have to figure out what to do, y'all take to effigy out what to observe, you lot have to figure out what those observations tell you lot about the universe. When the lab is given to you every bit in an online experience, you are told what to do and even what yous are supposed to notice. This limits the lab experience to only the concluding pace of interpreting the results. To give you equally much lab-similar feel equally possible, you should not only scout the post-obit videos, just record the primal data in writing, and then interpret the results. You volition need the information to complete the following questions and to sympathize the lab.

Measurement of Porosity--effect of different types of sediment

Picket the experiment below, recording all data. Don't make sloppy recordings--record values carefully, including proper units of measurement, and organize the data into a table or chart that you tin easily read and interpret.

Ideally, you can see the experiments in the videos beneath and create your own data table. However, to encourage you to take the time to do a good job with this lab, I provide example data tables for you lot to print and fill out in the file Preparation_for_Porosity_and_Permeability_experiments.pdf

Video of porosity measurments

Although the video does not show repetitions of the measurements, for the following puzzles, assume that multiple repetitions reveal that the two-sigma experimental dubiousness in the measurements is near plus or minus 10% relative, pregnant, for example, that, for a measurement of l% porosity, the 'true" value has a 95% chance of being between 45% and 55%.

For the following questions, yous must do the information analysis based on the information that you accept taken from the video and written down in a table. Exercise not repeat these questions to become better answers--get them right the first time. Although repetition has been a valuable excercise in the previous interactive texts, it does non provide a meaningful learning experience in this instance where the purpose is to practice interpretating and manipualting data, not getting a right answer.

Measurement of Permeability--upshot of different types of sediment

Watch the experiment below, recording all data. Don't make sloppy recordings--tape values carefully, including proper units of measurement, and organize the data into a tabular array or chart that yous tin can hands read and interpret.

Ideally, you can see the experiments in the videos below and create your own data table. Nevertheless, to encourage you to take the time to do a proficient task with this lab, I provide example data tables for you to print and fill out in the file Preparation_for_Porosity_and_Permeability_experiments.pdf

Video of Permeability Measurements

Remembering our formula for discharge in basis water from the previous part of this lesson (reproduced below), calculate the permeability for each of the sediments (in Darcies). Darcy is the unit of permeability when the area, altitude etc are in units of centimeters (or square centimenters, equally appropriate), and the force per unit area difference is in atmospheres. Note that a cubic centimeter and a milliliter are the aforementioned volume.

Q= Discharge (in cubic cm per second) = P (in Darcies) * A (in square centimeters) * f (in atmospheres) / L (in centimeters)

Solving for Permeability gives us the following:

P (in Darcies) = [Q (in cubic cm per second) * L (in cm)] / [A (in foursquare cm) * f (in atm)]

You need to get all of the values from the experiment in the video, which you should accept already compiled into a chart or tabular array-- except that I take done the calculation of the pressure change for y'all. The pressure at the bottom of the sediment is i atmosphere and the pressure at the top of the sediment is ane atmosphere plus the weight of overlying water. The average pressure drop is virtually 0.0172 atm.

Make sure y'all have the calculations correct--don't reply the following questions until you're sure. Have you calculated A (area) correctly? Bank check the formula for surface area of a circle if you demand to. Have you calculated Q (belch) correctly? When you're sure, answer the following questions. These questions are worth more points and y'all shouldn't expect to go back and "right" them.

Understanding Experimental Design

concluding updated ix/13/2022.   Text and pictures are the belongings of Russ Colson.