Concrete Retention Pond

Chevron

Engineering Design 100 - Section 013 Instructor - Sarah Ritter Ph. D

December 6, 2016

Impractical Roasters Joseph Cioffi - jhc5269@psu.edu Nam Bui - nbb5200@psu.edu

Aaron Gruber - acg5413@psu.edu Rachel Rizzardi - rir5145@psu.edu

Executive Summary:

Horizontal drilling and fracking is the most widely used method for harvesting natural

gas. Chevron uses these methods and is one of the top suppliers of natural gas. Two problems

they face at every drill site is how to dispose of the rock chippings and how to more efficiently

store the millions of gallons of water the process uses. The Impractical Jokers developed a

solution that takes the rock clippings, tests to make sure there are no hazardous rocks mixed in,

makes the chippings into concrete with the used water and sand mixture, and makes the retention

pond out of concrete which is covered by a large pool cover. This solution covers all of

Chevron’s design needs such as being more environmentally friendly, safe, cost efficient, waste

efficient and not taking up as much space. To develop initial ideas, a classification tree for the

design criteria was created. After that, bad ideas were drawn out to identify qualities that should

not be included in a good design. Sometimes good ideas also come from this activity, or after

that in the activity devoted to good ideas. The group used a concept scoring matrix and AHP to

narrow down the initial ideas two the strongest two: selling the chippings as art supplies and the

concrete retention pond. After building a prototype, the concrete retention pond was chosen as

the best design. This plan may not be the most environmentally friendly or use the least amount

of space but for each of the client’s needs it is tremendously better than the current model.

Introduction and Problem Statement:

When companies such as Chevron use hydraulic fracking in the extracting of natural gas,

they produce some waste products. Two of the main waste products that come from the fracking

process are water and rocking cuttings. Usually Cheron does away with the water and puts the

rock cuttings into a landfill. This is simply not an efficient way to deal with the waste products.

The Impractical Roasters wanted to find a way to use both of these waste products in a way that

recycles them and makes them available for use in another fracking venture.

The design solution must be a situation where we create less waste from fracking. A large

part of this waste is the tons of rock cuttings. There is also a lot of water needed and problems

with storing it.

Now there is have a large amount of waste from fracking and water to store as well. Space in

landfills is largely taken up by rock chippings and this material could be used for another

purpose.

This problem afflicts Chevron and the cost the of the gas it produces because they could

lower the price if they were more cost efficient. This effects everyone buying gas. This problem

of water, inefficiency, and lack of storage cause an increase in price and a high negative impact

on the environment. It is important to fix the problem to increase revenue in the company,

decrease consumer costs, and decreases the environmental impact.

Definition of Sustainability:

The Impractical Roasters believe that any solution that is considered should be based on

the group’s definition of sustainability. Any design solution should solve a problem by being

productive while minimizing impact to the environment and thinking about the needs of future

generations. In the case of Chevron, the design solution produced for them should have minimal

impact on the environment while recycling the waste products. The solution should also not have

any negative effect on Chevron’s productivity. In fact, Chevron should eventually profit from the

Impractical Roaster’s design.

Background:

To store fresh and flowback water that are used in the fracking process, Chevron has been

using the lined water pit solution which has the risk of leaking and the toxic gas from flowback

water can cause respiratory problem. (1) (2)

Chippings that are created during the fracking process are being disposed without any

method of recycling. Some of the chipping may contain radioactive material that can cause

nuclear pollution. (3)

Customer Needs:

The team chose 5 main criterias for the project which are: Environmental Friendly,

Waste Efficient, Cost, Good use of Space and Safety.

Table 1. AHP Matrix

After we finished the AHP Matrix (Table 1), Impractical Roasters decided that the most

important criteria is safety because that is Chevron’s top priority and because the main purpose

of this project is to make sure the process of fracking is safe for the people and the environment.

Our team then ranked good use of space second because it is also really important that all

of the equipments will not take too much space on the site. Next to that is environment friendly

which is what we want to improve in this project. Efficient is second last because this project is

still in its early stage so we want to make it work properly before making efficient. The team

ranked cost lowest because for the project of this scale, high cost is inevitable, at least at this

stage of the project.

Concept Generation:

The first activity was think of really bad ideas. The goal was to identify all of the

undesirable qualities for the design, so when brainstorming good ideas, those qualities were not

included. Sometimes there were good ideas brainstormed during the bad idea part because the

team was thinking more creatively. The initial ideas included making concrete, selling the

chippings to art stores, using them as landscaping, using them as fertilizer, disposing of them in a

body of water, send it to space, and make it into road asphalt as shown in figures 1, 2, and 3. The

group went through the ideas and decided to move forward with the concrete and art ideas

because they were the least wasteful. The first idea, making concrete with the chippings and

waste products of the drilling, was chosen after another side idea was proposed. The concrete

could be used in another part of the fracking and solved a second problem with water storage.

The art idea was kept because there was a profit for the company and would make the process

more cost efficient because it also cost to throw the chippings in the landfill like they do now. A

classification tree for our design criteria was also considered in the decision making shown in

figure 4.

Figure 1 - Page 1 of initial designs.

Figure 2 - Page 2 of initial designs.

Figure 3 - Page 3 of initial designs.

Figure 4 - Classification Tree Concept Development and Selection:

In deciding which idea to move forward with in the design process to the prototype stage,

the Impractical Roasters used a number of factors. The group had to decide between using the leftover rock cuttings for art supplies or using them in the manufacture of concrete for a retention pond. As discussed earlier, The AHP matrix was used to determine which characteristics of the design were most important to the effectiveness and productivity of the final design. The Impractical Roasters chose safety as their top priority and that really followed by space efficiency and environmental friendliness as seen in the AHP matrix below. Once it was decided which characteristics were most important, group 2 also looked at their concept selection matrix. This helped determine which design solution was most effective in the most important categories.

AHP Matrix

Concept Selection Matrix

Both design solutions had a good amount of pros and cons. The art supplies design was

completely “green” but probably wouldn’t be as profitable for Chevron. There is not a huge market for small stones. The retention pond solution was also “green” and was a good use of the waste products from fracking. There were very few if any drawbacks to this solution. Among the groups members, it was agreed that the retention pond was the best course of action because it was just going to be a lot more useful for Chevron in the long-run. As seen in the concept selection matrix, the srt solution scored very well but in the end the Impractical Roasters stuck with the concrete retention pond. The solution had a lot to offer Chevron and had a very minimal impact on the environment. This was the design that the Impractical Roasters would move and create a prototype for. Description of Prototype (Prototype):

Figure 6. The chipping grinder and concrete mixer

Figure 7. The entrance to the chipping grinder

Figure 8. The concrete mixer

Figure 9. The retention pond

Figure 10. Retention Pond with concrete liner

The model is a great representation of how the final design looks like. It has all of the important components that allow this system to work. This design will allow the team to safely dispose the chippings thanks to the hazardous material testing process after all the chipping has been grinded out. The whole system was designed to be compact so space efficient is maximize. All of the machines have metal shells outside to prevent any type of leakage thus making them really safe for the environment. The grinder and concrete mixer are linked together by a conveyor to maximize time and power efficient. Description of Final Design (3D Model):

The final design would consist of taking the drill cuttings from the fracking site. They would be tested and then grinded down into an acceptable size for concrete. Then gravel, sand from the previous dig, and water will be added together to make concrete. The retention pond will be dug out and then covered in a layer of concrete to replace the liner used in current retention ponds. Then the pond can be filled with water to be used in the next dig. The systems diagram:

This is more effective than what Chevron does today. Chevron currently digs trenches

and throws a plastic liner down and stores all the water there. However, with the Impractical Roasters retention pond, we will be reusing all of the excess materials to design a more stable in ground pond. The size of this pond would increase productivity because it would be able to hold enough water for the entire dig, and also reduce our environmental impact because there wouldn't be a need to dispose of excess materials, and it would also eliminate the need for a thick plastic liner.

The requirements for Chevron were that we had to recycle drill cuttings in an appropriate manner, while considering costs, environment, safety, time and transportation. The design effectively recycles the drill cuttings into concrete. It would decrease costs for Chevron, because there wouldn't be a need for a plastic liner, and most of the materials used for the concrete would be reused drill cuttings and water. It would help our environmental impact because we would be disposing of the drill cuttings, and there wouldn't be a need to dispose of the plastic liner. The concrete retention pond is also safe, because the design includes testing the drill cuttings and making sure they are safe to put into the concrete.

Transportation costs wouldn’t increase, instead of transporting the materials to a dump site, they would just bring them to the next drill site. The amount of time it would take to set up would increase compared to the plastic liner, however, Chevron would have the ability to take the chippings directly from the current site to the future site and begin setting up the next retention pond.

The concrete retention pond replaces the thick plastic liner. Making the liner creates carbon dioxide and adds chemicals to the environment. Making concrete creates some carbon dioxide but not near as much as plastics. Concrete is cheaper than plastic in this case because all

we need to purchase is the cement. The cost to install the liner is $650,000 and to dispose of it would be another $10,000. The only part of this cost the retention pond would have is digging and filling the hole. In addition, disposing of the chippings is $100 per ton and disposing of the water from the hydraulic fracking is seven dollars per barrel. Both of those disposals would no longer be costs. This design is more sustainable than plastic and would take the same time to set up as plastic. Concrete is used in most construction so it is completely safe. Conclusions:

Overall the concrete retention pond design decreases the waste out-up and saves Chevron money. It will increase the efficiency of fracking but making the concrete will increase environmental impact. From this point Chevron could decide which of the 170 types of concrete would be best for this project and make the process even more efficient with a smaller environmental impact. The team learned how to deal with more design freedom. In past projects there was a product the client was already using and the goal was to improve it, not make a new product. This limited the possible solutions and did not allow for as much creativity. The out of the box thinking led to the solution of not one, but two of Chevron’s problems. References:

(1) https://sites.psu.edu/engineeringdesignproject/files/2016/10/ESSGN-100-FA16-Chevron-Project-21reqdo.pdf

(2) https://www.nrdc.org/media/2014/141216

(3) http://grist.org/business-technology/fracking-produces-tons-of-radioactive-waste-what-sh

ould-we-do-with-it/