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Chevron Fracking: Drill Cutting Repurposing Engineering Design 100 Section 20
Team 3 (Frackalicous) 12/4/16
(From left to right) Dylan Shoemaker ([email protected]) Michelle Kotarsky ([email protected])
Sam Connors ([email protected]) Rohan Soni ([email protected])
Table of Contents:
Executive Summary………..…………………………………….……………...1
Introduction and Problem Summary………………….………………………..1
Definition of Sustainability..……………………………………………….…….1
Background……………………………………..……………………...………...2
Customer Needs….......................................................................................2
Concept Generation…………………………………….…………….………….2
Concept Development and Selection (Prototype)......…………….………….3
Cost Analysis……………..……………………………………………………....3
Description of Final Design……………….………………………….………….4
Description of Prototype……………..……………………………….………….5
The analyses we performed ……..………….………………………………….6
Systems Diagram……..…………………..….…………,……………………….7
How the product improves current solution.…………..…………….………...7
Design based on Chevron’s requirements.……………..………….….……...7
Economic viability of the system.…………………………………...….……….8
Impact on sustainability.…………………...……....…………………...…….....8
Impact on the environment.…………………………………………….…….....8
Impact on regulations and safety.………………………...…………………….8
Impact on the schedule/cycle time).……………………………..…….…........9
Conclusion……………………………………………………………………..….9
Appendices………………………………………………………………………11
References………………………………………………………………………12
Executive Summary: This design project outlined by Chevron worked to produce a viable and
sustainable alternative use for the drill cuttings produced as a byproduct of the fracking process. Numerous concepts were generated after researching different methods of disposal and reuse of the drill cuttings produced as a result of fracking. Each concept was then roughly screened based on basic customer needs such as feasibility and sustainability. After narrowing down the concept list, four concepts remained which were scored on a weighted scale. The winning concept from this scoring matrix involved using the cuttings for a cement aggregate. Doing so would significantly lower the price of filling the wells once their lifespans expire. Furthermore, the filling-infused cement could even be used to construct new projects off of the worksite.
Introduction and Problem Summary:
The purpose of this project is to develop a more efficient use for the drill cuttings produced as a result of fracking other than simply relocating them to a landfill. The innovative solution needed to incorporate certain considerations regarding sustainability, regulations, safety, costs, timeliness, and transportation.
On average, a typical fracking site will produce 10,000 ft^3 of drill cuttings per well. (the equivalent of a 10 story building with 1,000 ft^2 floors filled with drill cuttings). The current practice dealing with drill cuttings is to haul them off-site and dispose of, without any purposeful secondary uses.5 These waste drill cuttings are simply sent to landfills to rot, which can often produce leachate. The hazardous effects of the leachate produced have been well-documented in the facilities where the drill cuttings are sent to decay.
Frackalicious envisions a future where the drill cuttings resulting from the fracking process are reused in some efficient form. In this design project, Frackalicious sought efficient methods of reusing drill cuttings the fracking produces. The environmental effects, social implications, and economic barriers were studied to design a solution. Ultimately, the goal of Frackalicious was to repurpose or recycle all drill cuttings produced from fracking in order to find an appropriate replacement method.
Definition of Sustainability
To be sustainable means to meet the needs of society today without diminishing the ability of future generations to meet their needs. Sending the waste cuttings to landfills does in fact meet the needs of society today, but will become detrimental to the environment over time. In this project, we tried to reach sustainability by designing a process that reuses or recycles the drill cuttings instead of disposes them.
Background Fracking is a multi-step process in which a solution (made of mostly water, some
chemicals, and sand) is pumped into the ground, at high pressures, to force open natural fissures in order to extract the oil and natural gas that lies within the earth. This process starts with finding a viable oil/natural gas source and laying out a pad in which the entire plant will lie. After bringing in the needed machinery, the drilling process will begin.
A large drill is used to cut down into the earth vertically and horizontally to reach these fissures. This step requires an input of energy and labor and gives an excess of drill cuttings (that may or may not be radioactive), to which they currently dispose of in landfills. Once the drilling process is done, the next step is to pump the solution into the wells. The solution is used to keep the fissures open, so the oil and/or gas can be extracted. After the extraction is done, the fracking company then fills the wells, packs up the site, and moves on to the next project.
Fracking is a very controversial topic because many believe the process’s negative results outweighs the positive results. With a little research and innovative thinking we could perhaps satisfy the negatives and fracking will become more accepted within the community.
Customer Needs
Our customers will be the public, construction plants, local residents, and industrial firms. Each of these customers require sustainability (no radioactive cuttings), reserve the right to know how deep potentially radioactive materials are, and whether they will be extracted from the fracking process.
This would include the absence of radioactive materials that could potentially serve as a detriment to the surrounding environment and local residents in the area. Moreover, the fracking company would have to establish a clear agreement with customers as to how deep the radioactive drill cuttings would be placed. Cost efficiency is also an important consideration for the customer base. On-site and off-site treatments would affect the cost and should be optimized in order to maximize efficiency. Additionally, the transportation of drill cuttings and other byproducts of fracking would play into the economic aspects of the customer’s demands. Concept Generation
Instead of developing a single design, a good amount of time was allotted to concept generation in order to maximize our final results. Inspirations for many of these concepts included current models and practices, our customer needs, the requirements and considerations stated by Chevron, and our creativity. Some ideas overlapped and
others seemed underdeveloped, so some were combined and others scrapped. After this initial analysis, quite a few concepts remained that required further screening. For an in depth look at the various concepts we generated and how we came to them, see Appendix B. Development and Selection (Prototype)
After comparing the range of rating for the different concepts we came up with, we decided to stick with the highest ratings, deeming them more necessary for our system.
Table 1: Concept Screening Matrix
It turned out that using the drill cuttings as a cement was our best, or highest rated, concept to use. We decided that putting the cuttings back where they came from would be smart and efficient since it could be done on site (collection, grinding, storage, mixing, and filling).
Cost Analysis
When we were determining the final cost of our project, we had to consider several different elements. We used our system diagram as a reference for calculating the cost, in which the first step was drilling. The drilling cost would be null, since the only cost incurred would be from setting up the machinery and the labour on-site. Next, we moved to the grinding cost, which would largely be covered by Chevron and their on-site equipment. The only cost we would incur would be from transporting this machinery to and fro from the fracking site, which would be approximately $1800. Collection and storage were the next factors we had to evaluate, the materials for which
Chevron would provide but we would have to transport.3 The cost of mixing the drill cuttings with cement would be our heaviest, since we would have to take into account the machinery as well as transportation costs - the final figure being approximately $101,800. To supervise all the activities on-site, our team felt that we would require at most five workers, who would be paid $25 per hour over the course of six months (duration of a fracking experiment) for five hours a day. These workers would maintain efficient usage of running machinery on-site as well as take care of the electrical costs, which would be around $5000 total. Lastly, we calculated the indirect costs we would have to cover, such as tolls and warehousing. Since all our materials would stay on-site and be transferred once the fracking process finished, we wouldn’t have to pay for any warehousing. However, toll costs were estimated to be around $90. Finally, our total costs added up to be approximately $190,000, which can definitely be reduced if we re-estimate some of our variable costs such as labor. Overall we feel this is a realistic figure to undertake our project. For an in depth look at the cost calculations, see Appendix A. Description of Prototype
During the early stages of our project, we brainstormed ideas for what our model would look like, and created a simple drawing shown below. This drawing highlights some of the features such as the cement plant, grinder, drill and filler.
Figure 1: Early drawing of our model
Once we had discovered what our objective of our project was, we wanted to build a physical model to represent our ideas. The model needed to include every
feature that an actual model would have such as the drill, grinder, storage tank, cement plant/ mixing plant and filler. To reciprocate our ideas into our model, we first started off creating the fracking site with the help of a foam board shaped like a cuboid with an open ended face. Next, we created a replica of a drill with the help of chopsticks, and a foam board as the foundation. Moving on, we used an empty inverted cut out soda bottle as our storage tank. The drill and storage tank were connected by tube wrapped by paper, better known as the grinder. The most essential part of our model, the cement plant, was represented via a cuboidal foam board structure with a mini-tube on the top. Lastly, we used aluminum foil to display our fillers, which would pump the cement back into the ground once it was ready. Our team was quite satisfied with our final product, which looked quite compact, aesthetically appealing and projected the message of our team effectively. Top View Right View
Front View Isometric View Figure 2: Finished Prototype: Top, Front, Right, and Isometric Views
Description of Final Design (3D SolidWorks Model)
Top View Front View
Right View Isometric View Figure 3: Solid Works Model: Top, Front, Right, and Isometric Views Figure 3 above shows the finished design of our model. The model includes the
original drill (red), grinder, storage silo, and cement plant. The grinder is attached to the drill so that the cuttings may be fed through it upon surfacing. There they will be ground into finer cuttings and immediately stored in the silo. When time comes, the fine cuttings will be moved to the cement plant and to eventually be used to plug the well. The analyses we performed
One of the analyses we conducted was to determine whether or not we would have any excess cement remaining to be buried into the landfills once the entire process was finished. After taking into account the average amount of space the cement would consume, as well as the average amount of drill cuttings extracted during the process, we concluded that we would have some cement left over. This cement could be transported to other sites where the cement could be used as a weak aggregate with another material, because the strength of a cement combined with drill cutting hasn’t yet been discovered.
● Systems Diagram
Figure 4: Systems Diagram
● How our product is improved compared with the current solution Current Solution: drill cuttings are hauled off of the fracking site to landfills to be disposed of, without any purposeful secondary uses.5
Possible Alternatives: ● One company proposes to relocate its processing facility to the airport grounds,
where it would pay to lease the land, then use the cuttings to extend the runway by 600 feet. The processing building will eventually be turned over to the airport for use as a hanger.4
● Reuse as construction material on polluted former industrial sites, known as brownfields.
● Research: In 2011, Clean Earth got the permit to do research and development to examine the beneficial re-use of drill cuttings. The idea is to do something with it, rather than send it off to a landfill. Clean Earth takes the muddy cuttings that come out of gas wells, mixes it with cement, and tests it, before placing it old, polluted industrial sites, or brownfields.4
Our Solution as an improved product: When wells are ready to be abandoned, they are filled with cement and pipes cut off 3-6 feet below ground level. Our team plans to take advantage of this process by incorporating the drill cuttings. Cuttings will be collected on-site to later be made into the cement that goes into filling the original drill when time comes. The resulting product will reduce waste sent to landfills and cut the current cement costs since much of the material will be gained on-site (drill cuttings), instead of being purchased and delivered.
● Assessing our design against Chevron’s stated requirements Requirements stated by Chevron: Come up with an innovative way to reuse/repurpose/recycle the drill cuttings. Considerations should be made for sustainability/environment, regulations, safety, cost, schedule/cycle time and transportation of the material.
Our initial design concepts were created to ensure that the drill cuttings are recycled in some way. Many designs seemed viable at first, but the radioactivity of the cuttings made this hard to execute. After some assessment, we concluded that each of Chevron’s requirements and considerations could be met if we sent the drill cuttings back where they came from. To do this, we would mix them into cement to fill the pipeline, which would double as a substitute to the current drill filling process (cut costs) and waste disposal practice (higher sustainability, less economic impact). This solution, in turn, will require waiting for the fracking process to be completed before the pipes can be filled. We accommodated this consideration by having a storage container on site to store the drill cuttings until the cement production process is ready.
● Assessing the economic viability of the system The bulk of our system’s total cost will determined by construction and
transportation costs. The three main additions to the fracking site will be the grinder, a machine that will cut the drill cuttings into smaller additives for cement production, the storage silo, a container for storing the fine cuttings, and the cement plant, which will mix the cuttings into cement for well plugging. However, because a great deal of our design relies on the fracking process itself, much of cost will be incurred by Chevron or entirely not included. The drill cuttings, for example, will be collected from the drill during the drilling process, and the plugging of the well will be done by Chevron. With the incorporation of the fracking process in mind, our system will be economically viable.
● Assessing the impact on sustainability
The impact our system will have on sustainability will be two part:
1. Reduce waste sent to landfills. Reducing this aspect will allow for landfills that would have been filled with fracking waste to be filled with other kinds of waste. In doing so, the needs of today will be met since the drill cuttings are being recycled while simultaneously boosting the needs of tomorrow (less waste sent to landfills means increased total landfill space).
2. Provide and ensure proper sealing of wells. Properly sealed wells can reduce, if not eliminate, cross flow and potential threats that an improperly sealed well may have on public health and safety, and the quality of the groundwater resources.
● Assessing the impact on the environment
Our system envisions to reduce, or even diminish, the negative impacts that improperly abandoned wells may pose on the environment. For example, certain threats may arise from the failure to plug a well before it is abandoned or plugging it poorly such as contamination of surface water entry (minerals, bacteria, waste, etc.), surface leakage from shallow zones through well, leaking cement sheath, or leakage from an aquifer to surface.7 Our system will ensure that cement plugs are placed before a well is abandoned to avoid such threats on the environment.
● Assessing the impact on regulations and safety Current regulations: The Water Well Drillers License Act requires that the owner or consultant who is to abandon the well notify the department of the intent to decommission a well at least 10 days before the well is sealed or filled. Individual department bureaus may have specific regulations or guidelines. In addition, the Bureau of Oil and Gas Management is responsible for regulating the plugging of oil and gas wells.6 Disregard of regulations: Despite past and current regulations, many drillers will simply walk away from their wells once the oil and natural gas cease to flow. Even with laws requiring drillers to pay a bond to ensure that they will not simply walk away from the well, the drillers will choose to default over plugging their wells. Such bonds, researchers warn, are woefully inadequate and actually provide an economic incentive for drillers to abandon their wells without plugging them. Doing so will cause them to forfeit their bond, which is generally less than $10,000, but this is no comparison to the cost of plugging each well, which could cost $100,000 or more. In sum, the temptation to cut corners is powerful. It is still nonetheless harmful Last year, for example, research by a doctoral candidate at Princeton University concluded that abandoned gas wells are responsible for between 4 and 13 percent of all of the human-caused methane leaks in Pennsylvania.6
Implementing our system to every fracking site will make sure that any regulation concerning the plugging of wells is met by ensuring that each well is plugged with cement before it is abandoned.
● Assessing the impact on the schedule/cycle time)
The system would have almost no effect on the schedule/cycle time for the fracking process as it does not interfere with it. However, the on-site cement mixing plant could lower the time it takes to fill the wells once the fracking process is done by several days. Typically, fracking sites have cement trucks come in and pipe cement down into the well but having a plant on site would lower the cost of transportation and the time it would take to fill the wells back up. All in all, by implementing an on-site cement system, the fracking sites could save multiple days for each cycle of fracking, thus making them more efficient. Conclusions
This real-world project helped to further develop the skills of aspiring engineers. By completing each and every phase of the product development process, there were many lessons learned. Many gained exposure to the future of technological advances which they will be dealing with for the rest of their careers. Teamwork skills were also developed by each team member by working with each other on a daily basis. By using concept generation skills that were developed through taking the Engineering Design course, the team was able to generate a list of concepts and ultimately chose a final design.
The final design was selected since it was very sustainable, incorporated low transportation costs, and was relatively easy to implement. Some of the major drawbacks to this design were its high initial cost of construction and its potential energy consumption. The cement plant and storage silo would add additional costs to the typical fracking site, which in the short run could raise the price of operation. However, this system would save Chevron money in the long-run by decreasing the cost of filling the wells after the conclusion of the fracking process. Additionally, the energy costs to operate the cement plant would be trivial in the long for a company of Chevron’s size.
Even with the large initial cost of the construction of the cement plant, the reusability of the design proves allows this to become less of a concern for Chevron. Since the major components of the system are able to be reused again and again at multiple fracking sites, the construction costs would not be a major issue. This illustrates the importance of reusability and sustainability of processes in the modern industrial world. As energy becomes more of a scarcity, companies will need to continue to develop creative ways to be efficient and sustainable in their methods of energy
production (and consumption). Ultimately, the benefits outweighed the drawbacks for this concept, allowing the group to produce a successful and integrative system. In the end, this efficient and sustainable design will pave the way for similar eco-friendly innovation in the future of the industrial world.
Appendices Appendix A: Cost Analysis
Appendix B: Concept Generation Flowchart
References:
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