(364c) A Mass Integration Model between Hydraulic Fracturing Processes and a Power Plant

Energy consumption keeps increasing drastically due to population growth and economic development. Therefore, there has been a great interest in emerging energy sources such as unconventional gas and renewable energies. Consequently, natural gas has increased significantly its consumption (24%) in the last decade until 2017, and it is considered the main substitute for oil and coal as the leading future energy source in the next 20 years. Therefore, a great amount of research and development efforts have been established in recent years about the use of natural gas in different sectors including industrial, domestic, electrical, transportation, and some others. As a result of the recent innovations in horizontal and hydraulic fracture, shale gas has become an important global energy supply. Shale gas is obtained through hydraulic fracturing best known as fracking, which is a technique for shale gas and oil extraction from unconventional reservoirs, generally shale formations. This process demands a huge amount of water, which is used as a fracturing fluid, to accomplish the releasement of the shale gas. However, the problems associated with high water consumption and disposal provoke serious concerns in terms of possible adverse impacts and also, they have created the necessity of sophisticated strategies for water management. In this context, this work represents an alternative to reduce freshwater consumption through CO₂ capture coming from power plants to be employed as a fracturing fluid. The use of CO₂ as fracturing fluid is an alternative to partially replace the fresh water or even completely.

This project proposes a mathematical programming formulation to synthesize water and CO₂ networks associated with the shale gas hydraulic fracture operations while taking into account the fluctuations in the system (water availability, generation of CO₂ and the flowback water based on a horizon time). The proposed formulation incorporates a strategic planning that minimizes the total annual cost (TAC) considering water requirements, generation and capture of CO₂, as well as the capacity of the equipment for treatment technologies, transportation fees, storage units, and disposal. An example problem is presented to show the applicability of the proposed methodology. However, it is very important to mention that there are currently no previous studies that implement a rigorous optimization approach for the use of a water-carbon dioxide mixture as fracture fluid. Therefore, the innovation of this work focuses on the development of a mathematical programming model for the optimal management of water and CO₂ to be used as fracturing fluid in shale gas wells, which represents a very important tool for the zones with significant water scarcity.