Evaluating the Transition to Natural Gas-Powered Equipment in Hydraulic Fracturing: Challenges, Benefits, and Feasibility Analysis
Authors: Hollaway M. , Aune R. 
Published: January 2025

Abstract
The transition to natural gas as a primary fuel source in hydraulic fracturing operations launched in 2013 with the introduction of dual fuel engines, which use a blend of diesel and natural gas. This transition remains ongoing, marked by two fundamentally different approaches to displacing diesel with natural gas. Initially, dual fuel engines emerged as the pioneering technology for substituting diesel with natural gas on hydraulic fracturing jobs. These engines are still being used and improved upon today. Subsequently, circa 2018, companies began developing and deploying 100% natural gas-powered generation systems to drive electrically powered hydraulic fracturing equipment.
Historically, gas powered generation has been found exclusively in stationary applications. Adapting this technology to a mobile package for hydraulic fracturing operations has been a formidable industry-wide challenge. Unlike stationary setups, mobile deployment necessitates considerations of weight, ambient outdoor conditions, and the reliability of the natural gas supply. Prior to equipment construction, weight optimization is imperative, as off-road mobile units are subject to state-specific road weight restrictions. Compliance with axle, king pin, and total weight limits is mandatory for roadworthiness. Moreover, the lack of control over outdoor ambient conditions further complicates mobile deployment. Unlike ambient conditions, natural gas supply is within control of the operator, though it cannot be preemptively resolved like weight considerations. Post-deployment, natural gas quality and supply often emerge as predominant challenges, highlighting their significance in mobile gas-powered generation for hydraulic fracturing operations.
The balance of transitioning to natural gas fueled engines, while the natural gas infrastructure catches up, has been both delicate and complex. Diesel has been used as a fuel source for over 70 years in the industry and thus has firmly established a robust supply chain. In contrast, the Compressed Natural Gas (CNG) supply chain is in the early stages of development and has consistently served as a bottleneck for deploying natural gas technologies. However, there is a prevailing belief that the inherent benefits of natural gas will act as a catalyst for the evolution of the CNG supply chain in the years to come.
Considering the ongoing challenges, it is imperative to evaluate the true benefits of this transition. Assessing whether the opportunity cost outweighs the hurdles encountered, both presently and in the foreseeable future, is crucial. This paper aims to address this critical question by leveraging empirical data collected during the initial stages of our organization's natural gas transition. Through a comprehensive analysis, we examine the tangible advantages and potential drawbacks of embracing natural gas technology, providing insights into the feasibility and implications of this transition for the hydraulic fracturing industry.
In this analysis we will focus on Tier IV Dual Fuel engines, Gas Reciprocating Generators which produce electricity to drive electric frac pumps, and Gas Reciprocating Engines that mechanically drive the hydraulic pump. The baseline for comparison is established using Tier II Diesel engines. Each technology will be evaluated based on multiple criteria including emissions, cost savings found in both fuel purchases and operating costs, and overall operational considerations. Through a combination of Original Engine Manufacturer (OEM) data and empirical data, this paper provides valuable insights into the efficacy and feasibility of transitioning to natural gas-burning equipment in the context of hydraulic fracturing operations.