Natural Gas as a Fuel in Drilling Operations-Analysis, Testing and Implementation

Abstract

Abstract Utilizing natural gas as fuel to power large engines is not a new technology; however the application of dedicated natural gas powered engines to power drilling rigs can be considered a new approach to environmentally and socially responsible operations in the oil and gas industry. The use of dedicated natural gas engines on drilling rigs provides the opportunity to capture the following advantages: reduced emissions reduced cost improved maintenance characteristics, and improved for domestic energy security. Barriers to adoption of this technology application for drilling operations included low cost of diesel, certainty around diesel handling and performance, uncertainty on natural gas engine performance under variable load conditions, impact of variations in gas composition on engine performance and operational challenges related to bringing natural gas to the rig in remote operations. This paper describes the process used to evaluate, test, implement and measure the application of dedicated natural gas drilling systems in the Jonah Tight Sands drilling operations in Wyoming and in the Haynesville Shale Gas operations in northern Louisiana. Key learnings from deployment of natural gas engines in the field will be shared. As part of the technology application process, dedicated and dual fuel engines were tested and different forms of natural gas fuel sources were utilized based on maturity of the field, proximity to natural gas infrastructure and natural gas quality. This included utilization of lease/field gas, treated gas (tailgate of gas plant) and liquefied natural gas. The evaluation process included the following: engine performance, engine emissions, natural gas quality, cost differential when compared to dieselburning engines, planned maintenance costs versus diesel and life cycle analysis. Evaluation results will be summarized along with economic analysis. A decision tree model was developed to assist in evaluating when to consider natural gas as a fuel in drilling operations and what adaptations to the application would be required to respond to various forms of natural gas available for use. The model will be applied to an emerging natural gas field in Europe or Asia.