The development of the Environmentally Friendly Drilling Systems (EFD) Scorecard has been ongoing since 2008. The first 3 ½ years focused on reaching a consensus for the various attributes through a series of workshops, meetings and paper exercises.
Field Testing of Dual Fuel Natural Gas/Diesel Engine Performance and Emissions in Oil & Gas Operations
As the oil and gas industry continually seeks ways to cut costs and improve environmental performance, HARC’s Environmentally Friendly Drilling Systems Program is studying the feasibility of replacing diesel with natural gas as a fuel source for modern drilling rigs as part of the “Powered by Natural Gas” research initiative. A recent field study of the dual fuel diesel engines powering a rig while drilling focused on three main objectives:
- Examining the critical operational characteristics of transient load response, natural gas and diesel fuel consumption, and engine exhaust emissions.
- Gathering data that can be used to predict performance of dual fuel for a range of operating conditions.
- Comparison of diesel and dual fuel engines to better understand advantages and limitations in drilling applications.
The challenges of powering remote oilfield operations with reliable, cost-effective and environmentally sound technologies have made natural gas an attractive alternative to diesel fuel. Natural gas available in the field holds great potential for keeping fuel costs down while reducing emissions and improving other aspects of environmental performance.
Dual fuel engines are essentially conventional compression-ignition diesel engines that have been adapted to utilize gas together with diesel fuel, thereby displacing some of the diesel fuel. These engines have the flexibility to run solely on diesel fuel when gas is unavailable, making them reliable and versatile. In addition to dual fuel, natural gas powering dedicated reciprocating engines and turbines for electric power are of great interest for the oil and gas industry. However, just how this new generation of engines and emissions control technologies perform in day-to-day oil and gas operations is not well documented and requires further assessment.
HARC scientists designed and built an intrinsically safe, state-of-the-art Real-Time Emissions Measurement System (REMS), suitable for use in a hazardous environment where hydrocarbon vapor may be present, such as an active drilling or hydraulic fracturing location. The instrument package features a real-time exhaust emissions data acquisition system utilizing Fourier Transform Infrared Spectroscopy (FTIR) and an AVL micro soot sensor. These advanced instruments provide direct measurement of gaseous emissions and soot from engine exhaust. Data generated by this research will not only answer questions about gas-powered engine emissions, but can also be used to develop a more accurate emissions inventory for oil and gas operations.