Low Emissions Microgrid Power Fueled by Bakken Flare Gas

It is estimated that 30% of the over 1 billion cubic feet per day of natural gas produced in the Bakken shale field is lost to flaring. This flared gas, were it to be collected and used in DLE power generation gas turbine engines, represents approximately 1.2 GW of collective electric power. The main reason that much of this gas is flared is that the infrastructure in the Bakken lacks sufficient capacity or compression to combine and transport the gas streams. One of the reasons that this gas cannot be utilized on-site for power generation is that it contains significant amounts of natural gas liquids (NGLs) which make the gas unsuitable as a fuel for natural gas-fired gas turbine engines. A Lean, Premixed, Prevaporized (LPP) combustion technology has been developed that converts liquid fuels into a substitute for natural gas. This LPP Gas^tm can then be used to fuel virtually any combustion device in place of natural gas, yielding emissions comparable to those of ordinary natural gas. The LPP technology has been successfully demonstrated in over 1,000 hours of clean power generation on a 30 kW Capstone C30 microturbine. To date, 15 different liquid fuels have been vaporized and burned in the test gas turbine engine. To simulate the vaporization of NGLs, liquids including propane, pentane, and naphtha, among other liquids, have been vaporized and blended with methane. Emissions from the burning of these vaporized liquid fuels in the test engine have been comparable to baseline emissions from ordinary natural gas of 3 ppm NOx and 30 ppm CO. Autoignition of the vaporized liquid fuels in the gas turbine is controlled by the fraction of inert diluent added in the vaporization process. The LPP technology is able to process an infinitely variable composition of NGL components in the fuel stream by continually adjusting the amount of dilution to maintain a heating value consistent with natural gas. Burning the flare gases containing NGLs from a well locally, in a power generation gas turbine, would provide electricity for drilling operations. A microgrid can distribute power locally to the camps and infrastructure supporting the drilling and processing operations. Using the flare gases on-site has the benefit of reducing or eliminating the need for diesel tankers to supply fuel for power generation systems and equipment associated with the drilling operations.