Oil & Gas (O&G) production is the most energy intensive of all industrial processes, consuming about 20% of its output for its own process needs. The energy costs involved in the O&G drilling rig operation can be significantly reduced by efficiently utilizing the natural gas that is currently flared in O&G rigs. Unlike other technologies suggested to achieve this, the uniqueness of our approach lies in the on-site single-step conversion of the natural gas being currently wasted in the rig to synthesize dimethyl ether (DME), an ultra-clean synthetic fuel to partially substitute the diesel that is being used in drilling generators. DME can be blended with diesel up to 25% without exposing the fuel injectors of the generator to excessive wear and early failure, as both the lubricity and the viscosity of the fuel blend are kept within ASTM specifications. Based on the amount of natural gas flared/vented and the diesel fuel required per rig, we estimate that by converting ~16% of the flared/vented natural gas to DME, the O&G drilling companies will be able to keep using the same drilling infrastructure while reducing operating costs and preventing the release of harmful pollutants to the environment.
Approximately 170 billion cubic meters of natural gas is flared/vented in O&G rigs annually contributing not only to a significant increase in greenhouse gas emissions but also to an energy loss of ~$31 billion. In the US, the average amount of natural gas flared/vented per rig is enough to produce 6483 gals/day of DME or the equivalent of 3242 gal/day of diesel. Fuel consumption in drilling rigs is estimated to be between 62 to 83 gallons of diesel per hour, depending on operating conditions, totaling a daily fuel consumption of ~2,000 gallons. With current diesel prices at ~$4 per gallon, the daily fuel costs are ~$8,000 per day per rig. Hence, 100% diesel-powered rigs accumulate a hefty fuel tab of $2,900,000 per year, without considering the additional expenses associated with the transportation of the fuel from the refinery to the rig.
Our idea will allow the construction of highly compact reactor modules that can be easily transported from one site to another, consistent with the business model of O&G drilling companies. The validation of the proposed innovation will produce the following benefits: 1) the reduction of natural gas flaring; 2) significant progress towards the self-sustainability in O&G rigs; and 3) a step forward to attain the long awaited efficient conversion of methane to valuable chemicals.
Thus, the proposed idea represents a very profitable alternative to gas flaring as it produces a clean fuel that can directly replace harmful petroleum diesel with a minimum investment. From an environmental point of view, this solution will be beneficial to everyone, given that particulate matter and other pollutants caused by fuels such as diesel in cities around the world is creating a health crisis claiming tens of thousands of lives and costing hundreds of billions of dollars each year.