Associated Shale Gas- From Flares to Rig Power

Abstract

From September 2011 to July 2013 the percentage of flared associated gas produced in the Bakken shale formation decreased from 36% to 29%. Although the percentage decreased, the volume of associated gas produced has almost tripled to 900 MMcf/D, resulting in the flaring of approximately 266 MMcf/D. The Bakken area is one of the most produced shale oil and condensate formations in the US. Reported volumes for this formation suggest that the amount of associated gas flared is enough to power drilling and hydraulic fracturing operations.

This research shows the technical feasibility of replacing diesel for powering drilling and hydraulic fracturing operations in the Bakken formation with flared associated shale gas. We show that this is a more efficient solution to powering drilling rigs and hydraulic fracturing equipment while also reducing the amount of gas being flared in shale oil and condensate plays producing associated gas. To do this, we investigated the composition and volumes of gas being flared and the average energy requirements for drilling rigs and hydraulic fracturing equipment in the Bakken area. The investigation reveals that the amount of associated shale gas being flared is more than enough to supply the energy required for power to the drilling rig and frac spreads. After reviewing power sources that can use natural gas (including turbines, dual-fuel, and dedicated spark ignited engines) and associated gas separation technologies, we are able to make recommendations for the best use of flared associated shale gas.

We show that making the switch to natural gas from diesel can result in cost savings for drilling rig and hydraulic fracturing operators. Natural gas costs less than diesel and is more environmentally friendly.