Sean Halloran, Vice President, Wellsite Technology, Ensign Energy Services
Smart grid technology is acknowledged as a key facilitator for modernizing the electrical distribution infrastructure. There are many examples of data analytics combined with new instrumentation and equipment that illustrate the benefits that smart grid technology brings to generation, transmission and distribution companies. As an end-user, these improvements have enabled opportunities to rework what was typically left to on-site temporary generation for power requirements in the drilling rig industry. Well construction for O&G, geothermal and carbon sequestration utilizes large drilling rigs which require 4-5 MW of on-site generation to operate, usually provided by diesel-powered generators. These rigs move around from well to well and pad to pad (new processes are driving batch drilling where multiple wells are drilled from a single ‘pad’) within a geographical area. Rigs may be stationed on a well/pad for as little as a week or as long as a year plus with the average time to drill a well at around a month. This mobility and the remote locations which are often at the endpoint of branch distribution networks has made a grid-tied solution for rig power difficult and costly. In addition, drilling rigs have notoriously bad power quality with power factors often falling below 0.5 due to the transient characteristics of the load. This often necessitates expensive PF correction strategies and can delay bringing these grid-edge users online.
Ensign Energy Services is a leader in developing and deploying hybrid drilling rigs where grid-scale batteries coupled with energy management software can enable grid-tied operation. In combination with smart grid technology developed for the transient renewables generation on the distribution grid, we can now reliably run drilling rigs from medium voltage provided at the edge. This is both an opportunity on the customer side to take advantage of consistent power delivery and an opportunity on the utility side to unlock a previously isolated revenue source. The number of drilling rigs operating in the United States is just under 1000, with around half of those located in the West Texas/New Mexico energy play known as the Permian Basin. The total power needed is around 2 GW, or about 3% - 5% of the total grid-connected demand in the ERCOT region, making this an industrial potential demand on par with the projected utility-scale electric power sector solar photovoltaic (PV) capacity scheduled to come online in Texas.
"As the well construction market moves to a factory model, a resilient, reliable power source will enable what has previously been a small niche customer to take advantage of financial and operational benefits in addition to the ‘social license to drill’ benefits"
When used in grid-tied installations at the edge of distribution networks, these battery energy storage systems (BESS) installations and the high power electronics (inverters) required to synchronize with the grid can provide compelling financial as well as operational benefits for the well construction process. Peak shaving for a variable transient load can account for a significant percentage of the cost on a monthly basis, and for larger installations, the BESS sizing may allow for load shifting where rate structures allow this as well as participating in storage initiatives for grid support. On the operational side, improved power quality can reduce expensive capital repair costs and more importantly, reduce rig blackouts, which can severely impact rig operations
These benefits are well known and documented for traditional industrial grid customers. As the well construction market moves to a factory model, a resilient, reliable power source will enable what has previously been a small niche customer to take advantage of financial and operational benefits in addition to the ‘social license to drill’ benefits. Wells for O&G and geothermal can be situated in close proximity to neighborhoods and can even be found in the middle of urban centers. Drilling rig operators will need to be good neighbors and removing the large diesel gen-sets from the well construction site is a good first step to maintaining relationships in the community.