Weighing the pros and cons of oil and gas wellfield electrification can be a challenging process. Approaching these decisions in an orderly and systematic manner can deliver results that meet operational needs.

Here are five basic factors that must be weighed when launching a study or in preliminary discussions for a wellfield electrification project.

1. Power Need

The density of wellfield assets is key to determining what types of electrification options need to be considered. Will the load add up to 1 megawatt (MW) to serve assets spread over 100,000 acres, or will it be 500 MW spread over 3,000 acres?

This profile will determine whether electrification investment should be directed toward high-voltage transmission or a lower-voltage distribution infrastructure.

Geospatial information on the wellfield layout will provide many of these answers. Where are well locations and delivery points? Where are the major pipeline corridors and processing facilities?

2. Power Quality

A relatively dense wellfield will create some differences in the need for equipment regulating and controlling power quality.

Will there be a number of large motors, drives or devices that create harmonic distortions? With these units frequently starting and stopping, 60 hertz cycles can be pulled out of optimal wave lengths for a condition sometimes known as dirty power.

Multiple solutions are available, including options to scale the load up or down, depending on projected need. If load may ramp up or down frequently between 100 MW and 200 MW, will it be necessary to overbuild for that type of surge capacity?

If the load will be highly variable over two or three years but then relatively stable for years afterward, some power quality issues can be resolved with filters or other means of voltage support. Those hurdles can be crossed easily, but only if identified early.

3. Timing

If the electrification plan is needed within two to three months, it is unlikely a detailed study can be completed. However, this may not be needed initially if the plan is intended for a high-level executive briefing or Wall Street review.

Still, a lot of preliminary data can be quickly assembled. What are the plans for the various wellfields? What type of maps are available? There may be many areas where we need to sharpen our pencils and fine tune the data.

We can forecast the number of transformers and miles of wire needed as production ramps up to certain thresholds. If $100 million is available to spread over all assets over a given number of years, the timing of production will dictate levels of investment. Those decisions affect how elements of the plan are prioritized. Typically, these budgets to electrify production operations should be developed to deliver the biggest bang for the buck, focused on speed to market.

4. Derivative Metrics

Though there may be certain portions of the wellfield that can be more easily connected to reduce costs, those steps still may not deliver significant environmental benefits. Even with improved operational efficiency, it is entirely possible that early improvements may not move a significant volume of Scope 1 direct emissions to Scope 2 indirect emissions generated from the wider power grid. In fact, it may be possible for producers to go further than the Scope 2 criteria defined under internationally recognized Greenhouse Gas (GHG) Protocol standards.

This aspect of the analysis can be aided greatly with derivative metrics that look at the benefits that may result from certain inputs, investments or activities. For example: what MVA (megawatts/voltage/amperage) benefit can we expect per dollar with a $1 million investment in efficient transformers and control devices? What greenhouse gas reduction can we expect from investing in more efficiency?

Derivative metrics give a clear picture of what should be prioritized because they create a quantifiable matrix of variables that tell the producer what outputs can be expected for this amount of investment.

These metrics can aid in understanding goals of both capital and operational expenditures. Are there ways to decrease operations expense over time by investing a little more upfront in capital expenditures? An analysis of derivative metrics might also justify moving money toward annual operations budgets — away from upfront capital — if long-term operational needs indicate that is where it needs to be.

5. Power Supply

How does the producer want to get its power? If significant megawatts are coming from power purchase agreements, are there renewable energy credits available? If the production basin is in a wind resource area, it might be prudent to build a wind farm or some other form of renewable generation.

Once a direction on power sourcing is established, a lot of resources can be evaluated.  

Planning the Way Forward

Planning for any kind of wellfield electrical infrastructure should generally start with these five factors. That helps you determine the correct path forward. If you want to decrease operations expense by kicking up capital investment levels, a whole range of options arise, affecting timelines and allowing decision-makers to prioritize spending differently.

 

Though wellfield electrification can be a complex process, win-win options are available.

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by
Omar Urquidez, PE, Ph.D., is the utility consulting department manager for 1898 & Co., part of Burns & McDonnell, in the firm’s Houston office. With more than 15 years of energy industry experience, he consults with a range of clients on utility consulting solutions including transmission and distribution planning, generation and load interconnection support, NERC compliance, and economic project justification and prioritization.