Next Generation Zero Emissions Oil Production Facilities & Field Gas Conditioning
Field Gas Conditioning for Frac Fleets
Use of diesel and CNG as fuel sources for hydraulic fracturing is expensive, logistically complex and carries a high environmental impact. In many cases, conditioning field gas to provide fuel for frac fleets is a viable solution to these challenges.
On-Site Natural Gas Fuel for Hydraulic Fracturing
Hydraulic fracturing fleets are used today to unlock the hydrocarbon resources found within shale, the “source rock” of oil and gas formations. These frac fleets include a large number of pumping units, used to generate high pressure fluids that are directed downhole into the formation in order to frac the shale. The pumping units can be driven by a number of different prime movers, including diesel engines, natural gas turbines, or electric motors (which themselves are most often powered by an engine or turbine). Providing the energy required to keep these prime movers operating is typically a logistically complex proposition, requiring a continuous train of transports to deliver diesel fuel or compressed natural gas (CNG) at great expense. Of course the burning of diesel fuel (as opposed to gas) and the transport of either fuel to the site also results in significant emissions.
Reduce Diesel Costs with Field Gas Treatment
To start to combat these issues, many diesel driven frac fleets have been, or are now being converted, to run in a dual fuel mode. This allows them to substitute diesel with lean, cleaner burning and less expensive natural gas. CNG is viewed as a good alternative to diesel, and many fueling companies are now providing CNG delivery to serve this need. However, delivered CNG can still be quite expensive and retains the logistics and emissions footprint from transporting the fuel to the site. By the time source gas costs, compression, trucking, the high capital cost transports themselves, and pressure reduction skids (which include pressure reduction, regulation and heating) are included, costs can approach that of delivered diesel fuel.
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Meanwhile, most pads already have a gas midstream connection built out to them by the time the wells are being fracked, ready to accept associated gas from the pad right from initial production. Gas is already flowing through this midstream line from the surrounding wells. Could this gas be used as a readily available fuel source for the engines? It could be, however this is raw associated gas which presents a number of challenges for use as fuel.
Challenges of Raw Field Gas
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Low-quality fuel in untreated form
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High levels of heavy (C3+) hydrocarbons
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Presence of water and condensables
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Inconsistent composition, pressure, and temperature
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Can be unsuitable for engine use​
Impact on Performance & Value
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Engine derating and reduced efficiency
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Increased downtime and maintenance costs
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Higher emissions
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Lower diesel substitution rates
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Lost revenue from unrecovered NGLs and condensate
Field Gas Conditioning Equipment is the Solution
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What is needed is a field gas conditioning system to remove the water and heavy hydrocarbons and provide consistent lean gas output that is a high-quality fuel for the frac fleet, along with an optional NGL or condensate output for additional revenue generation. Millions of dollars in frac fuel costs can be saved per month through such an approach, in addition to simplifying logistics by taking a great number of fuel delivery trucks off the road.
​Pioneer Energy provides several Pegasus field gas conditioning systems that can meet this need. The Pegasus LP is well suited to field gas conditioning for Tier 2 fleets, while the Pegasus Dream is ideal for use with both Tier 2 and Tier 4 dual fuel engines, as well as gas turbines and natural gas generators.
Features of Pegasus Field Gas Conditioning Systems for Frac Fleets
High Performance – Able to accept a wide variety of raw field gas compositions, the Pegasus will provide a lean, consistent (composition, pressure & temperature), continuous output of high-quality fuel gas, enabling the highest possible diesel substitution rates. The system will autonomously adapt to changing raw gas supply and fuel gas demand, requiring little to no ramp up time, and it is able to keep up with the most demanding frac stages. Most importantly, the equipment has been designed to never slug the engines.
High Capacity – Pegasus units, either stand alone or in parallel, can provide whatever fuel gas volume is required by the particular frac fleet technology and number of pumps present.
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High Availability – Proprietary software and robust hardware enables high availability, which greatly improves economic return and is essential for mission critical oilfield applications.
Robust Construction – Built tough to withstand rough oilfield environments and the punishment of regularly occurring deployments and redeployments.
Highly Mobile – Pegasus systems can be skid or trailer mounted with quick and easy disconnects. They are designed to travel with the frac fleet from site to site. With appropriate planning and staging; teardown, transport and setup can be achieved in less than 24 hours.
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Liquid Return or Optional NGLs – All Pegasus units can return a liquid residue to a return line (if available). Depending upon configuration, some Pegasus units can also stabilize NGLs onboard, providing the flexibility to produce a truckable Y-grade product if desired.
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Autonomous – Leveraging Pioneer's sophisticated control software, each Pegasus unit is designed to be easy to operate with simple push button controls, minimizing the required attention of field operations personnel.
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Cloud Enabled – Real time status and diagnostic information provided from the onboard SCADA system is made available via cellular, local area network, or Starlink connection and stored in a secure online data historian for future reference. Customer or Pioneer technicians can log in for remote configuration, monitoring & control, and status and alerts can be set to automatically push to relevant stakeholders via text message and email.​
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​​Additional Functionality – Fuel filtration, heating & gas manifolding can be provided through the addition of a separate stand-alone module (Field Gas Filtering, Heating & Manifolding Skids), or can be incorporated onboard.​
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Safe – Built for full compliance with all relevant oilfield equipment standards, including all ASME code stamped vessels and Class 1 Div 2 compliance, each Pegasus unit design has also been subjected to a rigorous HAZOP process. The Pegasus unit can be connected on each site with the customer's systems for permissives and emergency stop controls.
