Simple, Environmentally Friendly, and Economical Methods to Maximize the Reuse of Produced Water for Frac Operations

Dodd, Mike (TETRA Technologies) | Donaldson, Barry (TETRA Technologies) | Harvey, Yannick (TETRA Technologies)

OnePetro 

Introduction

Even in the current market conditions, there's still a need for large amounts of water to conduct hydraulic fracturing, drilling, and completion operations. As millions of gallons of water are needed for each fracturing operation and with most operations occurring in water-stressed regions, the use of fresh water for oilfield applications is coming under greater scrutiny.

Water flowed back from hydraulic fracturing (flowback water) and in situ ground water brought to the surface (produced water) during production account for large volumes of “dirty” water generated by the oil industry. According to the Department of Energy (DOE), produced water accounts for an average of over 60 million barrels per day.1 This water is tainted by various chemicals and/or has natural compositions that, in most cases, render it unsuitable for human consumption, dispersion into nature, or even reuse in the oilfield. Historically, the only way to dispose of this produced water has been to re-inject it into the ground by using salt-water disposal wells.

As water conservation initiatives and the tightening of regulations concerning the use of fresh water become more prevalent, the need to come up with ways to recycle the water already “in the system” becomes more appealing. Operators requiring large amounts of water are looking to produced water for their fracing operations as a solution.

The trend to reuse produced water is being enabled by advancements in mechanical and chemical treatment techniques and the introduction of new fracturing chemical systems that accept high levels of chloride and other chemical concentrations. These technological improvements have opened the way for alternative, economically viable techniques for maximizing the reuse of water in fracturing operations.

Water Infrastructure

The use of produced water makes both economic and environmental sense, as it reduces the need for fresh water and the subsequent cost of trucking and disposal. If fresh water is used for fracing operations and all the produced water is injected into the ground, operators incur trucking, disposal, and storage costs, along with costs to acquire fresh water. With an average cost of $.75/bbl for fresh water and disposal costs ranging from $.50-$2.50/bbl, it makes economic sense to reuse produced water.