As produced water management evolves in unconventional oil exploration and production, a transition is developing from waste product to beneficial, reusable product. During this transition the aggregation and storage of produced water become an important first step. Aggregation and storage have also evolved from frac tank storage to impoundments and above-ground storage tanks (AST). Aggregation and storage have led to other challenges, namely water quality management. Over time, produced water can foul quickly, leading to poor water quality and potential odor problems. These issues have created the need for regular pit treatments, including adding oxidizers on a regular schedule. Insufficient mixing and UV degradation of commonly used oxidizers make this a potentially expensive process that isn't always completely effective. A commonly used alternative is aeration.
Hydrozonix offers a portable water aeration system as a low-cost alternative for managing produced water pits and ASTs. The combination of introducing air and mixing prevents bacterial growth, and by increasing dissolved oxygen—a mild oxidizer—sulfides, iron and bacteria are reduced over time. The system can be adjusted to supply more or less air in different configurations to adjust aeration needs as water quality changes.
For semipermanent water storage, permanent aeration systems are not cost effective because they do not provide increases in oxygen uptake when water quality degrades. The portable Hydrozonix solution can augment permanent aeration or supply aeration in semipermanent pits and above-ground pits. In addition, Hydrozonix aeration systems are simple to mobilize, and a variety of sizes are available to meet aeration requirements.
Applications of Hydrozonix Aeration Systems
Pit management and treatment: In-ground ponds and pits can experience changes in water quality as bacteria grows. Portable aeration can eliminate this concern while improving water quality. Long-term storage will inevitably experience bacteria growth, odor problems and potentially hydrogen sulfide formation.
Produced water recycling: Produced water recycling can be made more efficient by using portable aeration as a pretreatment tool. Recycling produced water on crosslink gel fracs can require a homogeneous produced water source. Stratification can make recycling problematic on crosslink gel fracs. Aerating mixers can keep the produced water source blended to remain homogeneous for recycling on crosslink gel fracs.
Iron Oxidation and Real-time Bacteria Test Results
The following graphs are examples taken from tests of Permian Basin produced water over a 7-day period using the Hydrozonix portable aeration system.
For a more technical look at how aeration can improve water quality, download our paper titled “Aeration for Produced Water Management.”