【系列專題】頁巖油生存有道：水處理的奧妙（3）

REPORT IDENTIFIES AND QUALIFIES SALTWATER RISK FACTORS, TRENDS

The EnergyMakers Advisory Group is publishing a comprehensive 300-page metastudy that identifies and qualifies the complex risk factors and recent trends associated with the oil and gas industry’s operational reliance on Class II saltwater disposal wells for the safe and effective disposal of produced water, fracturing water and approved oilfield liquid wastes as well as protection of U.S. drinking water sources. There is a complex array of conflicting information surrounding use and regulation of underground disposal wells, often with politically driven undertones. In an even-handed, fact-based manner, The EnergyMakers Advisory Group explores these underground injection control (UIC) issues at a macro, regional and local level supported by detailed maps, relative risk weighting factors, and charts and indices allowing operators to identify those assets and UIC formations with higher relative risk that may bear more detailed exploration or risk mitigation. The coverage universe includes a deep dive into each of the leading onshore U.S. basins covering basin and region-specific injection, seismicity, formation health risk indicators, scientific underpinnings, regulatory and litigation landscapes, operations continuity and best practice considerations, region-specific opportunities for risk reduction, and new investment frontiers.

TOOLS REDUCE WATER MANAGEMENT COSTS

Veolia has developed ShaleFlow, a cost-effective mobile system for treatment and reuse of flowback and produced water from hydraulic fracturing operations. This compact, transportable system incorporates proven technologies in a three-trailer configuration with the flexibility to be moved as the field is developed. ShaleFlow can treat up to 10,000 bbl/d and accept a wide range of influent water quality containing up to 300,000 total dissolved solids. The system removes particulates and scale-formers to low levels, generating water quality suitable for reuse in fracturing and completion operations. Water treatment and reuse reduces freshwater demand, recovers oil from produced water and minimizes produced water disposal costs. Another Veolia product released this year is the CoStrip degasifier. CoStrip effectively removes dissolved gases such as BTEX (benzene, toluene, ethylbenzene and xylene), volatile organic compounds, CO2 and H2S without the need for pretreatment. Typically installed as part of a treatment train that enables surface water discharge, CoStrip minimizes the capex and opex costs of the overall system. Its effective operation reduces chemical and sludge costs when paired with chemical softening and extends the life of reverse osmosis membranes.

BUILD SALTWATER DISPOSAL FACILITIES FASTER WITH LOWER OVERALL COSTS

The Victaulic Refuse-to-Fuse joining system for high-density polyethylene (HDPE) pipe is a line of small and large-diameter couplings, fittings, transitions and accessories that can join SDR 7 to 21 HDPE pipe up to 10 times faster than fusion—the common method used in connecting water and slurry HDPE lines. The Victaulic system eliminates the need for fusion, providing a faster, simpler joining method that can be used in a variety of applications including flowlines, water transportation, fracturing ponds, water treatment, saltwater disposal and facility construction. Produced water transportation and disposal costs can represent half of a shale well’s operating expenses and is one of the biggest challenges facing an operator’s bottom line. To put a lid on these costs, operators are building their own production and water disposal facilities instead of relying on third-party waste management companies. Victaulic’s HDPE system is helping shale operators build saltwater disposal facilities faster with lower overall installed costs. The couplings can be easily installed in vertical orientations as well as in tight spaces using simple hand tools and can be reused from site to site. Victaulic’s Refuse-to-Fuse system has been successfully deployed by major operators in several shale plays, including the Permian and Eagle Ford.

SHALE FLOWBACK FLUIDS TREATMENT ELIMINATES PASSIVATION

Electrocoagulation (EC) treatment for shale play well flowback fluids dates back to the early 2000s. Its role is the heartbeat in many flowback fluid treatment processes. It breaks emulsions and reduces insoluble and soluble hydrocarbons, heavy metals, suspended solids, organics and bacteria concentrations at efficiencies exceeding 98%. Traditional EC methods, however, have a problem— passivation. This detrimental challenge causes oxide scale or coating buildup on the system’s electrodes, adding significant costs in manpower, power consumption, efficiency and disposal. Passivation can quickly cause treatment efficiency degradation and shutdown for costly electrode (plate) cleaning or replacement. Water Vision Inc. has developed a proprietary ThinCell EC technology that completely eliminates passivation. The technology uses sacrificial electrodes consisting of a common waste product that are completely consumed and efficiently replenished without costly unit downtime. There is no need for electron/ plate removal for cleaning (acid wash or grinding) or replacement. Passivation elimination preserves the necessary electrical amperage for the cell operation, lowering power requirements and usage. ThinCell technology increases uptime, reduces maintenance and lowers both costs and safety risks. Because of its technology, the ThinCell has a small footprint and is available in a variety of mobile configurations and flow rates from five to greater than 500 gal/ min.