【系列專題】頁巖油生存有道：水處理的奧妙（2）

TECHNOLOGIES IMPROVE WATER MANAGEMENT, TREATMENT PROCESSES

Gradiant Energy Services offers several technologies, including free radical disinfection, selective chemical extraction and carrier gas concentrator for water management and treatment. Free radical disinfection provides short-term kill for disinfecting water with no hazardous chemical handling. The treatment uses salt, water and electricity to generate a mixed solution that provides effective bacteria kill of sulfate-reducing bacteria and acid-producing bacteria. The treatment is a mobile system that treats water on the fly up to a rate of 120 bbl/min. The technology allows operators to ensure that the water pumped downhole and reaching the reservoirs is properly disinfected and treated. Proper disinfection eliminates the long-term problems that can occur from bacteria growth, H2S and corrosion. Selective chemical extraction is a treatment that takes produced and flowback water and recycles the water back to a clean brine reusable for fracturing operations. The technology uses a patented algorithm to develop the chemical dosaging along with a patented lamellae clarifier. The system is designed to treat 10,000 bbl/d in a modular capacity. In addition, the carrier gas concentrator is an evaporation system that runs off of the operator’s field gas to reduce the volume of water the operator is handling on location, significantly reducing trucking cost. This system also is mobile and reduces water volume by using a humidification process. The amount of particulate matter released in the vapor is minimized through the patented technology, the bubble column. The evaporation unit can evaporate about 1,000 bbl/d.

PROPPANT REDUCES PRODUCED WATER AND INCREASES PRODUCTION

Hexion’s AquaBond proppants, available in 20/40, 30/50 and 40/70 mesh sizes, are an advanced resincoated sand. These proppants use a resin chemistry that reduces the production of formation water compared to traditional proppants while maintaining oil and gas production. This increases the profitability of the well by reducing wastewater storage and disposal costs. The AquaBond proppant’s Stress Bond proppant technology delivers all of the benefits of a curable resincoated proppant, including proppant flowback control, reduction of proppant fines generation, minimization of proppant embedment and enhanced well production, compared to traditional proppants. AquaBond proppants also increase hydrocarbon production, as shown in a recent case study. Results yielded a 36% hydrocarbon production increase over traditional proppants in offset wells in the Granite Wash Formation after 12 months. These proppants are helping operators reduce water, maximize well profitability and lower cost per barrel of oil equivalent. These proppants are being used in multiple basins across North America where minimizing water production is essential. The cost savings to operators combined with the enhanced production will yield improved returns.

TREATMENT SEPARATES HYDROCARBONS FROM FLOWBACK AND PRODUCED WATER

Water recycling and/or disposal is becoming increasingly important in unconventional production due to the massive amount of water involved in completion and production processes. Locus Bio-Energy Solutions LLC has developed a patent-pending microbebased clarification treatment specifically designed to separate hydrocarbons from flowback and produced water. This environmentally friendly technology has applications in both water recycling and in disposal well injection of produced water. The company’s product can rapidly demulsify entrained hydrocarbons and destabilize solid suspension impurities such as scale and sand, allowing them to immediately separate out of the brine. The hydrocarbons can then be mechanically recovered to add to oil sales volume while impurities are filtered out. The treatment is nontoxic and easy to implement.

HORIZONTAL GUN BARREL REPLACES MULTIPLE OFFLOAD TANKS, TRANSFER PUMPS

National Oilwell Varco’s (NOV) horizontal gun barrel offers significant benefits to operators beyond IOR. Designed to be more efficient than traditional or enhanced vertical gun barrels, the NOV horizontal gun barrel is engineered with fracturing flowback and saltwater disposal in mind. Already being adopted in the Permian Basin and Marcellus Shale, a single horizontal gun barrel replaces multiple offload tanks, gun barrels and transfer pumps. The horizontal orientation recovers far more oil with less residence time than a typical vertical gun barrel. Increased hydraulic fracturing activity is leading to more solids in the wellstream, which can mean frequent tank cleanouts. This problem can be eliminated with NOV’s proprietary Tore solids fluidizing technology, which quickly and efficiently removes solids from the horizontal gun barrel without disturbing the separation of oil and water. The horizontal gun barrel also is featured in NOV’s optimized saltwater disposal process, which is designed to deliver better water quality at lower cost and produce cleaner, drier oil. Combined with NOV’s WaterWolf dynamic oil recovery system and desanding skid, the complete suite offers a more efficient option for water recycling.

TECHNOLOGY EFFICIENTLY REMOVES NONSOLUBLE ORGANICS AND INORGANICS

OriginClear’s Electro Water Separation (EWS) technology efficiently removes nonsoluble organics and inorganics such as free and dispersed oil and suspended solids from produced water. The system uses electricity and nondonating anodes to break the oil/water emulsion and coagulate and float suspended solids and oils to the surface of the water so that they can be easily raked off for recovery or simplified disposal. In a recently added final stage called Advanced Oxidation, the electrical fields already generated remove dissolved contaminants such as ammonia, H2S, metal ions and other chemicals that are hard to remove from influent water. Throughout the process, Advanced Oxidation kills bacteria and oxidizes most heavy metals as well as many miscible and dissolved organic contaminants. The combined technology, EWS:AOx, is modular, energyefficient, continuous and easy to manage. It fits right into any water treatment process and works ahead of filters and membranes to improve final water quality and increase the lifespan of all water treatment equipment. EWS:AOx has been demonstrated to remove 99.9% of turbidity and reduce suspended solids and hydrocarbons to below detection limits on produced water from Colorado gas wells, West Texas intermediate wells, and Monterey and Niobrara formations.