压裂液耗水多、成本高？WaterSure药到病除

With the average fracturing stage using about 158,300 gallons (3,769 barrels) of water and an average of 30 stages in a well, you likely use about 4.75 million gallons (113,100 barrels) of fresh water per well. Once used downhole and returned to the surface, it is wastewater that requires treatment and injection in an underground storage well. You repeat this process for
every well.

At Weatherford, we think there’s a more efficient way to operate. That’s why we designed the WaterSure™ fluid system. It enables you to fracture using produced or flowback water—without sacrificing performance.

Reuse your wastewater as a key ingredient in stimulation fluids that perform reliably in a variety of downhole conditions, while conserving the local fresh water supply and reducing your costs. Once all suspended solids and bacteria—which could inhibit fracturing performance and damage your well— have been filtered from your produced water, we add an environmentally friendly gelling agent and crosslinker. The result is a clean, low-residue stimulation fluid that is unaffected by flowback additives and can handle waters high in salinity, total dissolved solids (TDS), divalent ions, and boron. WaterSure fluids imitate the conductivity and permeability of fresh water, which protects formations from damage.

Tool Description

The WaterSure® fluid system enables fracturing with 100% produced or flowback water—either filtered or unfiltered—without sacrificing stimulation performance. When freshwater supplies are limited or water quality is inconsistent, use of the WaterSure system conserves freshwater supplies and reduces water costs.

The system adds an environmentally friendly gelling agent and crosslinker to any available water at your wellsite. The result is a low-residue stimulation fluid that is unaffected by flowback additives and can handle waters high in salinity, total dissolved solids (TDS), divalent ions, and boron. WaterSure fluids imitate the conductivity and permeability of fresh water, which protects formations from damage.

This graph shows WaterSure fluids operating in 100% unfiltered produced water. WaterSure fluids maintain high, closely controlled viscosity levels that are sufficient to carry proppant over long periods of exposure to high temperatures.

Applications

• Locations where freshwater sources are limited, where obtaining • consistent;
• water quality can be problematic, or where water conditioning is not an available or cost-efficient option;
• Bottomhole temperatures ranging from 110°F to 300°F (43°C to 148°C);
• Water with up to 400 parts per million (ppm) of boron, 307,000 ppm of total dissolved solids (TDS), and 30,000 ppm of divalent ions;
  Water with unlimited levels of chloride and salt.

Features

• WaterSure fluids can incorporate all types of water: fresh water and unfiltered or filtered produced or flowback water. Operators can use up to 100% produced or flowback water, and filtering suspended solids from the water is optional;
• Three additives enable optimal fracturing performance: crosslinker, pH leveladjuster, and gelling agent. As a result, WaterSure fluids are unaffected by temperature fluctuations, flowback additives, and changes in water quality, such as switching between fresh water and produced or flowback water;
• Chlorine dioxide (ClO2) can be added to WaterSure fluids to eliminate bacteria that can sour wells and to improve the permeability, wetness, and porosity of formations.
• WaterSure fluids are unaffected by ions that suppress gel hydration, which reduces hydration time;
• The gelling agent is formulated to yield higher viscosity levels using a lowerweight polymer compared to standard crosslinked fluid systems;
• WaterSure fluids are compatible with a wide range of chemicals;
• Non-sensitivity to shearing prevents WaterSure fluids from breaking down prematurely when motion is applied;
• An ammonium persulfate breaker enables WaterSure fluids to break down in controlled intervals based on well temperature and the pounds of breaker used;
• Tests indicate a high level of regain permeability (more than 84%)—a low risk for formation damage— after using the WaterSure system.

Benefits

• Conserves the freshwater supply for more environmentally – friendly fracturing;
• Eliminates the downtime, logistics, costs, and fuel consumption associated with transporting fresh water;
• Reduces wastewater disposal and the need to drill and maintain storage wells;
• Decreases completion costs by recycling produced or flowback water and by using only one crosslinker and a low-cost, conventional gelling agent;
• Reduces filtration requirements;
• Performs reliably in diverse downhole conditions;
• Imitates the conductivity and permeability of fresh water, and therefore maintains the same level of fracturing performance that operators achieve using 100% fresh water.

The WaterSure Fluid Treatment Process

1.Filter Suspended Solids

We understand that you may not have the necessary equipment to filter produced water at your job site, so we’ve teamed up with Omni Water Solutions. With minimal to no chemical treatment, the onsite Omni system filters from produced water all suspended solids that can hinder fracturing performance, and the system clarifies water down to the 15-micron to submicron level. Because interfering ions, salinity, boron, calcium, and chlorides have no effect on WaterSure fluid performance, their removal is unnecessary, which reduces your treatment costs. The filtered waste can be disposed of in an environmentally safe manner.

2.Oxidization

Without any harm to the environment, the addition of chloride dioxide (ClO2) to filtered water kills bacteria that can sour your well while helping to decrease reservoir pressure and improve the permeability, wetness, and porosity of the formation, which can increase production rates. ClO2 won’t affect the pH balance in your well or react with most organics and ammonia. We choose ClO2 as a biocide because the U.S. Environmental Protection Agency (EPA) recognizes it as a powerful yet safe water disinfectant per the Safe Water Drinking Act (SWDA) of 1974.

3.Ready for Stimulation

We combine filtered water with an environmentally friendly gelling agent and crosslinker to create fluids with excellent proppant transport and conductivity. WaterSure fluids handle salt concentration in excess of 300,000 parts per million (ppm), between 5,000 to 30,000 ppm of divalent ions, and greater than 400 ppm of boron and 185,000 ppm of chlorides. Additionally, the fluids perform well within temperatures from 100°F to 300°F (38°C to 149°C). With the addition of our specialized crosslinkers, WaterSure fluids maintain high, closely controlled viscosity levels that are sufficient to carry proppant during long periods of exposure to high temperatures and bottomhole pressures.