Unconventional Resources Benefit From Custom Chemical Regimes

Unconventional shale plays are becoming an increasingly important and abundant part of domestic and global production, which greatly increases the need for more environmentally conscious solutions for flowback and produced water. Concerns about the potential for groundwater contamination and wastewater disposal have only strengthened the need for careful selection of more environmentally friendly fracturing chemicals.

A prime consideration for any oil and gas producer is to find the most efficient means of minimizing the impact of its daily operations on surrounding ecosystems.

Traditional methods have called for operators to purchase chemicals from the pumping service. Sold as part of an overall program, these systems are designed to fit a wide range of applications. More and more, companies are looking for tailor-designed chemical programs that provide higher efficiencies with better safeguards to the local environment.

Taking a natural line

One way to alleviate much of the controversy surrounding fracing operations in the world's burgeoning shale market is through extensive planning and analysis to engineer fluid programs on a play-by-play basis.

Multi-Chem's NaturaLine products are engineered and assessed with environmental protection as a prime consideration. The company's main objective is to develop technology and chemistries that provide lower toxicity, reduce exposure, and consequently reduce the environmental risks of production and completion chemicals. The company has found a niche in its chemical design process that gives operators an opportunity to partner in the process of achieving goals for both production and environmental stewardship.

"Multi-Chem's customers have been actively looking for ways to reduce their environmental footprint for years," said Danny Durham, vice president of technology. "Several customers came to us and requested chemicals that would reduce both safety and environmental hazards. We then developed the product line to be proactive to have a full suite of frac additives that would reduce risk in the field. We created a set of standards that served as a ranking system for Safety and Environmental Risk. We share this ranking system with our customers so that they can continually choose products for their operation based on the environmental needs of that area and on the safety standards of their organization."

The company's frac fluid additives are evaluated on safety, toxicity, biodegradation, and bioaccumulation. With improvements in biodegradation and reduced bioaccumulation tendencies in the aquatic environment, this chemical system greatly reduces the potential for exposure over the products' total lifetime. Operators can select chemicals that have improved exposure profiles over more traditional chemistries. Continual evaluation gives operators a consistent and comprehensive basis to consider both toxicity and environmental health effects when making informed chemical selections for their production and completion operations.

"From both a performance and environmental standpoint, it is important to use the right product versus just traditional chemistries," Durham explained. In the case of sulfate reducing bacteria (SRB) formation and gas souring control in fracs it is critical for environmental and safety reasons to use environmentally conscious chemistries and to have a product that performs well in reducing dangerous hydrogen sulfide gas later in the life of the well. An example is that some companies use oxidizing agents (like bleach, chlorine, dioxide, etc.) for SRB control in fracs. "The use of these agents with organic materials in fresh, produced, and flow back water for SRB control has a two-fold negative effect in that it does not provide long term SRB control in the formation. This allows for greater risk of hydrogen sulfide formation, and there is the risk of producing chlorinated hydrocarbons including carcinogenic and mutagenic compounds," Durham said.

During the evaluation process, Multi-Chem's technical experts evaluate the production or fracturing challenge and recommend the most effective products and solutions to meet the need. All recommended products receive a ranking based upon carefully selected environmental and health-based criteria. This information is provided to customers along with pertinent technical and cost performance information. Customers can then independently evaluate and select the products that both demonstrate a commitment to environmental product stewardship in their communities and best meet their operational needs.

The goal is to use frac additives and processes that fully utilize flowback and produced water and maximize water management efforts. These solutions can be used throughout the entire fracturing process and can enhance production operations as well. The company's process provides operators with a basis for system-specific frac or production solutions that can offer due diligence to communities, regulators or partners in environmental protection. The product selection process can be tailored to include both Multi-Chem's Natura-Line criteria and customer-based standards and requirements as requested.

From practice into action

Within the Marcellus, Multi-Chem recently was challenged to control bacteria and scaling issues with an environmentally conscious process while the operator effectively fractured the formation up to 2,100 m (7,000 ft). The company had been deployed by a customer for some time when it introduced its NaturaLine process. The decision was made to use the system in subsequent projects. The chemicals being used were B-8642 and S-2510 T, which were proving to be very effective in controlling targeted bacteria issues and scaling problems.

Multi-Chem and the customer set out to find a more environmentally responsible solution. The operator was fracing using flowback water as well as make-up water that was proving to be highly contaminated with SRB and acid producing bacteria (APB). The waters also were showing potential to precipitate scale.

As is standard practice, Multi-Chem obtained samples of the water to be used for fracturing and ran standard tests to confirm that the waters being used contain SRBs and APBs. Specific biocide testing was carried out on a full suite of products using SRB and APB cultures. One of the NaturaLine biocides was deemed an effective candidate based on an environmentally focused ranking system. This was done by leveraging a new, exclusive chemistry to Multi-Chem rather than increasing activity level and pumping a more concentrated biocide. Similarly, the scale inhibitor was selected based on its environmental ranking through the company's ranking process. The biocide was pumped using a Multi-Chem frac truck on location, as was the scale inhibitor. The company pumped the biocide at less than half of the original rate being used. The scale inhibitor was pumped at the same rate as before, achieving the same results with a more environmentally conscious approach.

Chemicals are typically a small line item on a bill from pump companies. For this reason, operators often opt to purchase chemicals from pump companies to avoid having additional vendor on location. If an operator chooses to use a specialty chemical company, a customized chemical program is developed for that particular operating environment.

"With a NaturaLine customized chemical program, Multi-Chem reviews local environmental standards, characteristics of that particular formation, and operational goals of that customer. Specialty chemical solutions, including NaturaLine products, can have a major impact on an operator's bottom line," Durham said. When applicable, a surfactant is recommended that can increase initial production of the well. Friction reducers, when selected and applied correctly, can reduce surface treating pressures needed to frac the reservoir, therefore reducing the amount of horsepower needed. If an operator selects the appropriate bacteria and scale solutions up front can reduce the amount of preventive maintenance to equipment that will be needed throughout the production phase.