The demand for more efficient, effective, and environmentally acceptable hydraulic fracturing solutions will continue into the future as shale reservoirs play more of a critical role in meeting the rising energy demand. The measurement of success for tomorrow’s wells will not just be improved operational efficiency and initial production, but will include long-term well performance and reduced environmental impact. Operators and service companies must remove the uncertainty associated with conventional hydraulic fracturing techniques and aim simply to generate the desired number of fractures while ensuring that proppant is placed accurately to achieve good conductivity for the life of the well. Some of the disadvantages of conventional well stimulation methods include the following: Uncertainty of the number of fractures initiated within cluster perforations.Uncertainty of proppant distribution along multiple fractures.Proppant schedules designed to avoid screenout and not provide optimum conductivity.Overflushing of the near-wellbore (NWB) region.NWB damage as a result of conventional perforating. This paper presents a coiled tubing (CT) fracturing solution designed to eliminate these issues, while also delivering a new level of treatment flexibility by using real-time control of rate and proppant concentration at the perforations. This new approach to hydraulic fracturing reduces hydraulic horsepower requirements and reduces overall water usage significantly, while maximizing the return on investment (ROI) for the operator.

In low-permeability formations, natural fractures, fissures, and other geologic heterogeneities are important considerations in the design of hydraulic-fracture treatments. In some formations, it is considered beneficial to capitalize on these conduits to establish a greater network of connection to the reservoir. In the Bakken shale, near Westby, Montana, a simple planar fracture was desired because complex fracture growth could result in connectivity to a zone of nonproductive interest and led to the following issues:• Higher rates, which could result in extreme fracture complexity and limited fracture extension.• Inability to effectively place proppant for conductivity.• Excessive fluid leakoff caused by high net pressures requiring large pad volumes.• Connection to water-producing zone.• Less aggressive proppant schedule because of likelihood of screenout.• Increased cost, footprint, personnel, and equipment on location.With an understanding of the formation-rock properties, stresses, and the natural fracture system, the treatment design parameters were established to help ensure lower treatment pressures and optimum fracture extension in the zone of interest. This paper presents the successful execution of a multi-interval fracture-stimulation treatment for a long-lateral horizontal completion in the Bakken shale using a state-of-the-art hybrid coiled-tubing (CT) system and hydrajet-assisted fracturing (HJAF) technology. The new approach incorporated the following technology:• Low-rate treatment schedule.• Multiple-fracture stimulation treatment.• Aggressive proppant-treatment schedule.• Higher gel viscosity to encourage desired fracture growth and proppant transport.• Hydrajet perforating.• Dynamic fluid diversion to isolate treatment to intended zone.• State-of-the-art hybrid CT system.