Unconventional reservoirs require innovative completion techniques and technology to become more economical. Formations vary drastically in lithology, lateral lengths, completion methods, and financial drivers. Since reservoir conditions typically mandate the use of hydraulic fracturing for economical production results, a significant amount of resources are focused on making the fracturing process more efficient and lowering its environmental impact. This case history includes an operational review focused on a novel technique to rapidly perform targeted annular hydraulic fractures by deploying an activation tool on coiled tubing (CT) to open frac sleeves in a horizontal well. The paper covers results and information gathered from the first operation of its kind in Montana's Bakken Formation – where a total of 19 stages were fractured in the shaley dolomite. The new technology does not involve dropping balls or setting composite plugs to isolate stages. Rather, the technique utilizes frac sleeves that are activated using a CT bottomhole assembly to save time between stages. The sleeves can be cemented in place if desired and have a full-bore internal diameter that does not require post-treatment composite plug millouts, further reducing overall completion time and time to production. Additional capabilities of the system enable the use of memory gauges to monitor downhole pressure and temperature characteristics. The operator preferred this method due to its targeted nature, efficiency, and fluid savings. As opposed to multicluster fracturing methods (such as ‘plug-n-perf"), a single entry point during the frac job promotes increased fluid velocity, enabling a more aggressive sand ramp and reduction in required hydraulic horsepower. Similarly, the single entry point ensures that a fracture is generated at each port, as opposed to the possibility that some clusters are not treated. In addition, no composite plugs or diverting devices are required to be pumped down the wellbore, so water usage is reduced considerably. The system, already used in thousands of fracturing stages in Canada, speeds up the completion process, uses less fluid, minimizes risks, and reduces overall downtime.

The struggle to define an optimized completion strategy remains a significant challenge in unconventional multistage horizontal wells. Stage and cluster spacing is a design decision that often requires significant experimentation to determine what is the optimized spacing of propped fractures that efficiently drains the reservoir yet can be reliably pumped to completion. This paper illustrates the importance of bottomhole (BH) gauge data for evaluation of stage and cluster spacing and general completion quality. The knowledge derived through careful analysis of this valuable data source, can significantly reduce the amount of experimentation typically required in other completion techniques. Consequently optimized field scale completion strategies can be refined with efficiency and reduced overall costs.Coiled tubing (CT) assisted hydraulic fracturing (HF) is a good alternative to the standard plug and perf completion in multistage horizontal well stimulation. During a CT HF operation, fracturing is initiated via pre-installed frac sleeves or sand-jetted perforations. One of the advantages of CT fracturing is improved target fracturing, where a single-entry fracture initiation point can be placed at the desired depth to target the best rock for stimulation. Another benefit of CT fracturing is the ability to gather BH treating pressure via BH gauges (BHG) mounted on the CT bottomhole assembly (BHA). Bottomhole pressure and temperature gauges, installed above and below the isolation packer, provide valuable information about fracture communication between stages, cement integrity and stress shadowing. This paper will review dozens of CT frac jobs performed across various basins in North America. Information obtained from BHG is merged with surface treating pressure and other diagnostic data sources and subsequently analyzed. One key area of analysis is to examine stage communication data for stress shadowing effects. The primary takeaways from this paper are to illustrate the importance of BHG data, how it compares to other diagnostic data, and how it can be analyzed to effectively drive the stimulation design process.