Overcoming Challenges in Fracture Stimulation through Advanced Fracture Diagnostics

Abstract

Historically, different fracture diagnostic methods have been used for hydraulic fracturing treatments to obtain estimates of reservoir characteristics, fracture design parameters, and treatment progress. However, the advent of horizontal drilling techniques and expanded interest in unconventional reservoirs has increased the challenges to overcome to achieve a successful hydraulic fracturing treatment. This paper details advancement made to conventional methods of fracture diagnostics to meet these emerging challenges. A comprehensive study was conducted on the latest advancements in different diagnostic techniques. Several published case histories were studied where these techniques were adapted and modified from their conventional form. The effectiveness of the advanced techniques in terms of providing additional information was analyzed. A comparative review of the diagnostic methods was performed to determine individual limitations and to identify fit-for-application scenarios. An attempt was made to classify and categorize them according to the ease of application and usefulness for treatment design and analysis. This study suggests that proper planning, deployment, execution, and analysis of the techniques are essential to helping prevent erroneous conclusions about the treatment and job design. When conducted in unconventional reservoirs, conventional pressure diagnostic methods, as a result of the underlying assumptions of rock properties and fracture geometry, can be interpreted inaccurately. Use of high-fidelity forward models for the inversion of data acquired through these methods can lead to better understanding and help mitigate incorrect interpretation of the results. Similarly, fracture injection-falloff analysis combined with microseismic monitoring and distributed temperature and acoustic (DTS/DAS) data can provide deeper insight into the treatment, particularly for horizontal wells with simultaneously propagating multiple transverse fractures. Thus, a synergistic combination of different diagnostic techniques leads to more effective treatment designs and should be preferred if economically justified. The current work provides information on advanced fracture diagnostic methods and is useful for determining suitable diagnostic techniques for designing hydraulic fracture treatments.