Fiber optic technologies (DTS/DAS) and production logging measurements in North America have repeatedly demonstrated that limited entry conditions (i.e., back-pressure) only persist for a few minutes after proppant reaches the primary casing exit points. This identification of a real and material problem with respect to fluid exit efficiency indicates that limited-entry alone is not sufficient, and some enhanced strategy must be deployed. Diversion technology has been introduced to provide improvements to this result. This presentation will describe the current state of diversion technology being used in new wells to impact the fracture initiation point count spacing and cluster flow efficiency.
Recent advances in fiber optic technology utilized both during the stimulation process and during production afterward have demonstrated that flow is actually 4-dimensional in nature and dynamic over time. During pumping operations, there can be chaotic arrangements of casing exit points which allow flow (breakdown) and no flow, as well as wild temporal fluctuations in cluster-specific flow rates. Adding diversion strategies to this already dynamic environment has further escalated the complexities observed, while revealing the necessity to define the fundamental system influencing variables that affect the success of the diversion outcomes.
Measuring completion parameter sensitivities with standard diversion practices is much less reliable as compared with integrating a systematic engineered approach that addresses the root causes of the high-variability. New methods being investigated are seeking to tighten the window of uncertainty associated with chemical diversion, thus enabling a greater understanding of the diversion process, and facilitating more effective calibration of pumping and completion designs based on diagnostic measurements.