Challenges and Uniqueness of a Dual-Injection Fracture Model

Approximately 23% of US land operators have tried simultaneous pumping operations and reported on average more than 30% gain in efficiency. However, surface efficiency without comparable well performance is not useful—all simultaneous fracturing jobs demand compromise in completion strategy or pumping schedule. The simultaneous fracturing model has been developed as an enhancement to the existing complex fracture model describing propagation of a hydraulic fracture in conventional and unconventional formations with the capability to simulate simultaneous pumping operations. The simultaneous or timely delayed pumping could be from the same pad or even offset pads—there is no limitation. This will include proper modeling of fracture initiation, propagation, and interaction between fractures from different wells through stress shadow effects and crossing rules. The simultaneous fracturing model will allow engineers the ability to design, evaluate, and optimize the efficiency of simultaneous fracturing. The enhanced model also allows evaluation of different pumping schedules, well placement schemes, and scenarios to improve cluster efficiency. It will help to achieve the next level of surface efficiency through predictive modeling of simultaneous fracturing from different wells on the same or different pads. The new approach is bringing new challenges to the model to account for the different previously unaccounted for field related scenarios and situations, as well as will open new modeling related issues and problems. This will be the main topic of the paper. 1. INTRODUCTION As an alternative to the widely used zipper-fracturing technique, the new completion technique of simultaneous fracturing (simul-frac) became more popular among US-shale producers (Jacobs, 2021). In simul-frac operations, one pumping crew can stimulate two horizontal wells at the same time and reduce completion times by more than half compared to the zipper-fracturing approach (Fig. 1). Some examples of successful simul-frac stimulations can be found in the papers by the Matador Completions Team (2023) and Chevron (Kim et al. 2021). The typical simul-frac operation requires at least 25% more horsepower than the average zipper-frac spread. Simul-fracs require splitting the pumping rates between two wells, and while more pressure pumping units, i.e., an additional four stimulation pumps are required to be on location, they function at lower rates and spend less time on each pad - enhancing pumping efficiency and maximizing resource usage by significantly trimming pad completion time. The interaction between fractures during simultaneous fracturing is, in a way, similar to the parent-child interaction, with the difference that the interaction is in real-time mode, when both jobs are still active, and both networks are still propagating.