The channel fracturing technique achieves heterogeneous proppant placement by pumping pulses of proppant laden slurry and clean fluid in alternating sequence. Successful creation of proppant banks in the fracture provides stable channels of infinite conductivity which reduces pressure drop across the hydraulic fracture and enhances production. To date, more than 15,000 fracturing jobs have been successfully placed in various types of formation and completions using the heterogeneous proppant placement technique.

The mechanics of delivering the treatment involves pumping pulses of alternating clean and dirty pulses of fluid with fibers that keeps the proppant in suspension. This is then followed by a continuous proppant "tail-in" stage towards the end of the job before the flush stage. This tail-in ensures continuous proppant bank at the near wellbore region to ascertain good connectivity between wellbore and the channel spaces created during the treatment.

To understand importance and requirement of tail-in, simulations and field execution of jobs with or without tail-in in channel fracturing treatment have been done. Furthermore, a bigger sized unconventional rod-shaped proppants have been also used towards end of the channel fracturing treatments. The unconventional proppants not only helped on such treatments to minimize pressure drop across the tail-in but also helped to reduce proppant flowback in softer formations.

The impact of tail-in on pressure drop and production rates in different formations have been consolidated in this study which provides proppant selection criteria for channel fracturing tail-in stage. Simulation results in shale and sandstone reservoirs and the field treatment case histories comparing the production results for wells completed with and without tail-in in channel fracturing treatment are presented.

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