Abstract

Paper describes in details a trial campaign with channel fracturing technique and it's positive effect on operational reliability and wells productivity that helped to revitalize brown Urevskoe oil field.

Main challenges of the Jurassic formation are low permeability and high heterogeneity. Hydraulic fracturing is required for economic wells exploitation. Historically, hydraulic fracturing in oil fields close to the city of Langepas was developing towards aggressive designs with cleaner fractures, although increased risk of premature screenouts is encountered with such approach. To further improve efficiency and economics of stimulation treatments, a logical step in conductivity enhancement was made implementing channel fracturing technique. Channel fracturing allows for heterogeneous proppant placement leaving open channels inside proppant pack. Thus, conductivity of the system increases significantly. Channels also help to better clean out fracture from fluids and polymers increasing an effective fracture half-length, which is a goal in low-permeability formations. Another important advantage of the new technique is minimized risk of screenouts.

Campaign was made implementing the technique to re-stimulate wells in brown Urevskoe oil field in Langepas area. Open channels showed reliable production increase from old wells in depleted regions. Proppant flowback is a common problem in such conditions and was encountered in many offset wells, therefore channel fracturing was enhanced by rod-shaped proppant at the tail-in stage. Such combination allowed preventing proppant flowback issues and improved conductivity in near-wellbore zone.

Worldwide, this trial campaign is one of the pioneering re-stimulation projects implementing channel fracturing. Comprehensive analysis of performed operation, production comparative results and lessons learnt will make it possible to successfully extend the use of innovative technologies to many other brown fields that require stimulation.

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