Oil fields in Western Siberia, Russia are well-known for their diversity in size, formations, permeability and accessibility. Target of our research will be the set of oil fields around city of Kogalym. Paper will describe in details trial campaign with innovative stimulation technique and it's positive effect on operational reliability and wells productivity.
Main challenges of the Jurassic formations are low permeability and high heterogeneity. Hydraulic fracturing is required for economic wells exploitation. Historically, hydraulic fracturing in Kogalym oil fields 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 important in low-permeability formations. Another important advantage of the new technique is minimized risk of screenouts.
First step in implementing channel fracturing to Kogalym fields was made in 7 newly drilled wells showing productivity increase of up to 30% when compared to conventional fracturing. Best production results were obtained from Jurassic formations of Vatieganskoe and Tavlinsko-Russkinskoe oil fields.
The paper contains detailed description of channel fracturing technique implementation to upper Jurassic formations of several oil fields. Comprehensive analysis of pilot campaign and wells productivity together with lessons learned description allow extending channel fracturing implementation to other oil fields with similar geological challenges.