The most efficient way of production enhancement is the hydraulic fracturing which has proven efficient in majority of the fields in Western Siberia and over the world. Despite wide stimulation experience in the Siberian region there are still some unresolved issues. One is the proppant flowback, a root cause of well equipment damage and also reduction in conductivity of the fracture itself. One of the ways to prevent the problem is the usage of resin-coated proppant (RCP). However there is a disadvantage of this method - agglomeration of polymeric material reduces fracture conductivity in the near-wellbore area. Since 2013 a pilot campaign with the usage of rod-shaped proppant has started in a region. This unique product has two main advantages over a classical spherical proppant: enhanced conductivity of a proppant pack and inherited proppant flow back prevention. Due to the rod-shaped form of the particles, pack has improved stability. Comparison of conductivity tests for different proppants shows that rod-shaped proppant outperforms conventional ones typically used in the region. This also leads to better fluid and polymer recovery and results in increased effective fracture length, hence in substantial production enhancement. There are 9 oil fields near Langepas a city in Khanty-Mansiysk district. These oil fields are at the latest stage of development: decreasing production rates and recovery of the most part of resources. Drilling has shifted to edge zones of the reservoirs and wells start-up is challenging due to low production rates (small net pays and low values of permeability and porosity). At the moment rod-shaped proppant has been successfully implemented in 4 wells on Jurassic and Achimov formation and the first positive results have been obtained - no proppant flow-backs detected and wells productivity enhanced by 20%. Detailed results of the first project with rod-shaped proppant application in Western Siberia (Russia), including a comprehensive analysis of well production performance, are covered in this paper.

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.

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.

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