South-Priobskoe field is in process of active development for over 10 years at the moment. Main producing horizons are low-permeable sandstone formations AS10-AS12 of Neocomian age. Hydraulic fracturing in the vertical wells proved to be effective way to increase oil production and provided profitable development of the oil field for several years period. Many wells had commingled production from 2 or 3 layers; each of the layers was stimulated separately. However, recent shift of drilling and development activity towards edge areas of the field led to reduction in formation quality and seldom well intersects more than one productive interval nowadays.
Most effective way for such geological conditions is combination of horizontal well drilling development and multi-stage fracturing. This concept was successful applied worldwide for number of years and recently fulfill expectation at South Priobskoe field in Russia as well. Enhancement of oil production jointly with drainage scheme optimization allowed to decrease amount of wells and associated costs for infrastructure and well completion. Main weaknesses of this approach are increased screenout risks during fracturing operation and additional costs for horizontal wellbore cleanout in such a case.
Implementation of channel fracturing technology became the next step of production optimization and well completion cost reduction. New method allows increasing reliability of proppant placement while improving fracture conductivity. These results are obtained by pulsing proppant on surface in conjunction with specialized equipment and fibers. New technology was implemented in 110 vertical wells over Russia including positive experience of channel fracturing campaign in 3 wells in South-Priobskoe field.
This article describes Russia's first project of multistage stimulation (MSS) combined with channel fracturing technique applied in horizontal well. New approach allowed minimizing screenout risk, reducing completions costs and at the same time improving conductivity of hydraulic fractures. First production results showed increase in well productivity of over 15% compared to the neighboring horizontal wells stimulated by conventional MSS technique.