Improving Development Efficiency of Hard-to-Recover Reserves of Tyumen Formation (JK2-9) at Krasnoleninsky Field

Abstract

Summary The challenges of developing the Tyumen Formation reserves are associated with the following features: thick oil column, high heterogeneity, abnormally low permeability, and a low degree of knowledge. Historically, the development of the Tyumen Formation has been uneconomic due to low startup oil rates and high decline rates. The first active phase of development began in 2009, due to recompletions at the Talinsky license block and drilling of directional wells with hydraulic fracturing at the Em-Yegovsky license block. Those measures resulted in recoveries of less than 2% of the initial recoverable reserves. The next stage started in 2013–2015, when a pilot project of “horizontal wells with hydraulic fracturing” was successfully implemented at the Em-Egovsky license block. Together with the tax incentives to the MET rate, this made it possible to significantly expand the zones of economic drilling and ensure an increase in oil production. Based on successful practices at the Em-Egovsky license block, since 2017, the HzW + MSHF technology has been replicated at the Kamenny and Talinsky license blocks. In the next 20 years, it is planned to drill about 5,000 wells in the Tyumen Formation which will increase production by more than five times. In 2020, a pilot project was implemented to increase the length of a horizontal well (up to 1,200 m) and the number of hydraulic fracturing stages (up to 12). Note that the current tax incentives will not allow the full involvement of the Tyumen Formation reserves into development - when moving into zones of poorer quality, the development economics decreases. By the time the tax benefit expires (2030–2035), 40% of planned wells will be drilled, the recoveries from initial recoverable reserves will not exceed 20%. Further growth and maintenance of oil production will require additional tax incentives.