Case Studies of Re-Fracturing Achimov Reservoirs with High-Viscous Friction Reducer on Salym Group of Oilfields

Abstract

One of the main objectives for the successful development of the majority of producing oil and gas companies in western Siberia is the development of the Achimov strata. It contains a commercially attractive volume of reserves. This reservoir in most oilfields belongs to the hard-to-recover oil - it has a permeability of less than 2 mD. In this regard, the development of the Achimov strata is impossible without carrying out measures for production enhancement. Where most common is hydraulic fracturing. The wells tests with hydraulic fracturing conducted at the Salym group of fields showed that not all reserves are economically attractive, and the decline rate in the first year is extremely high. In this connection, the needs of finding more effective solutions for the production enhancement has become urgent. This article describes the results of pilot work on two wells using a mixture based on a high-viscosity friction reducer (HVFR) as the hydraulic fracturing fluid. The work was carried out at wells where hydraulic fracturing based on cross-linked gel had already been performed and the wells were launched into production. The results of the work, the lessons learned and the analysis of the subsequent production of these wells is the purpose of this work.