Unconventional Approach for Fracturing Stimulation in Conventional Low-Permeability Formation by the Example of Experimental Part South Priobskoe Field
Authors: Kazakov Evgeny , Fayzullin Ildar , Sheremeev Aleksandr , Shurunov Andrey , Chebykin Nikolay , Uchuev Ruslan , Serdyuk Andrey , Vikhman Ivan , Prunov Dmitry 
Published: October 2019

The main challenges in the development of terrigenous reservoirs of the Yuzhno-Priobskoye field include the search and implementation of technological approaches and solutions that allow the most effective stimulation of reservoirs in conditions of low permeability. The complicating factor for such objects is the low influence of flooding and, as a consequence, insufficient compensation of reservoir pressure. These restrictions lead to a high decline rates in oil production. So the most pressing issue is the search for an actual technological solution aimed at improving the efficiency of field development.

The article describes the results of optimizing the completion system and the search for an effective integrated solution to stimulate the low-permeability reservoir in pilot area on the Yuzhno-Priobskoye field.

The choice of development plan (the optimal location of the horizontal wellbore and hydraulic fracturing sleeve) based on the results of geological and hydrodynamic modeling. Drilling of the horizontal section was made in the direction of the minimum horizontal stress for creation the transverse hydraulic fracks. The main purposes of the project were - realization of pilot on Priobskoye field with the different completion technologies, variations in fracture designs and the number of stages, as well as the evaluation of the effectiveness of these approaches to the dynamics of wells.

The main solutions to optimize the design of completion and stimulation of wells in the conditions of the object include: High consumption of combined fracturing in a cemented liner using working low-viscosity liquids at buffer and proppant stages"Plug&Perf" technology for MSHF in a cemented liner as an alternative to the classical arrangement with sliding ball sleeve.

The criteria of technical success of hydraulic fracturing operations are identified on the basis of the applied technological solutions. Technology boundary criteria specified on concentration and type of the used fractions of the proppant in low viscosity of the fracturing fluid, and the ratio used in the crosslinked and linear fluids.

Recommendations on the choice of the optimal perforation interval, the density of perforations and the type of charges used are formed for the "Plug&Perf" technology. Conclusions are made on the applicability of this method of completion, as well as its optimization under the current conditions.

The comparison between the stimulated wells and other wells in the pilot area is carried out The main features and directions for the optimization of further decisions in the field of fracture design are identified.

Applied technological solutions assessment shows an increase of the drainage zone and an raising in the accumulated oil production for the considered area of the Yuzhno-Priobskoye field.

The conclusions will subsequently allow to improve the completion design and stimulation of wells with hydraulic fracturing, as well as to offer solutions for other fields with similar conditions.