An invention for boosting oil production by optimizing the well start-up process after hydraulic fracturing patented by researchers from Skoltech and Gazprom Neft STC has been named winner of the Successful Patent contest in the Big Business category. A total of 129 Russian patent holders from 21 regions took part in the contest. The winners in other categories include the Gamaleya National Center of Epidemiology and Microbiology (NICEM) with its Sputnik-V vaccine for COVID-19, an inventor of simulators for the rehabilitation of patients with cerebral palsy, and a train-interval control system for the Russian Railways.
Hydraulic fracturing, one of the key methods to increase hydrocarbon production, is commonly used as part of the well stimulation process on the majority of newly drilled wells. It involves creating multiple cracks in an oil or gas formation by injecting a fluid containing proppants (ceramic granules) to form a highly conductive porous channel from the formation’s deep layers towards the well in order to increase the flow of gas, oil, gas condensate or their mixture into the well bottom-hole.
Aggressive cleaning that follows hydraulic fracturing may wash out or crumble the proppants and, therefore, decrease the crack’s half-length and affect the crack’s conductivity and further production. None of the existing approaches provide a quantitative assessment of these effects or an optimal well start-up method to maximize well productivity and ensure long-term crack conductivity.
“The idea to model the crack clean-up process was first proposed by Skoltech professor Andrei Osiptsov around 2017. Grigory Paderin and I tried to figure out why, according to hydrodynamic research and field data, hydraulic fractures produce less oil than they should have according to the specifications,” Yegor Shel of Gazprom Neft STC recalls. “After a long inquiry we concluded (and so did our colleagues at Skoltech) that there is something wrong with the crack clean-up process which follows hydraulic fracturing and which no one had previously tried to model, control, or even quantify. We have been focusing on this task since 2018. In 2019, our team collected field data and in 2020, performed experiments in the lab. Simultaneously, we worked on a physical and mathematical model of the process. In 2021, we finally came up with a concept of a controllable well start-up after hydraulic fracturing which helps deal with the insufficient crack clean-up issue and increase production.”
“It was true teamwork with a strong synergy between Skoltech researchers and our partners at Gazprom Neft STC,” professor Andrei Osiptsov, director of the Skoltech Project Center for Energy Transition and ESG, says. “Skoltech’s team included Sergei Boronin who developed a hydrodynamic model for well-fracture-reservoir clean-up and Albert Vainshtein who coordinated the oil well pilot operation in the Priobskoye field in collaboration with the Gazpromneft-Khantos subsidiary and interpreted the results. This ambitious project that has come a long way from the optimal well start-up concept and the coupled fluid mechanics/geomechanics modeling to the field testing and interpretation of the data, would not have been possible without the all-round support from our partners at Gazprom Neft STC. We give our special thanks to Grigory Paderin and Yegor Shel for contributing to the research efforts and organizing the well pilot operation through a Gazprom Neft subsidiary.”
In March 2021, following a series of publications in industry journals, such as JPSE, the team took out FSIS (Rospatent) Patent for an Invention N 2745684 which has won the award at Successful Patent this year.
The authors thank their colleagues from the Gazprom Neft STC Intellectual Property Department and, in particular, Natalya Denisenko, for their help in applying for a patent and the contest.