Hybrid fracking involves using process fluids, with various properties and characteristics, in combination. The advantage over standard fracking here lies in its more extensive coverage, due to longer fissures being created, and the more extensive network of micro-fissures created around these. This effect is achieved by adjusting injection fluid and proppant volumes and formulations, and increasing the speed at which these are injected.
An 8-stage fracking operation was undertaken at the Vyngayakhinskoye field, during which a new fracking fluid was tested, significantly increasing fracking efficiency. The outcomes of this work indicate an initial production rate three times higher than anticipated.
The objective in testing is to verify the hypothesis regarding in-strata fissure-network formation, and to test the technology’s efficiency. In the course of desk research specialists from Gazpromneft-GEO, the Gazprom Neft Science and Technology Centre, Gazpromneft-Noyabrskneftegaz and the MIPT Centre for Engineering and Technology developed a specially designed fracking technique which increases production under the geological conditions inherent in the Vyngayakhinskoye field.
The outcomes of this work have confirmed the technical feasibility for creating fissures up to 3 to 5 times longer than standard — i.e., of more than 500 m. These initial testing outcomes could, according to specialists, significantly change accepted opinions on optimum criteria for developing Achimovsky strata, and will facilitate a major step forward in reducing capital costs per tonne of oil.
«The resources held in Achimovsky strata in the Noyabrsk area alone stand at more than 1 billion tonnes of oil. These are huge reserves, production of which under currently available methods is limited by the complex geological structure of these strata. Reservoir permeability at the Vyngayakhinskoye field is somewhat low, even for traditionally low Achimovsky deposits, at 0.4 millidarcies (0.4 mD). We expect new technologies, some of which are, already, undergoing successful testing at the company’s fields, to open up access to Achimovsky-strata oil», said Yuri Masalkin Director for Geological Prospecting and Resource Base Development, Gazprom Neft