* Hydraulic fracturing (fracking) is a means of intensifying oil production, through the high-pressure injection of a mixture of fluids and a special proppant agent (proppant) into strata. The process of injecting the mixture creates highly conductive channels (“hydraulic fractures”) connecting the well (bore hole) and the strata. These fractures allow oil to flow that would not, under other circumstances, reach the well. Under multistage fracking, multiple fracking operations can be undertaken from a single horizontal well, allowing a manifold increase in the catchment area covered from that well.
** The key feature of this new technology, predominantly, lies in isolating the frac ports (the points inside the well from which fracking is expected be undertaken) from each other. Under more traditional “ball and socket” technology, each new fracking zone is separated from the preceding one by a metal (or composite) ball. The diameter of these balls increases from zone to zone, with the result that the way these wells are constructed makes more than 10 fracking operations impossible. Multistage fracking at the Yuzhno-Priobskoye field did not involve using balls as isolators, but, rather, a special instrument with a multiuse compacted “cushion”, which expands to isolate those areas in which fracking has been completed. Once work has been completed this deflates to its normal size and can be transported to the next area of the well from which fracking is to take place — in contrast to the more traditional balls, which have to be destroyed once fracking is completed. In which circumstances, the number of fracking operations is limited only by the extent of the well itself, and by technical and economic considerations. In addition to which, this method allows research to be undertaken from within the well, as well as allowing repeated fracking and the quick commencement of production once all fracking operations have been completed.
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