Gazpromneft Khantos (a subsidiary of Gazprom Neft) has completed 18-stage fracking* at the Yuzhno-Priobskoye field, Khanty-Mansiysk Autonomous Okrug. This is the first time such an operation has been undertaken within the Gazprom Neft Group — the maximum multi-stage fracking operation through a single bore hole in a horizontal well, thus far, having been undertaken at the same location, the Gazpromneft Khantos Yuzhno-Priobskoye field, in December 2015. Increasing the number of fracks per well has been made possible through the use of non-ball-and-socket (Mongoose) well completion and stimulation technology**.

With a well-depth of approximately four kilometres, and the horizontal section running to 920 metres, anticipated operational potential is at least 80 tonnes of oil per day, 15 percent higher than performance levels following lower-stage fracking operations. The key feature of the configuration of the horizontal section of the well lies in its allowing well stimulation to continue throughout its entire operation. The application of multi-stage fracking not only allows an increase in the well-flow rate (production rate) but also, in the long term, allows a greater proportion of hard-to-recover reserves to be developed, by identifying the optimum means of developing the more marginal blocks of a field.

Gazpromneft Khantos brought 373 wells into operation in 2015, 52 of which were horizontal wells using multi-stage fracking.

Vadim Yakovlev, First Deputy CEO, Gazprom Neft, commented: “Gazprom Neft’s official Technology Strategy is designed to support the constant search for innovative solutions around which its long-term development might be based. Work with hard-to-recover reserves allows the company to further improve technologies designed to improve oil recovery, and bring into development reserves previously deemed unviable.”

* 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.