Precise Fracturing: Increasing Number of Stages and Reducing Treatments Size in Oil Rims of Novoportovskoe Oil Field
Today, an effective application of multistage fracturing (MSF) became an
acute problem for the Yamal Peninsula fields. At Novoportovskoe oil and gas
condensate field, in order to achieve an effective reservoir coverage with
fractures to increase hydrocarbons recovery, it was decided to revise the
concept of horizontal wells completion, increasing the number of MSF stages and
decreasing the distance between the stages.
In the complex geological conditions of the Novoportovskoye field, a
fundamentally new solution was proposed for horizontal well completion –
full bore MSF system with sliding sleeves, operated by hydraulic shifting key
with coiled tubing (CT). This completion system allows to perform MSF without
pulling CT out of the well to the surface and instantly use CT for well
cleanout in the case of screenout (SO). This decision is aimed to increase
production and achieve economic efficiency of the field development by
increasing the formation coverage by means of larger number of MSF stages per
well, and optimizing costs by reducing the time for the entire range of work at
At the moment, 2 wells at Novoportovskoe field were completed with
described MSF system, with total 40 stages fractured.
The technology allowed increasing of stages number to 20 in a 1000 m
long horizontal section and installing selectively ports in the most effective
zones of the formation. The coefficient of formation coverage was increased due
to uniform placement of longitudinal fractures, which could not be achieved
with standard "ball" MSF technologies.
As a result, by reducing treatment size and increasing number of stages,
positive results were achieved: the water cut was 39%, with an average of 60%
and the gas factor was 472 m3/t, with an average of 800-1000
m3/t in neighboring wells.
As a result, with use of integrated completion system with shifting
ports, fracture control was obtained in real time due to coiled tubing
functioning as a dead string during fracture, and, at the same time, data was
stored at memory downhole gauges installed in the CT bottomhole assembly
Innovative technology and a comprehensive approach to the design and
implementation of fracturing operations in complex geological conditions of the
Novoportovskoe field is a unique experience for the region. The possibility to
increase an oil production of a horizontal well MSF (HWMSF) without breaking
fractures into the gas cap was proved. This system has advantages with respect
to standard MSF technologies in conditions of oil rim deposits, and is
applicable for other projects where an increase of MSF stages and the
completion cycle time reduction is required.