One of the priority directions of technological development of RUE "Production Association" Belorusneft "is the involvement in the development of unconventional oil reserves and enhanced oil recovery.
Achievement of this goal was hampered by such a technological challenge in the field of well construction, as providing reliable support for a well with an extended horizontal completion during development by the P&P method.
The essence of the challenge was that when performing a cluster or multi-stage hydraulic fracturing, increased loads are created on the well support, which can violate its isolation.
The complexity of the geological and technical conditions in the Pripyat trough lies in the large length of horizontal ends in salinized carbonate reservoirs and high hydraulic fracturing pressures during well development.
The article discusses solutions for the design and creation of a reliable cement sheath for the given geological and technical conditions.
To overcome the technological challenge, a cementing technology was developed, including a plugging slurry formulation with elastic properties of a cement stone and a casing rotation technology during the cementing process.
The plugging slurry formulation was developed with the elastic properties of a cement stone with cement mixing in salt water, adapted to the conditions of the salinized rocks of the Pripyat trough. To develop the formulation, the simulation of the pressure effect during the development by the P&P method on the cement stone behind the casing was used, as well as the simulation of the process of displacement of the drilling mud by the plugging slurry.
The technology was successfully tested at five sites when horizontal wellbores were fastened with 114 mm tie-back casings, while high cementing quality indicators were achieved. The lengths of the tie-back casings ranged from 509 to 1000 m.
The article presents the results of assessing the quality of cementing using acoustic cementometry and assessing the density of the medium behind the casing by gamma-gamma cementometry, as well as comparing the quality of cementing with casing rotation and without rotation, before and after the impact of P&P development.
In RUE "Production Association" Belorusneft "it was decided to use the developed technology in default for attaching 114 mm liners with subsequent development using the P&P method.
