A REVIEW OF CURRENT WELL PACKER DESIGNS AND A CRITICAL ANALYSIS OF THEM

Abstract

Well packers are a vital part of oil and gas well equipment, ensuring hermetic separation of the wellbore into intervals and isolating productive zones during production, hydraulic fracturing, acid and thermal treatment of the near-wellbore zone, injection of working fluids and testing of blowout prevention equipment. This paper categorises modern well packer designs and critically analyses their pros and cons, based on a comparative study of technical documentation from major manufacturers such as Halliburton, SLB/Schlumberger and TAM International, and scientific publications by domestic and foreign authors. It also presents a synthesis of the results of numerical modelling of the stress-strain state of sealing assemblies using the finite element method. The paper classifies packers according to their actuation method (mechanical, hydraulic, self-sealing, sleeve-type, inflatable or swelling) and whether they are retrievable or permanent. The sealing capacity of any type of packer has been found to depend on the design of the sealing assembly and the properties of the sealing element material (NBR, HNBR, FKM, AFLAS/FFKM and swellable elastomers). The selection of these materials represents a compromise between cost, thermal and chemical resistance, and extrusion resistance. The main shortcomings of existing designs have been identified, including elastomer extrusion into the radial gap, non-uniform contact pressure distribution along the sealing element, stress relaxation, and rubber chemical ageing over time. The service life of swelling packers ranges from several days to weeks, and they are sensitive to temperature and fluid composition.  Information on various types of packers, from an industrial and scientific perspective, has been systematised and organised into a single classification scheme. This scheme provides a quantitative comparison of operational parameters and identifies gaps in existing research. These gaps include the lack of a systematic methodology for designing sealing assemblies, insufficient study of the behaviour of new materials during long-term operation and the need to optimise anti-extrusion elements for high-pressure and high-temperature conditions. This information can be utilised when designing new well packer configurations and outlines promising directions for further research.