Abstract
In the petroleum industry, packers refer to the components/products which are used to isolate one section in a formation from others, or to isolate the outer section of a production tubing from the inner section, which may be a casing or a liner or the wellbore itself. Mechanical packers are installed through some form of tubing movement. Permanent packers are low in cost and provide better seal. Retrievable packers have lower sealing capability but are re-usable after repair, and therefore expensive. More innovative packers made of swellable elastomers are rather new. These elastomers swell when they come in contact with different types of fluids (mostly water and oil). Like a casing, these new packers are lowered to the desired depth and allowed to swell before production or injection operations begin. Various studies have been published about the swelling and mechanical response of these elastomers. However, many questions remain about the sealing performance of swell packers, and their effectiveness in actual wellbores of rough and random profiles. This paper describes the design and development of an experimental unit for performance testing of a mix of inert and swelling elastomer seals under realistic well conditions. Actual swell packers and petroleum tubulars are housed in a concrete block that replicates open-hole and cased-hole wells through layers of varying roughness. This is a one-of-its-kind unit providing full-scale demonstration about the working of swell packers against outer casing or rock formation in a wellbore. It is also a complete testing apparatus to investigate the behavior of swell packers made of fast-swell and medium-swell elastomers, and how they seal off irregular boreholes. This work can provide basic understanding and visual corroboration to petroleum engineers and students, swelling elastomer application developers, and academic and research personnel.
Highlights
Packers are used in petroleum drilling and development to isolate one section in a formation from others, or to isolate the outer section of a production tubing from the inner section, which may be a casing or a liner or the wellbore itself (Glossary 2019)
The inner-most pipe is a swell packer comprising of inert and swelling elastomer segments sealing against a casing pipe. Another set of swelling elastomers is mounted on the outside of this tubular, and swells to seal against the formation, in the form of a concrete block with layers of varying roughness as would be the case in a real formation (Qamar et al 2012b; Pervez and Qamar 2011). This is the only setup of its kind, with several key objectives: Life-size demonstration of how a swell packer seals against an outer steel casing or against the rock formation in a wellbore; investigation of the swelling response of a rapidswell (E1) and a medium-swell elastomer (E2) in shallow aquifer type wells; and experimentation and visual display of how the swelling elastomer segments provide sealing against uneven formations and irregular surfaces
For operating conditions in shallow aquifer type wells (50 °C temperature and 1⁄2% salinity), it was expected that the elastomer would swell by about 70% in the outer packer in six hours, based on swelling tests conducted on laboratory-size samples (Patel et al 2019; Qamar et al 2009, 2016; Pervez et al 2012), confirming its fast-swell character
Summary
Packers are used in petroleum drilling and development to isolate one section in a formation from others, or to isolate the outer section of a production tubing from the inner section, which may be a casing or a liner or the wellbore itself (Glossary 2019). Keywords Testing-demonstration unit · Design and construction · Swell packer · Swelling elastomer · Water-swell · Oilswell · Open-hole · Cased-hole · Formation roughness
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Petroleum Exploration and Production Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
