A World-First For Rawwater:
The 3,000-Year-Life Underwater Cast Metal Seal
We are looking forward to showcasing our development of novel alloys for oil well plugging and abandonment at the 9th SPE Well Abandonment Symposium – 26th and 27th June 2019, Aberdeen Exhibition and Conference Centre.
Recognising the need for a specialist alternative oil well plugging medium to cement, we have recently created the world’s first ‘anticipated’ 3,000-year-life underwater cast metal seal. The metallurgy has been certified by Bureau Veritas as fit-for-purpose for extreme life applications in the oil and gas industry and qualified to the V0 (highest rating) of ISO 14310.
At the 9th SPE Well Abandonment Symposium, we will be presenting research which underpins our belief that the development of bismuth alloys provides the opportunity for a significant reassessment of current approaches to well abandonment in particularly challenging applications, including resealing failed abandonments that were previously plugged with cement. Our strength lies in knowing the specific circumstances where such alloys can be used, as well as where they cannot. As such, we look forward to demonstrating how, through the use of the correct types of bismuth alloy, operators can benefit from long-term plug integrity, longer plug life and significantly reduced deployment costs.
A pedigree of expertise
We have been investigating the use of bismuth alloys as a plugging medium for almost twenty years and, over that time, have built a large corrosion and creep database regarding the use of underwater cast bismuth alloys. We invented the Bismuth Plug and have completed in excess of 100 workshop trials using novel alloys specifically formulated for plugging and abandonment – recording a zero failure rate throughout the programme. Rejecting common bismuth alloys, we have produced a suite of proprietary expanding metal alloys for use as high integrity seals in oil well abandonment. The alloy properties of low melting point and expansion upon solidification enable high integrity seals to be cast in-situ, without the inherent creep issues typical of bismuth tin.
7” alloy plugs rated to 6000psi
To achieve offshore capability and extreme reliability, we recently completed a two-year programme to deliver 7” alloy plugs for deployment in the North Sea, rated to 6000psi differential pressure at 60cm (2’) in length. Extensive development and testing was conducted in collaboration with an operator consortium and the UK Government to develop the formulation of the metal seals. To establish the mechanical properties and creep behaviour of the alloy under service pressure and temperature conditions, we partnered with the University of Aberdeen, through an Oil & Gas Innovation Centre (OGIC)-funded partnership.
Strict technical qualification programme
The result of our research is a suite of alloys for onshore, offshore and subsea plugging and abandonment, with operating envelopes to cover downhole geothermal temperature conditions from 158 -194°F (70 – 90°C) and 284 – 320°F (140 – 160 °C). These alloys have been subjected to a strict technical qualification programme overseen by Bureau Veritas, with stringent adherence to the qualification processes stipulated by DNV-RP-203 – Jul 2013, ISO 14310 (V0) and Oil & Gas UK. They are intended as a cost-effective alternative for sealing well abandonments and resealing failed abandonments that were previously plugged using cement. The application includes both casing plugs and plugs/seals in undefined and/or rough walled geometries (e.g. cap rock) that are difficult to seal with existing technologies such as cement.