Melted metal technology sees 300-hole implementations

In a molten state, a metal alloy with a water-like viscosity and then in a hermetically sealed gas seal that quickly solidifies has recently achieved expansion of the pit. This is according to a new announcement from BiSN Oil Tools in the UK, which develops bismuth plugs for a variety of applications.

Founded in 2011 and backed by BP’s venture capital units, BiSN said oil and gas companies around the world are using their innovation where they would otherwise use cement or elastomers. Cases of use for land and sea wells include permanent abandonment of wells, repair of casings / pipes and closure of water or sand production areas.

BiSN’s technology is based primarily on a customizable alloy made of bismuth and tin.

The company-owned alloy is shipped in its solid state around the outside of a heating system. The heat element is made of termite, a compound of iron oxide and aluminum dust, and requires only a small explosion of energy given off by a power line to trigger a chemical reaction.

When heat rises to a predetermined melting point, a bismuth-based alloy begins to leak. BiSN said the liquid alloy will go in and around the well where the water can spill. This includes holes, screens, and rings.

BiSN calls the solidification process “almost instantaneous” because the alloy passes from a liquid to a solid as soon as its temperature drops below the melting point. During this transition, the alloy expands in the same way as water cools when ice cools.

All this takes just a few minutes, and within a few hours, the well is ready for a pressure test to see if it holds the seal.

BiSN said it controls the melting point and heat of its termite system by using damping and binding chemicals. This prevents the exothermic reaction from forming temperatures that would damage the well casing or the components of the well. The upper limit used by BiSN for its outlets is around 300 ° C (572 ° F), and the housing can begin to degrade due to excessive heat above 800 ° C (1,472 ° F).

He is preparing to spread a 50-meter-long bismuth alloy plug in the hole.

Source: BiSN.

Connecting a billion barrel area

The biggest dropout work BiSN has done so far has been the focus of a case study presented this year at the Offshore Technology Conference (OTC) in Houston. OTC 31897Authors from BiSN and AkerBP shared details on how 35 bismuth plugs were used to cover and abandon 30 wells (P&A) in southern Norway.

The P&A campaign was launched in the Valhall oil field in 1975 and has produced more than 1 billion BOE in the last 40 years. AkerBP wants to produce another billion BOEs in the field over the next 40 years. To do this, he had to cover all the original wells in order to drill new ones.

The highlight of the P&A project is the use of the largest bismuth plug ever made. According to BiSN and AkerBP, the document stated that the record-setting plug measured 50 feet long and weighed nearly 34,000 lbs, of which about 20,000 lbs were made of bismuth alloy.

During the 30-well project, BiSN and AkerBP reported that 350 tons of bismuth alloys had been sent down the hole. The technology has helped AkerBP reduce its original P&A timeline from 10 to 4 years.

Following its first P&A campaign in 2014, it used conventional stamping technology. After that first attempt to seal the wells, 14 showed no annular gas pressure. However, the situation became more worrying over time.

By 2019, the number of wells with zero pressure accumulation had been reduced by only four.

At that point, AkerBP wanted to classify BiSN technology with a 2-year trial inside a well with one of the highest levels of permanent carcass pressure.

The bottom gauges showed that the first part of the ring used for the bismuth plug had a psycho reading of 0 psycho during the 2-year follow-up effort. The ground chambers were also used and confirmed that no gas bubbles were leaking from the outlet location.

Due to its non-corrosive nature, BiSN stated that alloy plugs should last for thousands of years. This is based on the laboratory results mentioned in the technical document of the companies, which suggests that the duration of the plugs may be more than 100,000 years.

For more reading

OTC 31897 Bismuth plugs cover all wells in the final phase of the Valhall DP Abandoning Campaign in the Norwegian Sea Egil Thorstensen, Kjetil Vadset, Martin Knut Straume and Laurent Delabroy, AkerBP; Gasser Abdelal, Queen’s University, Belfast; Paul Carragher, Jeff Fulks and David Leslie Mason, BiSN Oil Tools Ltd.

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