The Pioneering Spirit, owned by Allseas, used its vast lifting capacity for the first time to remove a platform for scrappage.
It carried out the operation on Monday, and is taking the platform to a Norwegian yard.
The ship's first lift was in the Norwegian sector of the North Sea.
After the fitting of additional lifting equipment in the Netherlands, the ship is booked later this year to start work on platforms in the UK North Sea.
Its arrival begins to open up the market for scrapping ageing North Sea equipment, which is estimated as being worth around Â£40bn in the next four decades.
The Pioneering Spirit was built in Singapore and fitted out in Rotterdam.
It is also capable of lifting the steel jackets on which platforms have been sitting since the 1970s.

IVF should be offered after two years of failed attempts, not the current three, says the National Institute for Health and Clinical Excellence.
And the upper age limit should rise from 39 to 42 in England and Wales.
Some fertility experts fear the guidelines may not lead to changes because they are not binding.
In the past, NHS trusts have struggled to find the money to meet the IVF recommendations.
A report in 2011, showed one in four NHS trusts offered the full three cycles. Each round costs Â£3,000.
Around one in every seven heterosexual couples in the UK who are trying for a baby experience problems conceiving a child.
In 2011, nearly 14,000 women became pregnant through IVF.
The new guidelines, which apply to England and Wales only, state that women aged between 40 and 42 should be offered one cycle of IVF as long as it is their first time and they have enough eggs.
The age limit for NHS-funded fertility treatment is 38 in Scotland and 39 in Northern Ireland, according to the Human Fertilisation and Embryology Authority.
Tim Child, who helped devise the guidelines and is the director of the Oxford Fertility Unit, said the decision was not taken lightly.
"When a woman reaches her mid-30s her fertility begins to decline, even more so from her late 30s.
"However, many women do conceive naturally in the 40 to 42 year age group. But for those who can't, and who have been diagnosed with the medical condition of infertility, then improvement in IVF success rates over the last decade mean that we are now able to offer cost-effective treatment with a single IVF cycle."
Medical advances mean this age group has similar success rates to that of younger women when the original guidelines were introduced in 2004.
The update still recommends women under 40 are offered three cycles of IVF.
Some fertility experts raised concerns that the expanded recommendations may not happen in reality.
Dr Sue Avery, a spokesperson for the British Fertility Society and from Birmingham Women's Fertility Centre, told the BBC: "It's good that there's the possibility there, but the funding does not match.
"I can't see any prospect of it happening immediately. Our biggest concern is hanging on to the funding we've got."
The guidelines also introduced rules designed to significantly reduce the number of twins and triplets being born.
Multiple births, a consequence of implanting more than one embryo to increase the odds of success, are one of the biggest risks associated with IVF for both mother and child.
Twins tend to be born smaller and earlier - triplets even more so.
Women under the age of 37 should have only one embryo transferred in their first cycle.
Subsequent cycles, and cycles in older women, can consider implanting two embryos.
Most couples should no longer be offered intrauterine insemination on the NHS, as its results are no better than sex.
However, when there is not an option - such as same sex couples and patients with certain disabilities - it would still be an option.
Dr Tony Falconer, president of the Royal College of Obstetricians and Gynaecologists, said fertility problems could have a devastating effect on couples.
He welcomed the guidelines, but warned there were risks attached.
"The recommendation that IVF treatment be made available up to the age of 42 provides more choice for women, but they should still be aware of the increased risks associated with pregnancy at advanced maternal age," he said.
One of the world's biggest ships has begun a new era for the North Sea oil and gas industry.
[NEXT_CONCEPT]
Couples struggling to have a baby should get fertility treatment more quickly and older women should gain access to IVF, new NHS guidelines say.