The partners (XOM 40%, HES 40%, PBR 20%) tried to find a company to assume an equity stake in the project, but there were no takers.
The writing was on the wall about this project when XOM omitted any mention of Brazil in its Investor Day presentation in Mar 2011 (#msg-60789981).
p.s. HES’ share price has for a long time had zero value baked in for Brazil, so the formal end to the BM-S-22 project is certainly not a market-moving event.