The Aberdeen-based company said the three-year deal had been signed with an unnamed blue-chip international oil company.
It added that more than 100 new jobs would be created as a result of the contract, with a further 20 posts retained.
The staff will be based at Wood Group's offices in Iraq and Dubai.
David Buchan, from Wood Group division WGPSN, said: "This major contract builds on our strong partnerships with clients in Iraq.
"Iraq is an area where we see significant growth opportunities for our broad service capabilities and building our presence in this region is a key objective for us.
"This is reflected in our creation of another office in Dubai, which adds to our presence in the Middle East and our commitment to developing local talent, creating job opportunities and building relationships with the supply chain in Iraq."
Last month Wood Group won a multi-million dollar subsea contract with BP, to provide engineering services in the Gulf of Mexico, UK and Norwegian continental shelves and offshore Azerbaijan.
It was the second major BP contract secured by the company this year.
Oil services giant Wood Group has won a $90m (Â£60m) project management contract for an onshore facility in Iraq.