The company will acquire G&S from Calibre Group for an undisclosed sum.
The acquisition comes only six months after DRA agreed to acquire Perth-based engineering firm Minnovo.
DRA said the latest deal continued its rapid expansion in the Asia Pacific region.
G&S has offices in MacKay, Brisbane and Perth and employs around 1000 people.
The company has experience encompassing the entire project lifecycle from construction, through maintenance and optimisation to final decommissioning and deconstruction of a project.
DRA Asia-Pacific managing director Greg McRostie said the acquisition was in line with the company's growth strategy.
"We have been working closely with them for over a year now and I am delighted they will be joining the DRA group," he said.
"Australia is a key market for DRA and this acquisition gives us a well-established maintenance and optimisation platform as well as a greater presence in the region, while broadening the scope of services we can offer our clients.
"The management team at G&S has a strong track record and relationships with a number of Australian resources companies, and we look forward to working with them and the broader G&S team as we grow our business."
DRA was advised by Azure Capital and K&L Gates.