HOUSTON (Reuters) - Buoyed by concluding a big pay raise for steel workers last month, a United Steelworkers union top negotiator squares off on Wednesday against oil companies seeking to win a 24 percent wage hike for 30,000 refinery and chemical employees.

The stakes are high for the union and oil industry, which scored big profits last year from refining and chemicals. The talks are the first since 2015 when a stalemate led to rolling strikes that sent more than 7,000 workers off their jobs at 12 U.S. refineries and three chemical plants.

The union’s co-negotiator, USW International Vice President Tom Conway, is a 6-foot-tall former Bethlehem Steel millwright with a reputation as a bulldog, according to associates. He faces negotiators from Royal Dutch Shell Plc’s U.S. arm, which has represented the oil industry in talks since 1997.

Conway led USW negotiations last year with U.S. Steel Corp that got hourly employees a 14 percent raise over four years.

The USW is seeking a three-year agreement with the oil industry that would replace the pact that expires on Feb. 1. The union’s proposals include an 8 percent annual wage increase for each year of the contract. Union members with four years’ experience earn about $40 an hour.

The contract covers 30,000 workers at plants operated by Shell, Marathon Petroleum Corp, BP Plc, Exxon Mobil Corp, Valero Energy Corp, and smaller refiners such as HollyFrontier Corp and Delek US Holdings Inc.

Refiners enter talks enjoying high profits from near-full plant utilization rates and record product exports that have lifted margins.

“We look forward to a productive set of talks with the USW and will bargain in good faith to reach a mutually acceptable agreement,” said Shell spokesman Ray Fisher.

Fisher declined to discuss the terms that the company would offer.

In addition to higher pay, the union is seeking improved job security, health and safety conditions including the number of consecutive days that employees must work, officials have said.

Conway, son of a union member and a U.S. Air Force veteran, declined to be interviewed. But in remarks at a union convention in 2017, he described his negotiating philosophy as a battle with corporations to get the benefits workers deserve.

“Collective bargaining makes them sit and share with us what we rightfully have a right to demand,” he said at the Las Vegas meeting. “Be ready for it, because the fights will come whether we want them or not. But when the fights do come, we can win those fights.”

Conway helped lead workers through the 2015 strike, triggered when oil-company negotiators failed to ask for an extension of talks after the prior contract expired, said former USW International Vice President Gary Beevers.

“He is an excellent negotiator and an asset to the team,” Beevers said of Conway. Conway is part of a two-man team with USW National Oil Bargaining Chairman Kim Nibarger.

Failure to reach a deal could have widely felt impact. During the 2015 strike, the 12 refineries cut production by as much as 50 percent, reducing gasoline supply during the spring build-up during the summer driving season.