Energy industry conferences are notorious for producing plenty of swag - usually things like notebooks and miniature flashlights that collect dust at the bottom of a briefcase.

But when Halliburton officials know they'll be speaking in front of an audience of mostly women, they use a different type of giveaway: containers of nail polish and lipstick - in the company's signature "rig crew red" - complete with the company logo.

While it may seem like a token gesture, officials at the oilfield services company say it represents something broader: a concerted effort to try to dispel the boy's club image that has permeated the energy sector and instead promote the company as a destination for women.

"You'd be surprised - they really spark that conversation," said Lisa Finch, Halliburton's manager for global diversity and inclusion. "We work in a predominantly male industry. We want to show there's a softer side."

Halliburton is joining other industry players in trying to make inroads with female job candidates by beefing up company presence at college campuses and women's professional groups, among other steps, to increase their appeal.

"You're going to put on work boots and jumpsuits and go out into the field, which is not something young women have been raised to expect to do," said Jamie Belinne, assistant dean of career services at University of Houston's Bauer College of Business.

But as oil and gas companies face what they call the "great crew change" - an onslaught of baby boomer retirements poised to place a dramatic strain on the industry's workforce - there's a growing recognition that the sector will need all the help it can get to close the employment gap.

"We're seeing we have a large opportunity here to maximize our workforce," Finch said. "It's no secret than in the past the industry overall has been predominantly male. We haven't been leveraging the talent pool out there."

Only 19 percent

Women comprise about 19 percent of the oil and gas and petrochemical workforce, even though they represent more than 45 percent of U.S. employment, according to a study published earlier this year by the American Petroleum Institute, an industry association. The shortfall exists in every job type within the sector except office and administrative support.

The API study estimates that the loss of retiring workers between 2010 and 2030 will create more than 579,000 job opportunities within the energy sector.

"The demand for talent is far outstripping supply," said Carolyn Stewart, North America regional business development manager at NES Global Talent, a staffing company with a focus on the energy sector. "The message companies are putting out is 'we need women; we need everyone.' "

That hasn't always been the case. In the mid-1980s, a collapse of oil prices set off an industry slump that made it difficult - and often undesirable - to get a job in the energy sector.

But the industry renaissance that unfolded over the last decade has prompted a glut of job openings and a shortage of workers, all at a time when women represent about 57 percent of college students, according to the most recent federal data. Industry officials say they don't want to run the risk of losing qualified candidates to other sectors.

Making changes

"When they realized they had to hire again, suddenly more than half of their candidates were women," Belinne said. "If they want access to that talent, they'll have to make changes."

That's already starting to happen, said Belinne whose help connects employers with graduates from the University of Houston's business school.

Until about five years ago, most of the energy sector's recruiters were men, she said.

Now, a growing number of women working as recruiters are making female prospects more comfortable with the industry.

Energy companies also are sending high-ranking women to speak at campus events to demonstrate the potential for women to advance in the energy sector.

And more companies are offering employees on-site day care, generous maternity leave policies, flexible work schedules, and a greater say when it comes to relocation.

Family friendly

Those changes are welcomed by male and female workers alike but are particularly attractive to young women considering how they'll balance the demands of work and family as they decide where to launch their careers. "The companies that are able to demonstrate they're family friendly have more students to chose from," Belinne said.

Companies also are setting goals for hiring and advancing female workers.

BP, for example, wants women to comprise 25 percent of its group leaders by 2020, up from 18 percent now, said Linda Emery, the company's global head of talent attraction and candidate experience.

Other companies have set similar targets and are enacting requirements that a minimum number of women or minorities be considered for each job opening.

It makes for good public relations, but companies also believe they can improve the way they're run if they have a diverse group of thinkers within their ranks. "It's critical to us we attract the best talent we can," Emery said. "That talent comes in male and female form."

Competition for women in engineering is fierce. "They are perceived to have skills which are of value to many different industries," Emery said. "What we find is we're competing not just with engineering firms and energy companies but also with investment banks and consumer services. It's a very sought after group of individuals. If I had a daughter I'd be saying 'study engineering.' "

But men still dominate the energy sector's core academic disciplines. Women earned about 40 percent of four-year science degrees in 2011, the latest year federal figures were available. They earned 20 percent of engineering degrees and just 15 percent of petroleum engineering degrees that same year.

"It's just the reality you have to deal with," said Vita Como, senior director of the engineering career center at University of Houston. "We have to reach back to middle school to start (convincing) young women of the fact that they're smart and they can do it."

Some feel unwelcome

Energy companies are partnering with universities and high schools to promote awareness about engineering and science careers, and they're hosting workshops and competitions for even younger students to stir interest in the fields among girls. "We've introduced them to the discipline while giving them the Halliburton brand," said Finch, the diversity manager there.

The message worked for Sofia Olivas, a Halliburton engineer working in South Texas who was recruited at University of Texas Pan-American before she graduated in 2010. "They give you a lot of opportunities to advance your career," Olivas said.

The industry is trying to develop those opportunities partly by creating employee resource groups - internal networks of workers within a company - focused on career development for women.

"It helps with mentoring and sponsorship," said Tamara Morytko, vice president of the southern geomarket at Baker Hughes. Though not every energy company has them, those that do often use them as a recruiting tool. "It's a selling point for any company," Morytko added.

Still, it will take more work to close the industry's gender gap.

A quarter of female engineers in the energy sectors say they don't feel welcome in the industry, according to a survey last year by NES Global Talent.

"I feel welcome, for the most part, however there have been occasions in the past - especially offshore - that I have felt regarded as a novelty and not taken seriously," read one response in the survey.

The same survey of 272 respondents found that nearly half of the female engineers felt they didn't get the same amount of recognition as their male counterparts, and nearly 20 percent were considering leaving the industry.

"Sometimes women sell themselves short," said Tonya Williams, Shell Oil Co.'s development lead for Auger, a platform in the Gulf of Mexico. "They don't always feel they have confidence within a male-dominated organization."

Advancement opportunities may be limited, to an extent, since the path to leadership at oil and gas companies often requires a stop in a dangerous or exotic location abroad.

"There's still a lot of companies where you need to be open to suddenly relocating to Nigeria," Belline said. "Men are still more likely to take those jobs. "

Even when women do advance in an energy company, it's rare to see them leading a core business.

A list of the 50 most powerful women in the oil and gas industry, published earlier this year by the non-profit National Diversity Council, was dominated by corporate counsel, marketing executives and human resources directors - not leaders in drilling, exploration or production.

"It's still pretty rare to have a woman running a core business division of an oil company or a service company," said Janeen Judah general manager of Chevron's southern Africa business unit, who serves on the board of the Society of Petroleum Engineers.

Judah said the workplace has changed dramatically since she began her career in 1980. "I was going to the rigs, and there was open hostility by some people," Judah said. But the industry's acceptance of women hasn't grown at the pace she expected. "It's a lot slower than I thought it would be," she said. "I'm still surprised at the number of meetings where I'm the only woman."