Off and on, I do contract work for oil companies and I can say with some certainty that it's a pretty hostile environment toward women.
Let me give some examples to see if I can build a picture. On the technology end of things, I used to go to the conference SEG, which a lot of deals for technology are made on the side. I've not been for the last 4-5 years, but they used to be really aggressive about their use of booth babes. For example, I remember one year where there was a vendor where I could get my shoes shined by a group of women wearing bikinis, cowboy boots, and cowboy hats while having the sales person talk to me about whatever widget they were selling. Similarly, a former coworker used to hire what were called "technical models" who were pretty women that could talk shop that they'd used to drive sales. Now, is this unique to oil? Nope. However, I felt they were pretty aggressive about it.
As far as oil rig work, that's interesting for a couple of reasons. One, roughnecking is one of the only fields left that pays extremely good money for limited amount of education. Two, most of the managers that I met did a certain amount of time working on rigs to cut their teeth and they very much viewed it as a rite of passage into upper management. I mention these two things because it turns out rig work is important both for providing wealth to those with little education as well as a path to upper management. Now, as a women, is this an inviting environment? Well, let's see; there are very few women doing it right now, so it's likely you'd be one of the only ones at the operation. Further, depending on the assignment, you could literally be trapped either in the middle of the desert or on an offshore rig with literally no where to go in case there was a conflict with the other personnel. Alternatively, you could take an assignment in a place like Saudi where you have to completely cover yourself and not drive whenever you're off compound. That sucks and every woman who enters the field knows that it sucks.
That said, would oil management be excited if a bunch of women wanted to do rig work? Absolutely. Each of the companies that I've worked with absolutely had outreach programs to attract women. However, it's hard because overall it's an extremely hostile environment. Further, it has a long term affect because the current oil culture encourages a certain amount of rig work to cut your teeth for management and if women aren't getting that then they're at a disadvantage for those positions as well.
What to do? Honestly, I don't know. Personally, I think there's a chicken and the egg problem. If there was magically a big cohort of women who wanted to get on a rig, I think many of the problems I mentioned above would be moderated. Though, certainly, disadvantages while working in the Middle East persist. However, it's unlikely that such a cohort will magically appear. Till then, part of the point of outreach programs is to create small, incremental improvement until these problems fix themselves.