I am a female working in the field in the oil and gas industry. I ultimately would like to progress to a more senior role which could possibly transition to an office role. I am thinking of shaving my head for a cancer fundraiser. This would be a one time thing (I would let my hair grow back), but from previous experience it takes about 1.5 years to return to a socially acceptable length. My concern is that with this volatile economy I could get laid off in that period, in which case I would be interviewing for a new role, or could be considered (and possibly passed over) for progression within my company. Will this impact my chances of career progression/how people see me as a professional?
Will this impact my chances of career progression?
If by that you mean:
"Will people consider this hair style unprofessional?"
Then unfortunately the answer is: Some will. And because of that it could negatively impact your reputation at work and thereby affect your career at that company. Shaving your head is a counter-cultural statement, even if you do it for charity. It's meant to draw attention and be confrontational and that's pretty much the opposite of a professional dress code. While the days of the ultraconservative business look are a couple of decades behind us, there are still very clear standards of dress in the corporate world. Workplace culture is changing and unnatural hair colours are slowly becoming acceptable in more industries but this is still very much a matter of knowing your industry and company. From the outside it's difficult to tell whether a company or industry will be open to non-standard hair styles. In advocacy non-profits employees will typically dress conservatively to avoid confirming to stereotypes and keeping the focus on their message not their staff.
In Western cultures a shaved head is an unusual style for women and much less accepted than it is for men. I can guess at the reasons behind that but it's a topic for another site. Suffice to say that it's outside the norm and because of that many companies will consider shaving your head as a woman a strange but ultimately a personal choice. Sadly, some will hold you accountable for a personal choice that impacts your work or appearance and some may believe that looking professional is too low on your list of priorities. Whether your company, your management or your clients will consider shaving your head unprofessional is something only you or your manager can try to predict.
With that in mind, I strongly suggest that you discuss this with your manager. He'll typically have been in your industry longer and can more accurately guess how your work environment will react. If you detect even the slightest hesitation on his part or notice that he's looking for a way to discourage you while realising that he shouldn't interfere with personal choices, don't do it.
Ultimately, oil and gas isn't known for being a progressive industry and I would advise you to find another way to champion your cause. You may spend the rest of your career wondering if this had a negative effect. There are many other ways of making a statement or supporting a charity.
Since this is a volatile topic and I don't want to be misinterpreted I want to make it clear that I have absolutely no problem with a woman opting for a shaved head, whether temporarily or permanently. But I have to acknowledge that my opinion is not shared by all, that beauty standards differ for men and women and that the choices we make can affect how others view us, even subconsciously. It is lamentable that a shaved head is not always considered an acceptable hairstyle for women but that is the reality of the world in which we live. It's people who are willing to challenge society's norms that end up changing them for the better but we need to acknowledge that doing so can have real downsides. I wish I could give a different answer here but ultimately, shaving your head can have a negative impact on your career.
I honestly don't think shaving your head for a cancer fund-raiser is unprofessional in any way. The only issue you might face with with your management is how you might be perceived by your customers.
Are you in a position where you interface with customers a lot?
I also question your assessment that it will take 1.5 years to grow to a 'socially acceptable length'. That is 9 inches, and certainly many, many women have perfectly acceptable hair styles shorter than 9 inches.
If I were a hiring manager I would be impressed if someone shaved their head for a cancer fund-raiser.
It is for cancer awareness. You should talk to people at work and tell them you did it for cancer awareness. Be proactive as some people may fear you actually do have cancer. I think most people would view it as noble and not think any less of you professionally.
If you do interview you should have a chance to explain why your hair is short. And again I think they would view it as noble.
Another part is how you look with a shaved head. Demi Moore looks fine shaved.
I did the opposite for no noble cause. Made a stupid bar bet that I would grown my hair to a man bun. It is a total pain and for sure I would cut it if I was looking for a job. In my job I never come in contact with customers.
If you aren't willing to just do it, take a stand, and let the dandruff fall where it may (which would be my attitude...) there is one pluperfectly obvious answer: Ask Your Boss, Not Us. Career effects if any will be 173% workplace-, industry-, and role related, and your boss can make a better guess about local customs and customers than we can.
Note that on many cultures covering the head is entirely acceptable... but it seems to me that if you aren't willing to confront people with your shaven cranium there isn't a lot of point to the exercise. If you just want to donate your hair, Locks Of Love doesn't require you go all the way to bare scalp.
Side-comment: Remember that after shaving or getting a buzz-cut, sunburning your scalp may be a risk. Be careful until you know your limits.