It usually takes a Fortnight to a Month. Interview on Skype/Telecom and a face to face interview on need basis. Then comes the background verification and finally the suitable candidates are provided with an Offer letter.
You need an internal referral just to get in the door at KBR. I was told after being hired that I was picked out of 40,000 resumes...obviously it isn't an easy step to be hired internationally by KBR.