I usually don't distinguish between "multiple orgasms" that are close together and really long ones. My Man has a way of making my orgasms last a really long time. My record (he was looking at the clock, I was... busy) was eight minutes. I have NO idea if it was one orgasm or a series of them. But, one orgasm or a close series of them usually lasts between one to three minutes.
In terms of separate
distinct orgasms, I can have them, singly, for about 15 minutes to a half an hour, if we're constantly stimulating. Then I can go back and have more.
We've cut back on the frequency of sex, lately (from a high of 6-12 times a week, to about 6-8 times a week, usually in clusters of 2 or 3 times over a 36 hour period) I find I am able to orgasm more easily. (cross fingers.)
Is that what you are asking?