I have heard of the theory about 'Dorrell' coming from 'D'Airelle' and indeed I believe my 'Uncle' (he was really a more distant relative) was the person who developed this theory. Unfortunately I don't think it is correct or at least there is a large element of doubt about it. Some kind of 'De' something is an obvious suggestion for the origin of the Dorrell name but most 'De' names are for locations in Britain and not France. So on balance it is most likely that the Orrell the Dorrell's come from is somewhere in Britain.
I am therefore trying to see if I can establish a connectionto Orrell. This of course doesn't mean that the Dorrell's were related to the Orrell's. They could have of course been some kind of junior branch who moved away and this branch became known as D'Orrell. But equally it could be that they were just some people who lived in Orrell and then moved elsewhere.
I don't think it is significant that the de Orrell's were not 'shortened' to Dorrell or something because the word Orrell would still make sense in Lancashire. Whereas in Worcestershire no one would know Orrell and so it would tend to get shortened.
You see there is no connection as far as I know between the medieval Darell/Dayrell family and the modern family, or indeed the medieval Orrell's and the Dorrell's. There is a gap of 100 to 200 years between the medieval Darell/Dayrell (and Orrell's) and the Dorrell's & also they are in different locations - Worcestershire & area.
So I am looking for, but not necessarily expecting to find, links from the Orrell family or Orrell area to Worcestershire & that area.