Annulments are not as easy as one might think. It tends to be far easier to obtain a divorce than a civil annulment. There are strict guidelines that need to be followed when attempting to obtain an annulment. In receiving an annulment basically the courts (and/or the church) is stating that the marriage never took place.
There are civil annulments and religious annulments and having your marriage annulled by one forum does not mean it is annulled in both. In fact, the annulment process is separate in both a civil and religious setting.
In any event, if you are seeking an annulment, arm yourself with as much information as possible. Seek the advice of an attorney and read as much as you can about annulments. You may not be afforded the option of a civil annulment but a religious annulment is a different issue and you can talk to your clergy regarding it.