Is it possible for me to file an immigration papers for my wife by myself?

If you are asking whether you and your wife may file a marriage-based adjustment of status application package by yourself and without engaging an immigration attorney, the simple answer is "yes." Engagement of an immigration law firm would be wise, however, if you and your wife are not very clear about all of the legal requirements and documentary evidence that will be required, and this is especially true if there may be any details that create complications (such as uncertainty about birth documents, previous divorce records, a history involving a criminal arrest, etc.). The adjustment of status process can be significantly more complex than it appears, with risks of delay, denial and other consequences for the unwary. Aside from the relatively obvious advantages of being represented by a lawyer to assure that the case is prepared and pursued properly, there are other advantages too, and these include having USCIS send notices to two addresses (yours and the attorney's), having an attorney attend an adjustment of status interview with the couple to assure that the USCIS adjudicating officer focuses only on legally relevant matters, and having access to the liaison process between the American Immigration Lawyers Association and the USCIS (especially useful where the USCIS makes a mistake or presents an unusual delay).