If you haven’t seen it here is a link to the drilling permit PRI filed for the most recent horizontal well in that section that crosses the area you described. It shows the unit is covered by a production sharing agreement. http://webapps.rrc.texas.gov/DP/publicQuerySearchAction.do?countyCode=371&apiSeqNo=40187
The documents listed at the bottom of the last page of that permit include a long notifications list indicating you may be part of a large group of potential mineral owners that haven’t been accounted for and may explain the time it is taking PRI to sort things out.
Here is a link to the plat PRI filed with that permit that has the area you described you mineral interest being located in marked as Tract 5 40.41 acres.
Coleman Co. - Sec. 1, Blk 48 TS8.pdf (1.4 MB)