FLBK Disposal Costs

I have working interest in several wells in northern Grady County and have been charged for my share of the FLBK-Disposal Costs. I am not disputing this because it was listed on the AFE. Just curious what this acronym stands for. Have Googled it and cannot find any information about it.

Guessing that this is Flowback - Disposal Costs. When a well is completed and frac’d, the frac fluid flows back for some time and has to be disposed of properly.

Authority For Expenditure