Low producing (marginal) wells contribute greatly to the nation's energy needs, but they can frequently serve as cautionary tales for Operators who fail to educate themselves regarding the nuances of the Production in Paying Quantities doctrine. This doctrine, requiring that the production from a well must exceed its related expenses has been the law in Texas for several decades. An analysis of this doctrine, from its historic roots to its contemporary application reveals a great deal of uncertainty regarding its scope and the methods of its application.