The Texas PetroIndex, an indicator of the economic vitality of the E&P industry in Texas, achieved a record high of 219.1 in September, marking the 49th consecutive month of improvement, according to the Wichita Falls, Texas-based Texas Alliance of Energy Producers.

But, the month-to-month increase of 0.10% was the smallest during 49-month-long growth period.

"Due to retreating commodity prices and a statewide rig count that is likely to peak in the coming months, this spectacular four-year growth period may be beginning to lose vitality," says economist Karr Ingham, the principal of Amarillo-based Ingham Economic Reporting and creator of the PetroIndex.

"If the September PetroIndex really is signaling the beginning of the end for this historic oil and gas upturn, one can only hope the industry will settle into a period of price stability, accompanied by high levels of exploration and production activity."

The index is a composite number made up of more than 20 oil and gas industry economic indicators and is issued monthly by the Texas Alliance of Energy Producers.