Judge Rules on Definition of Deep Well

State law provides different rules for deep and shallow gas wells. Deep wells are subject to pooling and field rules, and the spacing required between wells is different, depending on whether they are deep or shallow. The Oil and Gas Conservation Commission has authority over deep wells, while the Shallow Gas Review Board hears appeals on shallow gas wells.

Shallow wells are those that are drilled no further than 20 feet into the top of the Onondaga formation. (The 20 feet is needed to drill the "rat tail" and complete the well, but no gas can be produced in the Onondaga.) The dividing line between deep and shallow wells never was much of an issue until development of the Marcellus Shale, which lies directly on top of the Onondaga formation. Drilling of horizontal wells in the Marcellus is preceded by a vertical well and a rat tail that usually goes more than 20 feet into the Onondaga. The Onondaga isn't produced, and after the rat tail is logged out it can be filled with cement.

The question arose as to whether a well drilled more than 20 feet into the Onondaga is a deep well, and subject to deep well spacing, or a shallow well. The issue was originally taken to Supreme Court on a writ of prohibition, which sent it to Judge Murensky in McDowell County. Judge Murensky went with a strict interpretation of the statute and said that if a well went more than 20 feet into the Onondaga it is a deep well, even if only the formations above the Onondaga is produced. You can see his opinion here.

An effort was made during the last Legislative session to change the definition to allow drilling into the Onondaga without converting the well to a deep well. A similar effort may be made in 2011.