Mining Effects on Gas and Oil Wells Pad NV-35 Field Experiment Field Monitoring

"The most significant study on the effects of longwall mining on gas and oil well integrity was completed by a consortium of coal and shale gas industry participants. A field study was conducted in 2013 and 2014 and is referred to by its location on Well Pad NV-35. The experiment site was located at the CONSOL Enlow Fork Mine in Washington County, Pennsylvania.The experiment was completed to verify John T. Boyd Company (BOYD) calculations and studies completed under contract by for the Pennsylvania Department of Environmental Protection Gas Well Pillar Study Update. The findings of the original study were presented by BOYD at the 32nd Conference, while numerical analysis of the Well Pad NV-35 field study was presented by Dr. Su at the 35th Conference.This paper addresses the findings of the experiment and how it confirmed the conclusions of the original study.INTRODUCTIONA field study was conducted in 2013 and 2014 by a consortium of coal and shale gas industry members to test the effects of longwall-induced ground movement on the stability and integrity of wells drilled through a gateroad abutment pillar. The project was initiated to test initial John T. Boyd Company (BOYD) findings of the Gas Well Pillar Study Update (Scovazzo and Moran, 2014), completed for Pennsylvania Department of Environmental Protection, Bureau of Oil and Gas Management (PDEP). Background and initial findings on this project were presented at the 32nd Conference (Scovazzo and Moran, 2012). The field work and numerical analysis were spearheaded by CONSOL Energy, Inc. (CONSOL) with participation by Chevron, EQT, Noble Energy, Range Resources, Marcellus Shale Coalition, and the Pennsylvania Coal Alliance.Dr. Wen H. Su of CONSOL was the leader of the field experiment with input from the participants. Dr. Su also completed numerical analysis of the results and model casing deformation. Analytical results were presented by Dr. Su at the 35th Conference (Su, 2017)."