An Assessment of Hydraulic Fracture and Geomechanical Properties on the Compaction and the Productivity of Marcellus Shale Horizontal Wells

Declining pore pressure, with reservoir depletion, increases the net stress leading to compaction of the Marcellus shale damaging the formation and hydraulic fracture properties. To accurately predict gas production as net stress increases, geomechanical and fluid flow simulations are required. By analyzing data from Marcellus Shale Energy and Environment Laboratory sites, researchers were able to investigate the impact of shale compaction on gas production. The study was focused on how shale mechanical and fracture properties, as well as operating conditions, influence the productivity of horizontal Marcellus Shale wells with multi-stage fractures. Simulated model results showed that including the compaction in the model resulted in more accurate prediction of production from horizontal wells with multiple hydraulic fracture stages in the Marcellus shale. Young's modulus was observed to have a greater impact on the geomechanical factors and the production performance than for Poisson's ratio. Furthermore, Due to the high gas production rate during early production, compaction has a more dramatic impact which diminishes as production continues. 1. INTRODUCTION The Marcellus Shale is the largest shale play in the United States, covering a vast geological area of 95,000 square miles. This shale formation, known for holding the largest natural gas deposits in the U.S., is predominantly found in the Permian Basin. The Marcellus Shale, situated in the Appalachian Basin, stands out as the most prominent natural gas-producing play in the country and spans across six states: New York, Pennsylvania, Ohio, West Virginia, Maryland, and Virginia. Characterized as an abundant fine-grained sedimentary rock formed through the compaction of silt and clay-size mineral particles, the Marcellus Shale exhibits the ability to fold into thin layers. Being over 400 million years old, this formation ranks among the largest nationwide and is a top producer of natural gas in the U.S. With the implementation of modern exploration techniques like hydraulic fracturing and horizontal drilling, the Marcellus Shale is estimated to hold around 400 trillion cubic feet of gas, attracting significant attention from the oil and gas industry in the U.S.