Studies of Influencing Factors for Shale Gas Reservoir Performance

Shale gas resource plays a significant role in energy supply world-widely. As shale has extremely low permeability, it is impossible to obtain economical production without horizontal wellbores and hydraulic fracturing. Additional elements, such as free gas in porous media and absorbed gas in organic matter and multiple scales of pores, further complicate fluid flow in shale formations. Under this scenario, reservoir performance will be affected by many parameters. The objective is to understand the most influencing parameters for shale reservoir performance, in term of long term or short term production rate or cumulative production. To this end, these parameters were classified into two categories: a) reservoir properties and b) hydraulic fracture; the method of experimental design is used to conduct sensitive analysis. Sensitivity analyses were conducted on each parameter and combination of parameters in each category and combination of all parameters. Objective functions were taken using production rate and cumulative production at one year, five years, ten years, and twenty years. Results show that each parameter has a changing role in influencing the reservoir performance, and hydraulic fracture properties have dominating influence for early production, and reservoir properties have increasing influence on the later stage of shale gas production.