Unlocking the Potential of Monterey Shale Resource: An Analysis of Geological Characteristics, Completion Techniques, and Production Behaviors

Abstract

Over the last thirty years, technology used to produce hydrocarbons has grown exponentially. With the optimization and combination of technologies such as horizontal drilling and hydraulic fracturing, the ability to produce low-permeability or tight hydrocarbon-bearing rocks (shale formations) which were once deemed economically impractical has now become a reality. However, these technologies which have made hydrocarbon production from unconventional reservoir possible have not been implemented in California's Monterey Shale Formation for its wide scale exploitation. Also, due to the relatively short time period of these technological advancements, there seems to be limited research that provides a comprehensive comparison of these three major U.S. analogous shale plays (i.e. Bakken, Eagle Ford, and Monterey) for gaining better understanding on their potential use in future exploitation of Monterey Formation. First, using publically available data, a comparison of key geological characteristics, completion techniques, and production behaviors of Bakken, Eagle Ford, and Monterey shale plays is presented. Monterey shale is very young and geologically heterogeneous compared to Eagle Ford and Bakken but holds significantly more reserves. Compared to Bakken and Eagle Ford, oil viscosity in Monterey shale is significantly higher and one can also notice that Monterey oil production has declined over the years. Monterey shale has a field dependent completion (pattern spacing and fracturing stage) strategy. Second, the similar analysis is expended to three Monterey specific oil fields (M, N, and R) that are located in the San Joaquin basin (SJB) of California. A detailed diagnosis of the production behaviors of both the horizontal hydraulically fractured and horizontal non-fractured wells present in the R Field shows that actually non-fractured horizontal wells are more productive which reinforce the needs of a new completion as well as new enhanced recovery strategies that could assist in future development of California's Monterey shale resource while complying with the toughest hydraulic fracturing regulations in the nation. Though water use per hydraulic fracturing job is relatively low, nearly all fracturing water use in California is in regions of extremely high water stress. The potential use of oilfield-produced water for preparing fracturing fluid formulations can also assist industry in unlocking the potential of Monterey shale without putting burden on precious fresh water resources of the region.