A workflow for flow simulation in shale oil reservoirs: A case study in woodford shale

Abstract

In recent years, with new technologies of long horizontal wells and staged hydraulic fracturing, the development of unconventional oil and gas reservoirs (i.e., shale gas and shale oil) has gained significant momentum. Due to extremely low permeability, these unconventional formations cannot be produced economically without significant stimulation. In the current research, the workflow for shale reservoir history matching that can be used for other shale resources producing from either condensate or oil reservoirs is developed. Production data and well geometry data for nineteen wells were available in Woodford shale. During this work, using the available data, single well simulation models for all the individual wells were constructed and then models were tuned to match the historical data. It has been shown that the fracture half length, shear fracture distribution and the interaction between matrix and fractures should be captured. Also, the results showed that fracture half-length can be longer than 2,000 ft, but the permeability of the fracture is dependent on how far the fracture is from the well. It was found that for multiple well history matching, fracture half-length and the interaction between the wells are the most important factors. Using multiple history matched models, it was shown that multiple models with different fracture distributions could capture the historical data, but they exhibit different future predictions.

Numerical Modeling of Shale Oil Considering the Influence of Micro- and Nanoscale Pore Structures

“…The viscosity of the oil within the interface region differs from that within the bulk region. Specifically, in nanopores embedded within organic matter, the substantial interactions between oil and the pore walls result in an elevated viscosity for the interface oil compared to the bulk oil viscosity [25][26][27]. In contrast, for nanopores in an inorganic matrix, the interface oil viscosity is smaller than the bulk oil viscosity.…”

Multi-Scale and Multi-Dimensional Imaging of Mineral Matrix Pore-Fracture Networks in Lower-Thermal-Maturity Lacustrine Shale: Examples from the Paleogene Shahejie Formation, Bohai Bay Basin

“…Both FESEM images from 2D surfaces and Ar-ion-beam milling of shale samples allow examination of mineral matrix pores and microfractures that are strongly controlled by mechanical and chemical diagenesis. 17,44 Several typical shale pore-fracture classification schemes have been proposed. 12,17 The shale mineral matrix pore and fracture types described in this study follow that of Loucks et al 18 and Zhu et al 41 Loucks et al 18 suggest that pore types associated with mineral grains can be subdivided into interparticle pores that are located between grains (e.g., clay flakes, calcite and quartz, and larger detrital grains) and crystals (e.g., silica microcrystals, pyrite, and pyrite framboids) and intraparticle pores that are found within grains.…”

Impact of Osmotic Pressure on Seepage in Shale Oil Reservoirs

“…Shale oil, characterized as hydrocarbons and various organics stored within organic-rich shale formations, exhibits features such as low porosity, low permeability, and a rich organic content [3]. Unlike conventional reservoirs, shale oil typically lacks stable natural production, necessitating large-scale hydraulic fracturing to enhance near-well permeability and thus boost well productivity [4]. Given the pronounced capillary effects in the micro-to-nano scale pores of shale reservoirs and the significant presence of fracturing fluids in the complex fracture networks postfracturing, these fluids can be imbibed into the matrix pores via capillary forces, displacing the crude oil into hydraulic fractures [5].…”