The rock mechanical properties of lacustrine shales: Argillaceous shales versus silty laminae shales

Reservoir Petrofacies Predicted Using Logs Data: A Study of Shale Oil from Seven Members of the Upper Triassic Yanchang Formation, Ordos Basin, China

“…Many authors also define petrography based on a combination of core analysis characteristics, petrographic features (grain size, sorting, mineralogy, and pore type), and well logging characteristics [2, 44,45]. Our petrofacies classification scheme focuses on four key criteria of shale reservoirs: porosity and pore types determine the reservoir's storage performance and fluid endowment state [46,47], TOC determines the reservoir's hydrocarbon potential [48,49], and brittleness index determines the reservoir's remodeling ability [50][51][52]. Venier et al identified five petrofacies through core hand specimens, mineralogical composition obtained from XRD experiments, TOC, and logging responses [15].…”

An Experimental Study and Machine Learning Modeling of Shale Swelling in Extended Reach Wells When Exposed to Diverse Water-Based Drilling Fluids

“…The primary objective of extended reach wells is to access remote or hard-to-reach hydrocarbon reserves while minimizing the number of surface locations and drilling costs. , One of the significant challenges associated with extended reach wells is the risk of shale swelling when exposed to different water-based drilling fluids (WBDFs) . Shale swelling occurs when the shale formations encounter WBDFs, leading to the expansion and deformation of the shale rocks. − Shale is composed of clay minerals, which can absorb water and expand. − The interaction between shale and drilling fluids can have far-reaching consequences, including wellbore instability, formation damage, lost circulation, and decreased drilling efficiency. − …”

Effects of Shale Pore Size and Connectivity on scCO2 Enhanced Oil Recovery: A Molecular Dynamics Simulation Investigation

“…Under the current situation of increasingly depleted resources, traditional oil resources are gradually unable to satisfy the increasing energy requirement. − It is reported that shale oil accounts for a large proportion of the total energy supply as the conventional oil production gradually declines in recent years. Therefore, the development of shale oil plays a crucial role in alleviating the current problem of energy shortage. , Shale reservoirs are typical multi-scale porous media, in which the nanopores are extremely developed and have ultra-low permeability, making it difficult to exploit. − Multifarious approaches have been employed to improve the recovery of shale oil, such as chemical flooding, gas injection, thermal recovery, and smart water flooding. , Despite extensive attempts on thermal recovery, chemical flooding, and water flooding, applications are limited due to abominable reservoir conditions, high costs, and damage to the formation. , Gas (such as CO 2 , N 2 , and natural gas) injection-enhanced oil recovery is gradually appreciated due to their environmental protection and high efficiency. − Compared with other gases, CO 2 is supercritical under high-temperature and pressure conditions in shale reservoirs, possessing tremendous advantages and unique properties, such as a high diffusion rate and favorable dissolution capacity. , Because of these properties, CO 2 injection is regarded as an extremely promising EOR method. Meanwhile, CO 2 EOR realizes the utilization and sequestration of carbon, reducing CO 2 gas emissions and thus mitigating the greenhouse effect. − …”