OBJECTIVE The aim of this study was to determine whether older postmenopausal women with a history of bilateral oophorectomy before natural menopause (surgical menopause) have a higher risk of nonvertebral postmenopausal fracture than women with natural menopause. METHODS We used 21 years of prospectively collected incident fracture data from the ongoing Study of Osteoporotic Fractures, a coh...

In this work, we used a grain-based numerical model based on the concept of lattice. The modelling was done to simulate the lab experiments carried out on the mortar samples. Also the analytical solutions corresponding to the viscosity-dominated regime were used to estimate the fracture length and width, and the results obtained were compared with the numerical simulations. As the analytical so...

The mathematical modeling of fracture networks is critical for the exploration and development of natural resources. Fractures can help the production of petroleum, water, and geothermal energy. They also greatly influence the drainage and production of methane gas from coal beds. Orientation and spatial distribution of fractures in rocks are important factors in controlling fluid flow. The obj...

Fracture propagation, especially for fractures emanating from inclined wellbores and closed natural fracture often involves Mode I, Mode II, and at times Mode III fracture pattern simultaneously. In this paper a Virtual Multidimensional Internal Bond (VMIB) model is presented to simulate 3D mixedmode fracture propagation. To represent the contact and friction between fracture surfaces, a threed...

The onshore oil and natural gas industries of China have started a large-scale development when crude oil reserves have been difficult to recover. The stratum fracture modification is an indispensable measure to efficiently develop oil and gas fields. Hydraulic fracturing is the most important reservoir stimulation technique, but it is still faced with various problems such as the failure to fr...

Abstract: The oil recovery factor from shale oil remains low, about 5 to 7% of the oil in place. How to increase oil recovery from shale oil reservoirs is attracting more and more attention. CO2 huff-and-puff was historically considered one of the best approaches to improve the oil rate. Most previous simulation studies have been based on dual porosity, but simulation results from dual-porosity...

Due to geological reasons, fractured reservoirs are extremely heterogeneous. Modelling of these reservoirs has so far been considered complex and progress is still inadequate. This paper presents a novel and hybrid method to model discrete fracture networks in naturally fractured reservoirs. It involves investigation and systematic integration of tasks spanning cross-disciplinary areas: geologi...

The clear understanding of hydraulic fracture network complexity and the optimization of fracture network configuration are important to the hydraulic fracturing treatment of shale gas reservoirs. For the prediction of hydraulic fracture network configuration, one of the problems is the accurate representation of natural fractures. In this work, a real natural fracture network is reconstructed ...

Abstract The interaction between hydraulic fractures (HF) and natural (NF) is one of the most fundamental phenomena in fracturing. near-wellbore HF NF significantly affects fracking-related operations including injected fluid flow, proppant transport well productivity. However, nature fracturing modes, combined with hydro-mechanical coupling, poses great difficulties challenges addressing this ...