This paper presents an improved understanding of coupled hydro-thermo-mechanical(HTM) hydraulic fracturing of quasi-brittle rock using the bonded particle model(BPM) within the discrete element method(DEM). BPM has be...This paper presents an improved understanding of coupled hydro-thermo-mechanical(HTM) hydraulic fracturing of quasi-brittle rock using the bonded particle model(BPM) within the discrete element method(DEM). BPM has been recently extended by the authors to account for coupled convective econductive heat flow and transport, and to enable full hydro-thermal fluidesolid coupled modeling.The application of the work is on enhanced geothermal systems(EGSs), and hydraulic fracturing of hot dry rock(HDR) is studied in terms of the impact of temperature difference between rock and a flowing fracturing fluid. Micro-mechanical investigation of temperature and fracturing fluid effects on hydraulic fracturing damage in rocks is presented. It was found that fracture is shorter with pronounced secondary microcracking along the main fracture for the case when the convectiveeconductive thermal heat exchange is considered. First, the convection heat exchange during low-viscosity fluid infiltration in permeable rock around the wellbore causes significant rock cooling, where a finger-like fluid infiltration was observed. Second, fluid infiltration inhibits pressure rise during pumping and delays fracture initiation and propagation. Additionally, thermal damage occurs in the whole area around the wellbore due to rock cooling and cold fluid infiltration. The size of a damaged area around the wellbore increases with decreasing fluid dynamic viscosity. Fluid and rock compressibility ratio was found to have significant effect on the fracture propagation velocity.展开更多
Business Process Modeling (BPM) is a mechanism that separates all business aspects from the underlying technological and implementation features of a system. The aim is to capture an organization’s processes and achi...Business Process Modeling (BPM) is a mechanism that separates all business aspects from the underlying technological and implementation features of a system. The aim is to capture an organization’s processes and achieve its business objectives. Currently, there are many solutions for Business Process Modeling and Design offered by vendors. However, the selection of one solution or another by customers is usually conducted in an ad-hoc manner. Given the underlying environment that a customer might have and their limitations, there is no standard methodology that can help in the selection of the most appropriate solution. This paper therefore highlights the key characteristics of BPM solutions in the market to facilitate an understanding of the compatibility of a given solution with customer’s environments;hence, customers can then make informed decisions regarding their selections.展开更多
基金Financial support provided by the U.S. Department of Energy under DOE Grant No. DE-FE0002760
文摘This paper presents an improved understanding of coupled hydro-thermo-mechanical(HTM) hydraulic fracturing of quasi-brittle rock using the bonded particle model(BPM) within the discrete element method(DEM). BPM has been recently extended by the authors to account for coupled convective econductive heat flow and transport, and to enable full hydro-thermal fluidesolid coupled modeling.The application of the work is on enhanced geothermal systems(EGSs), and hydraulic fracturing of hot dry rock(HDR) is studied in terms of the impact of temperature difference between rock and a flowing fracturing fluid. Micro-mechanical investigation of temperature and fracturing fluid effects on hydraulic fracturing damage in rocks is presented. It was found that fracture is shorter with pronounced secondary microcracking along the main fracture for the case when the convectiveeconductive thermal heat exchange is considered. First, the convection heat exchange during low-viscosity fluid infiltration in permeable rock around the wellbore causes significant rock cooling, where a finger-like fluid infiltration was observed. Second, fluid infiltration inhibits pressure rise during pumping and delays fracture initiation and propagation. Additionally, thermal damage occurs in the whole area around the wellbore due to rock cooling and cold fluid infiltration. The size of a damaged area around the wellbore increases with decreasing fluid dynamic viscosity. Fluid and rock compressibility ratio was found to have significant effect on the fracture propagation velocity.
文摘Business Process Modeling (BPM) is a mechanism that separates all business aspects from the underlying technological and implementation features of a system. The aim is to capture an organization’s processes and achieve its business objectives. Currently, there are many solutions for Business Process Modeling and Design offered by vendors. However, the selection of one solution or another by customers is usually conducted in an ad-hoc manner. Given the underlying environment that a customer might have and their limitations, there is no standard methodology that can help in the selection of the most appropriate solution. This paper therefore highlights the key characteristics of BPM solutions in the market to facilitate an understanding of the compatibility of a given solution with customer’s environments;hence, customers can then make informed decisions regarding their selections.
