Fracture control program

See High-Order Language (HOL) for additional related information. FRACTURE CONTROL PROGRAM... 

A systematic project activity to ensure that a space payload intended for flight has sufficient structural integrity as to present no critical or catastrophic hazard. This activity also ensures quality of performance in the structural area for any payload. Central to the program is fracture control analysis, which includes the concepts of fail-safe and safe-life, defined as follows ... 

However, it has been established that an intense control of certain variables may improve the execution of a hydraulic fracturing job and the success of a stimulation. Therefore an intense quality control is recommended [552,553]. Such a program includes monitoring the breaker performance at low temperatures and measuring the sensitivity of fracturing fluids to variations in crosslinker loading, temperature stabilizers, and other additives at higher temperatures. 

A computer-controlled rheology laboratory has been constructed to study and optimize fluids used in hydraulic fracturing applications. Instruments consist of both pressurized capillary viscometers and concentric cylinder rotational viscometers. Computer control, data acquisition and analysis are accomplished by two Hewlett Packard 1000 computers. Custom software provides menu-driven programs for Instrument control, data retrieval and data analysis. 

Table 1 Influence of visbreaking on the fracture toughness (NIS according to 179/leA) and stiffness measured in bending after ISO 178, bending. of non-nucleated and / -nucleated grades. CR means controlled rheology, PI polydispersity. AH (a) is the melt enthalpy of the a-phase (2nd scan), AH(fi) that of the -modification (2nd scan), Tc is the crystallization temperature determined by DSC with the scanning program + 10/ - 10/ + lOKmur1...

Abstract This contribution deals with the modeling of coupled thermal (T), hydraulic (H) and mechanical (M) processes in subsurface structures or barrier systems. We assume a system of three phases a deformable fractured porous medium fully or partially saturated with liquid and a gas which remains at atmospheric pressure. Consideration of the thermal flow problem leads to an extensively coupled problem consisting of an elliptic and parabolic-hyperbolic set of partial differential equations. The resulting initial boundary value problems are outlined. Their finite element representation and the required solving algorithms and control options for the coupled processes are implemented using object-oriented programming in the finite element code RockFlow/RockMech. 

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