Overpressure

About: Overpressure is a research topic. Over the lifetime, 3236 publications have been published within this topic receiving 34648 citations.

Overpressure at the Macondo Well and its impact on the Deepwater Horizon blowout

Abstract: At the Macondo well, the overpressure (fluid pressure greater than hydrostatic) in the main reservoir is nearly identical to that within a stratigraphically equivalent sandstone at the Galapagos development 21 miles (34 km) to the south; we interpret that the reservoirs share a permeable, laterally extensive, and hydraulically connected aquifer. At Macondo, pore pressure approximately parallels the overburden stress to a depth of 17,640 ft (5,377 m) subsea and thereafter decreases abruptly by 1,200 psi (8.3 MPa) over 370 ft (113 m) as the main sandstone reservoir is approached. In contrast, at Galapagos, pore pressure increases with the overburden stress for the entire well depth. The pore pressure regression at Macondo was responsible for a reduction in the least principal stress. This, in combination with the extreme pore pressures within overlying strata, drastically narrowed the range of safe operational borehole pressures. These geologic phenomena produced challenging conditions for drilling, prevented successful temporary abandonment of the well, and contributed to the well’s failure.

Uses of pressure and temperature data in exploration and new developments in overpressure detection

Abstract: Pressure and temperature data from wireline logs and seismic-velocity analysis can be used in deep overpressures to aid in prospect evaluation. Properly interpreted seismic-velocity analysis in deep water can yield maturation and migration information. Use of a modified approach to the d exponent and use of measurement-while-drilling (MWD) data have proved successful in deepwater pressure detection.

Effects of structural congestion and surrounding obstacles on the overpressure loads in explosions: experiment and CFD simulations

Abstract: An experimental and numerical study was undertaken to identify the characteristics of overpressure loads in offshore platform models subject to hydrocarbon explosions, with a focus on the structural congestion and surrounding obstacles. A large-scale (one-half) test model of a FLNG (liquefied natural gas floating production storage and offloading unit) topside structure was used for the experiment. Computational fluid dynamics (CFD) were used to calculate the overpressure loads in explosions with varying degrees of structural congestion. The overpressure loads tended to be more significant with the increase in structural congestion because the ventilation of exploded gas was retarded due to the obstacles presented by congested structural elements. Also, the overpressure loads with the surrounding structures are much larger than those without them. Details about the test database are documented to provide a useful reference for other researchers to validate numerical and theoretical methods.

Sound attenuation with foam

Abstract: Method for reducing the peak overpressure of an explosion by disposing in the path of the explosion a barrier of an aqueous foam containing dispersion particulates predominately smaller than 200 mesh.