Uncertainty quantification of overpressure buildup through inverse modeling of compaction processes in sedimentary basins | Quantification de l’incertitude sur l’accumulation de surpression par modélisation inverse des processus de compaction dans des bassins sédimentaires Incertidumbre en la cuantificación de la acumulación de la sobrepresión a través del modelado inverso de procesos de compactación en cuencas sedimentarias 通过沉积盆地中压实过程的反演模拟对超压逐步积累进行不确定性量化 Quantificação de incertezas do acúmulo de sobrepressão utilizando modelagem inversa dos processos de compactação em bacias sedimentares
2017
Colombo, Ivo | Porta, Giovanni M. | Ruffo, Paolo | Guadagnini, Alberto
This study illustrates a procedure conducive to a preliminary risk analysis of overpressure development in sedimentary basins characterized by alternating depositional events of sandstone and shale layers. The approach rests on two key elements: (1) forward modeling of fluid flow and compaction, and (2) application of a model-complexity reduction technique based on a generalized polynomial chaos expansion (gPCE). The forward model considers a one-dimensional vertical compaction processes. The gPCE model is then used in an inverse modeling context to obtain efficient model parameter estimation and uncertainty quantification. The methodology is applied to two field settings considered in previous literature works, i.e. the Venture Field (Scotian Shelf, Canada) and the Navarin Basin (Bering Sea, Alaska, USA), relying on available porosity and pressure information for model calibration. It is found that the best result is obtained when porosity and pressure data are considered jointly in the model calibration procedure. Uncertainty propagation from unknown input parameters to model outputs, such as pore pressure vertical distribution, is investigated and quantified. This modeling strategy enables one to quantify the relative importance of key phenomena governing the feedback between sediment compaction and fluid flow processes and driving the buildup of fluid overpressure in stratified sedimentary basins characterized by the presence of low-permeability layers. The results here illustrated (1) allow for diagnosis of the critical role played by the parameters of quantitative formulations linking porosity and permeability in compacted shales and (2) provide an explicit and detailed quantification of the effects of their uncertainty in field settings.
显示更多 [+] 显示较少 [-]