For field development and drilling decisions, production assets and reservoir engineers require dynamic reservoir properties, such as saturation and pressure changes of a reservoir from the pre-production virgin state. To date, geophysicists have produced time-lapse (4D) seismic attributes (mostly on stacked seismic data) rather than dynamic parameters directly. In this paper, we present a new method to estimate saturation and pressure properties from time-lapse seismic data to provide to reservoir engineers. This new three-step method is demonstrated over the Edvard Grieg field in the North Sea. We can realize this method thanks to advanced seismic multi-component acquisition via PP and PS seismic data and processing that allows accurate estimation of amplitude-variation-with-offset parameters P- and S-impedances. With time-lapse P- and S-impedances optimally resolved, we estimate a stable set of axes identifying water saturation increase (water replacing oil), gas saturation increase (gas injection or gas out of solution), pressure increase (at injectors) and pressure decrease (at producers). Once these axes are obtained, we convert every 4D P- and S-impedance data points into 4D pseudo-saturation and pseudo-pressure using a transformation of coordinates. We next use the rock physics relationships of this field to show that a linear relationship can be used to map any 4D change in the field from impedances to saturations and pressures. Key locations in the field with largest saturation and pressure changes are used to find calibration values at these extreme points. Next, from the pseudo-seismic 4D data, a linear mapping is used to calculate actual reservoir property changes (fractions for saturation and bars for pressure). This allows us to obtain fieldwide dynamic values for water and gas saturations and injection and production related pressure changes. The results are shown, and dynamic changes are interpreted on the Edvard Grieg field data.

中文翻译：

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4D PP 和 PS 地震数据的定量压力和饱和度工程值

对于油田开发和钻井决策，生产资产和油藏工程师需要动态油藏特性，例如油藏相对于生产前原始状态的饱和度和压力变化。迄今为止，地球物理学家已经生成了时移 (4D) 地震属性（主要是基于叠加地震数据），而不是直接生成动态参数。在本文中，我们提出了一种根据时移地震数据估计饱和度和压力特性的新方法，以提供给油藏工程师。这种新的三步法在北海的爱德华·格里格油田得到了演示。我们可以实现这种方法，这要归功于通过 PP 和 PS 地震数据进行先进的地震多分量采集和处理，可以准确估计振幅随偏移参数 P 和 S 阻抗的变化。通过对时移 P 阻抗和 S 阻抗进行最佳解析，我们估计了一组稳定的轴，用于识别水饱和度增加（水替代油）、气体饱和度增加（气体注入或气体脱离溶液）、压力增加（在注入器处）和压力降低（生产商）。获得这些轴后，我们使用坐标变换将每个 4D P 和 S 阻抗数据点转换为 4D 伪饱和度和伪压力。接下来，我们使用该场的岩石物理关系来表明线性关系可用于映射场中从阻抗到饱和度和压力的任何 4D 变化。现场饱和度和压力变化最大的关键位置用于查找这些极值点的校准值。接下来，根据伪地震 4D 数据，使用线性映射来计算实际储层特性变化（饱和度分数和压力条）。这使我们能够获得全油田水和天然气饱和度以及与注入和生产相关的压力变化的动态值。显示结果，并根据爱德华·格里格现场数据解释动态变化。