Assessment of uncertainty in 2D and 3D geostatistical models for use in steam assisted gravity drainage prediction

蒸汽辅助重力排水(SAGD)用于从阿萨巴斯卡油砂中生产碳氢化合物。地统计学方法被用来对油砂的性质进行建模，然后用来预测石油产量、蒸汽使用量和能源消耗。属性包括孔隙度、沥青含量、渗透率和岩石类型。对这些属性进行建模涉及估计或模拟网格上矿床中每个未采样位置的未知量，并且通常具有不确定性。这些估计使用了所有可用的信息，如地球物理测量、油井数据、地震、地球化学、地质力学等。拟议工作的总体目标是通过正确考虑所有建模方面的不确定性，准确预测SAGD环境中的不确定性。在实施当前的最佳做法不确定度评估方法时，使用2D或3D模型计算的不确定度之间存在差异。通常，2D模型用于计算全球原地石油资源/储量，而3D模型用于通过流动模拟进行石油产量预测。该项目的目标是(1)协调2D和3D不确定性模型之间的差异(2)提出方法以有效地一致地估计2D或3D模型的全球不确定性(包括趋势不确定性)和(3)调查正确建模不确定性对SAGD性能预测、井布置以及多个SAGD焊盘的经济/环境考虑的影响。

Steam assisted gravity drainage (SAGD) is used to produce hydrocarbons from the Athabasca Oil Sands. Geostatistical methods are used to model properties of the oil sands that are then used to forecast oil production, steam usage and energy consumption. Properties include porosity, bitumen content, permeability and rock type. Modeling these properties involves estimating or simulating unknown quantities at every unsampled location in the deposit on a grid and usually with uncertainty. These estimates are made using all available information such as geophysical surveys, well data, seismic, geochemical, geomechanical, etc. The overall goal of the proposed work is to accurately predict uncertainty in a SAGD environment by correctly accounting for uncertainty in all modeling aspects. When implementing current best practice uncertainty assessment methodologies, there is a discrepancy between uncertainty calculated using 2D or 3D models. Typically 2D models are used to calculate oil in place global resources/reserves while 3D models are used for oil production prediction with flow simulation. The goals of this project are to (1) reconcile differences between 2D and 3D uncertainty models (2) propose methodologies to effectively estimate global uncertainty consistently for 2D or 3D models including trend uncertainty and (3) investigate the impact of correctly modeling uncertainty on SAGD performance prediction, well placement and economic/environmental considerations for multiple SAGD pads.