Ma Pingshan, Lin Chengyan, Liu Haocheng, Li Shaohua, Wang Shun
School of Geosciences, China University of Petroleum (East China), Qingdao, 266580, China.
Reservoir Geology Key Laboratory of Shandong Province (East China), Qingdao, 266580, China.
Sci Rep. 2025 May 30;15(1):19004. doi: 10.1038/s41598-025-04185-z.
The incompleteness of data and the variability in research methodologies can lead to significant uncertainties in reservoir modeling predictions. Effectively reducing and assessing these uncertainties are central issues in reservoir modeling studies. This research takes the ultra-low permeability and ultra-low porosity conglomeratic sandstone oil reservoir in the Yong 935-936 block of the Dongying Depression as a case study to conduct a survey on uncertainty modeling and evaluating. Considering the presence of multiple sediment sources in the study area, a variogram model with local variable azimuth angles is designed to address the discontinuity of sand bodies at the partition boundaries during modeling. Geological insights are used to delineate the boundaries of fan bodies, and statistical analysis of the proportions of sandstone and mudstone under different effective reservoir property limits within these fan bodies provides conditional data to reduce uncertainties in the modeling process. A full-factor experiment is conducted to perform a sensitivity analysis on parameters influencing reserves calculations, clarifying the significance of various influencing factors, such as fan body boundaries, effective reservoir property thresholds, and variogram range. A multivariate regression model between reserves calculation and significant influencing factors is constructed through response surface experiments. Finally, combining the Monte Carlo random simulation method, the distribution of cumulative probability reserves is obtained, and the 3P reserves of the study area are predicted to test the effectiveness of the multivariate regression model.
数据的不完整性和研究方法的变异性可能导致油藏建模预测中出现重大不确定性。有效降低和评估这些不确定性是油藏建模研究的核心问题。本研究以东营凹陷永935 - 936区块的超低渗透、超低孔隙度砾岩砂岩油藏为例，开展不确定性建模与评价研究。考虑到研究区存在多个物源，设计了一种具有局部可变方位角的变差函数模型，以解决建模过程中砂体在分区边界处的不连续性问题。利用地质认识圈定扇体边界，并对这些扇体内不同有效储层物性界限下砂岩和泥岩的比例进行统计分析，提供条件数据以降低建模过程中的不确定性。进行全因子实验，对影响储量计算的参数进行敏感性分析，明确扇体边界、有效储层物性阈值、变差函数范围等各种影响因素的重要性。通过响应面实验构建储量计算与重要影响因素之间的多元回归模型。最后，结合蒙特卡罗随机模拟方法，得到累积概率储量分布，预测研究区的3P储量，以检验多元回归模型的有效性。
