Leisi Ahsan, Shad Manaman Navid
Department of Mining Engineering, Sahand University of Technology, Tabriz, Iran.
Sci Rep. 2025 Apr 2;15(1):11276. doi: 10.1038/s41598-025-95796-z.
This paper presents a case study on the application of simultaneous inversion (SI) technique and well log analysis to accurately seismic-geomechanical characterization of Asmari formation in an Iranian oil field. To achieve this goal, a one-dimensional (1D) prediction of geomechanical properties such as Young's modulus (E), bulk modulus (K), shear modulus ([Formula: see text]), Poisson's ratio (PR), Vp/Vs ratio and brittleness (BRI) was first generated from the analyzing the well log data. In the next step, the spatial distribution of the geomechanical parameters in the reservoir area was predicted on the basis of the results of the simultaneous inversion. Lithological facies discrimination and fluid detection of the Asmari formation were performed using simultaneous inversion of pre-stack seismic data and conventional cross-plotting analysis of well data. To accomplish this objective, elastic and geomechanical parameters were cross-plotted against conventional petrophysical logs along with BRI, water saturation (Sw), gamma ray (GR), acoustic impedance (Zp), [Formula: see text], and lithology logs such as quartz and calcite volumes. As a result of this work, two reservoirs were identified in the Asmari formation: sandstone and carbonate. The carbonate reservoir consists predominantly of calcite and dolomite, with minimal shale content, while the sandstone reservoir is mainly composed of shale and contains less quartz. In addition, the carbonate section within the Asmari formation exhibits better reservoir quality due to lower water saturation and higher porosity compared to the sandstone zone. To determine the type of fluid in the Asmari formation of the studied oil field, LMR (lambda-mu-rho) scatterplots were employed in both well and seismic domains. The findings reveal that the sandstone reservoir in the Asmari formation is water-saturated, while the carbonate reservoir is oil-saturated. Furthermore, a gas cap is present at the top of the Asmari formation.
本文介绍了一个案例研究，该研究应用同步反演（SI）技术和测井分析，对伊朗某油田阿斯马里组进行精确的地震-地质力学特征描述。为实现这一目标，首先通过分析测井数据生成了一维（1D）地质力学性质预测，如杨氏模量（E）、体积模量（K）、剪切模量（[公式：见原文]）、泊松比（PR）、纵波速度与横波速度之比（Vp/Vs）和脆性（BRI）。下一步，基于同步反演结果预测了储层区域地质力学参数的空间分布。利用叠前地震数据的同步反演和测井数据的常规交会图分析，对阿斯马里组进行岩性相判别和流体检测。为实现这一目标，将弹性和地质力学参数与常规岩石物理测井以及BRI、含水饱和度（Sw）、伽马射线（GR）、声阻抗（Zp）、[公式：见原文]以及岩性测井（如石英和方解石体积）进行交会图分析。这项工作的结果是，在阿斯马里组中识别出两个储层：砂岩和碳酸盐岩。碳酸盐岩储层主要由方解石和白云石组成，页岩含量极少，而砂岩储层主要由页岩组成，石英含量较少。此外，与砂岩区相比，阿斯马里组内的碳酸盐岩段由于含水饱和度较低和孔隙度较高，表现出更好的储层质量。为确定所研究油田阿斯马里组中的流体类型，在测井和地震领域均采用了LMR（λ-μ-ρ）散点图。研究结果表明，阿斯马里组中的砂岩储层为水饱和，而碳酸盐岩储层为油饱和。此外，阿斯马里组顶部存在气顶。
