Variation of Total Stresses During Field Operation Using Finite Element Technique, Zubair Oil Field.
祖拜尔油田主要面临地质力学问题，这可能导致大量的非生产时间。本研究旨在利用有限元法提出一个油藏模型和地质力学模型。我们利用测井数据、校准数据、钻井报告和泥浆报告等，使用Techlog 2015软件构建了每口井的一维模型（1D）。此外，我们使用Petrel 2017软件构建了三维地质力学模型，并使用CMG 2018版软件实施有限元法来预测10年内生产或注入过程中的总应力状态。
对于所有力学岩石性质的分析结果显示，在三维地质力学模型中，苏巴伊亚和阿尔哈马两个穹顶对于保持井的稳定性不足，特别是在塔努马层中。然而，米夏尔夫层显示出较高的稳定性，尽管有生产。此外，三维有限元模型显示，在生产过程中水平总应力减小，而在注入井中增加。这种变化会导致生产时有效水平应力增加，而注入井中减少。此外，在生产期间有效垂直应力增加，而注入井中减少。
根据这些结果，我们可以得出结论，生产可能会导致差异应力增加，从而导致岩石剪切破坏，而在注入情况下，孔隙压力增加，导致张拉破坏。
Abstract
The Zubair oil field is predominantly plagued by geomechanical issues, which can result in significant non-productive time. The aim of this study is to present a reservoir model and a geomechanical model utilizing the finite element method. The intriguing data consisting of logs, calibration data, drilling reports, and mud reports were utilized to construct one-dimensional models (1D) for each well using Techlog 2015 software. Furthermore, the 3D geomechanical model was built utilizing Petrel 2017 software, while the finite element technique was implemented using the CMG 2018 program to predict the total stress states during production or injection operations in the field over a span of 10 years.The analysis results of all mechanical rock properties in the 3D geomechanical model revealed that Shuaiba and Al-Hammar domes were insufficient for maintaining stable wells, particularly in the Tanuma formation. However, the Mishrif formation displayed higher stability despite production. Furthermore, the 3D finite element model exhibited that the total horizontal stress decreased during production and increased in injection wells. This variation would result in an increase in the effective horizontal stress during production and a decrease in injection wells. Moreover, the effective vertical stress increased during production and decreased during injection wells. Based on these outcomes, it can be concluded that production could trigger an increase in the differential stress leading to rock shear failure, whereas in injection cases, pore pressure increased, and this caused tensile failure.
