Development of one-dimensional and three-dimensional geomechanical modeling of reservoir rock in oil fields

Hossein Shouri, Khalil Shahbazi, Mohammad Abdideh

The geomechanical model as a solid foundation can be the basis of a major part of upstream oil studies and a new low-risk drilling approach, along with a high efficiency factor and reducing damage to reservoirs. The use of stress directions in oil fields is essential for solving engineering and geological problems. The direction and magnitude of the larger horizontal stress are effective in creating and directing tensile fractures in the wellbore. Today, in the oil industry, when forecasting programs for drilling operations are written, attention should be paid to rock mechanics issues in the category of wellbore stability and the selection of appropriate mud weight, because a lack of attention will cost money and time. In order to avoid these problems, rock mechanic forecasts must be used. In this research, it has been tried to first build a one- and three-dimensional geomechanical model, then discuss and investigate the stability of the wellbore. Geo log and Excel software have been used to interpret drilling logs and extract modules, as well as to build a one-dimensional geomechanical model. Petrophysical values, dynamic modules, and pore pressure have been obtained by interpreting the caliper, sonic, density, gamma ray, and DSI logs available for four wells located in the Maroun field. Using experimental relationships, the values of petrophysical and rock mechanical parameters such as porosity, vertical stress, horizontal stress, pore pressure, static elasticity moduli, Poisson's coefficient, stickiness, and internal friction angle have been calculated. The output of one-dimensional models in Geo log and Excel software is used as the input data for Petrel software to build a three-dimensional static model. In this software, the geostatistical methods of successive Gaussian simulation and Gaussian random function simulation were used to build a 3-D model. To calibrate the results obtained from the analysis of the stability and collapse of the 3D model wall, the caliper log was used, which has a good match with the 3-D model. By comparing the results of the wall collapse investigation using calipers with the results of the geo mechanical model built for well stability analysis, it can be seen that this model responds well to 3D. Analysis of well stability and whether it can be matched It is acceptable. In the model, it shows relatively deep collapse in the upper part and scattered collapse in the middle part.