| With the development of oil exploration and development process,the demands for exploration and development of marginal oilfields and unconventional resources has increased continuously.Such as shale gas,coal-bed methane’s proportion in energy structure gradually increased.However,there still exists the technical troubles within borehole stability and hydraulic fracturing in the process of drilling and production,and study of geological mechanical model which is closely related to the troubles has becoming more and more urgent,and in the process of established the model key parameters computation is particularly important,including wall-bore wall stress analysis,rock mechanical parameters,formation collapse and fracture pressure,etc.They play a technical role for guiding the drilling and fracturing.In this paper,the main content is put forward a method by combination of geological and engineering to establish the geological mechanics model,and focus research on the key parameters computation in the process of model,compensation formula fitting of the shear wave data,rock tri-axial experimental data analysis and the stress and strain formula fitting under arbitrary confining pressure condition,and mechanical parameters extraction along the borehole trajectory.After that the geological mechanical model is established and key parameter is calculated by application of XX blocks’ data,which realized the mechanical parameters profile extraction and stability analysis along the wellbore trajectory.The study is divided into the following steps: firstly,the differences and relations between conventional geological model and geological mechanics model are given,and specific parameter source required to the process of establishing geological mechanics model is determined.Secondly,shear wave data prediction formula is obtained by fitting out under the different strata lithology,multi-parameter to solve the problem of lack of shear wave data in log data.In addition,using the finite element software to simulate rock tri-axial stress and strain and fitting relationship is obtained under arbitrary confining pressure of rock,the fitting formula is verified by comparison with the experimental data analysis in the range of allowable error of the consistency of the data.Finally,based on the key parameters calculation,the thought,method and process of establishing geological mechanics model isput forward,and with XX blocks a particular area of geological mechanics model is set up,complete geological mechanics parameter is extracted along the borehole trajectory profile.geological mechanical model establishment of calculation of key parameters in the process and along the well trajectory profile extraction,put forward corresponding train of thought and method for,focusing on the completion of the model establish calculation of key parameters and shear wave data compensation formula fitting,rock triaxial experiment data analysis and arbitrary confining pressure should be fitting the stress-strain formula,and along the extraction of mechanical parameters of wellbore trajectory.Finally,the key parameters of the XX block are calculated and the model is established,and the extraction and stability analysis of the mechanical parameters of the trajectory along the well trajectory is realized.First of all,through the investigation and study of the process of the establishment of the geological mechanics model in the domestic and foreign drilling process,the calculation method of the corresponding model parameters is analyzed.On this basis,combined with geologic and engineering parameters calculation method,and expounds the geological mechanical model to establish the differences and connections between the sources of information in the process and the conventional geologic model and geological mechanics model is proposed.Secondly,in view of the lack of logging data,the prediction formula of shear wave data under different formation lithology and multi parameter is fitted.In addition,based on the finite element software,the three axis simulation of rock is obtained,and the fitting relationship between the stress and strain of rock under arbitrary confining pressure is obtained.Finally,based on the key parameters calculation based on the proposed the establishment of geological mechanical model of train of thought,method,process,and combined with the MEM of specific XX block region is established and completed along the wellbore trajectory geological mechanics parameter of the profile extraction.Through the research of the contents,fitting formula of shear wave compensation and tri-axial stress-strain is obtained in the process of establishing mechanical earth model,a method is put forward which is extracted the mechanical parameters along the borehole trajectory,fo r further forcast warning and correction while drilling provides the theoretical basis. |
