基于三维地质建模的四维地应力研究OA

Addressing issues such as lost circulation,overflow,and wellbore collapse encountered in marine sedimentary strata affected by diapirism,a reservoir structural model was established based on geological data from oil and gas fields.Combined with drilled well logging data,in-situ stress,formation pressure,and other data,a three-dimensional geomechanical model was constructed using Petrel software.Based on this,a four-dimensional in-situ stress model was further developed to analyze the variation of in-situ stress with the years of production.The research results indicate that:(1)the three-dimensional in-situ stress model has a high degree of consistency with single-well in-situ stress data,with a maximum error of 5.07%,demonstrating good accuracy;(2)after 15 years of oil and gas production,the maximum horizontal main in-situ stress decreased by 38.73～38.95 MPa,and the minimum horizontal main in-situ stress decreased by 43.58～43.8 MPa;(3)as production time increases,the formation pore pressure gradually decreases,and the limit collapse pressure differential of horizontal wells in the study area decreases accordingly.By 2026～2027,the limit pressure differential will equal the allocated production pressure differential,leading to wellbore collapse.Through four-dimensional in-situ stress field simulation technology,the study achieved prediction of the full-life production cycle of horizontal wellbore,providing an important basis for sand control design and safe production in areas affected by diapirism.