Study On Ground Subsidence Regularity For Typical Oil Producing Region Based On SBAS-InSAR

With the rapid development of China ' s economy and the continuous improvement of urbanization,the problems of ground subsidence and land resource damage dominated by human activities have become increasingly prominent.Large-scale ground subsidence has become an important bottleneck restricting local economic development.Songnen Plain is located in the central part of the Songliao Basin in Northeast China.It is the largest part of the Northeast Plain and deposited about 600 m thick lacustrine oil-bearing strata in the Early Cretaceous.In addition to the large-scale exploitation of groundwater in Songnen Plain,the large-scale exploitation of oil and gas mainly in Daqing has led to a series of problems such as large-scale surface subsidence,land resources and ecological environment damage,affecting the sustainable development of the region.However,compared with the study of ground subsidence caused by groundwater exploitation,the domestic research on ground subsidence caused by oil and gas exploitation is extremely weak,and even the regularity of land subsidence in oil and gas exploitation area is not clear.It is urgent to carry out the research on land subsidence in oil and gas exploitation area.The traditional ground subsidence monitoring methods(such as leveling)can obtain sparse point subsidence data,but the workload of measurement is large and the cycle is long.Especially for large-scale ground subsidence monitoring,it is difficult to obtain the overall deformation in the surface dimension.As a new method of ground micro-deformation monitoring,InSAR can obtain large-scale and high-precision ground change information,and has prominent technical advantages such as all-time,all-weather and high deformation sensitivity.In this paper,the ground subsidence monitoring and driving factor analysis of Songyuan oil production area in western Jilin of Songnen Plain are carried out by means of time-series InSAR technology and target monitoring algorithm based on remote sensing images.The main research contents are as follows :(1)InSAR-based land subsidence monitoring data processing,verification and accuracy assessment.Using Sentinel-1 radar data as the data source,the SBAS-InSAR method was used for data processing to obtain the ground settlement results of the study area,and the settlement results based on the ALOS-2 radar data source were crossvalidated and compared with the leveling results to ensure that Reliability of InSAR monitoring results and evaluation of measurement accuracy.(2)Analysis of the characteristics of the temporal and spatial evolution of land subsidence and the regularity of subsidence.Based on the InSAR settlement measurement results,the temporal and spatial evolution characteristics of settlement are analyzed.In addition,non-linear theories such as gray system theory,time series analysis and BP neural network are used to establish the overall land subsidence prediction model of the study area and evaluate the prediction accuracy of different models.After comparison,the prediction accuracy of the time series analysis method is slightly better than that of the gray system analysis method and the BP neural network method.(3)Analysis of driving factors of land subsidence.Use the trained YOLO v3 target detection algorithm to detect the location of oil production wells in the study area,analyze the distance effect of oil production on land subsidence,and quantitatively evaluate the impact of cumulative oil and gas production on land subsidence by establishing a relationship model between oil and gas production and subsidence.At the same time,it discusses the driving factors and influencing characteristics of land subsidence in combination with meteorology,groundwater,earthquakes,etc.Through analysis,it is concluded that oil and gas exploitation has a distance effect on the surface subsidence,and there is a significant linear negative correlation between land subsidence and cumulative oil and gas exploitation.In addition,the amount of ground subsidence near the water area is relatively large,and the ground subsidence is obviously negatively correlated with the groundwater level and accumulated precipitation,while the relationship between earthquakes and air temperature and ground subsidence is not obvious.Through the analysis of surface subsidence and its regularity in Songyuan oil production area,it can provide scientific basis for the prevention and control of land subsidence geological disasters and environmental protection in typical oil and gas exploitation areas.It also provides data reference for the sustainable development of ecological environment in similar energy exploitation areas,and has practical significance for understanding the regularity of land subsidence in oil production areas and accelerating the revitalization of the old industrial base in Northeast China.