Research On Fault Sealability Of Fushuangda Area In Southern Songliao Basin

With the development of industry,oil exploitation has continued to increase.Many large oil and gas fields have entered the middle and late stages of exploration and development.However,many small and medium oil and gas fields have small reserves,complex fault conditions and difficult development,and the exploitation cost is higher than the actual profit,resulting in resources.The key technical difficulty is the migration and preservation of oil and gas in the formation.The proven reserves of deep tight gas in the southern Songliao Basin are 43.6 billion cubic meters,the proven rate is only 3.6%,and the remaining resource potential is large.In the Changling fault depression area,the main controlling factors of gas reservoirs are complicated and the trap implementation is difficult,resulting in a slower pace of exploration.In order to speed up the pre-exploration,reserves and production capacity construction of natural gas,it is urgent to solve the problems of optimization of favorable zones and utilization of trap benefits.Through the study of the oil and gas migration mechanism and the development process of fault sealing evaluation,consulted a large number of documents and data,it is believed that the stress state of underground faults is the main determinant of the opening or closing of the fault,and the opening or closing of the fault in turn determines the reservoir,whether the oil and gas are sealed or spilled along the fault plane and the channel in it,so as to determine the location of the favorable trap.Therefore,it is necessary to fully understand the causes,conditions,measurement methods and influencing factors of ground stress for studying the plugging properties of faults.The article elaborates on the basic concepts,causes,and influencing factors of in-situ stress.It classifies the measurement methods of in-situ stress from two aspects: direct measurement and indirect measurement.The principle and characteristics of each method are summarized and provided for actual calculation theoretical basis of in-situ stress.In this paper,through the processing and analysis of actual logging,seismic,and core data in the Fulongquan Gas Field,the relevant parameters needed for in-situ stress calculation are extracted,and combined with the data of the core triaxial stress experiment,the dynamic and static rock mechanics parameters are converted.Obtain the linear regression equation of the dynamic and static rock mechanics parameters in the study area,so as to realize the process of using logging curves and seismic data to obtain the in-situ stress in the relevant area;then establish the in-situ stress calculation model,analyze the advantages and disadvantages of each model and the scope of application,and The Huang's model is selected for example calculations,and the vertical and horizontal in-situ stress values of the Quan1,Quan2 and Yingcheng formations in the Fulongquan fault depression are calculated.Next,the fault plugging evaluation methods are classified,and the evaluation methods are qualitatively evaluated.The principles,advantages,disadvantages,and influencing factors of each evaluation method are explained in the two aspects of quantitative evaluation and quantitative evaluation.Finally,the method of calculating the pressure on the fault plane is used to calculate the gap between Wells Fu 13,Fu 14 and Fu 26 in the oil and gas enrichment area of the Fulongquan fault depression.The vertical sealing capacity of the mudstone layer is quantitatively evaluated.Using the calculation of the displacement pressure difference of the fault rock and the calculation of the mud content of the fault rock,the Fulongquan fault depression Fu13 yingcheng formation,Fu14 yingcheng formation,Fu26 shahezi are quantitatively evaluated.The lateral sealing capacity of 15 layers of sandstone reservoirs in the F26 Denglouku Formation and the Fu26 Denglouku Formation.The evaluation results are consistent with the high fluid pressure existing in the formation so far.The mudstone layer corresponding to the disconnection of the fault plane can be used as a cap layer to self-generate and self-storage below.The oil and gas produced by the oil and gas produced the role of sealing.Five layers with good sealing capacity were selected.Drilling and verification of oil and gas testing can be considered,and the scale and production of traps have been preliminarily judged,which provides a strong basis for the drilling and development of oil and gas fields.