Casing Damage Causes And Design Method Of Unconventional Reservoir Wells

With the development of the world’s oil and gas industry and the national strategy of energy demand increasing,since the shale gas revolution began,the fracturing process to vertical wells and horizontal wells has become a key factor to develop shale gas,and fracturing as one of the key production technology has been widely used.For a well fracturing method is appropriate or not,can not only influence economic benefits,at the same time can also reduce the casing damage,reduce cost and improve efficiency which plays a very important role,it also can reduce the possibility of accident and really make sure that the benefit of oil and gas well production is safe and effective.This article is about the investigation and research at home and abroad research status of the principle of the casing damage,using numerical simulation method to simulate casing deformation under different conditions,using CAE software ABAQUS to establish a two-dimensional plane strain model of casing,cement and ground After Mises strain and stress distribution is simulated,it will generate a series of figures more intuitively.Then we use the software to simulate surrounding rock elastic modulus decrease respectively,different diameter thickness with different grade of steel,cement part missing or all missing,the elastic modulus,poisson ratio and lower strength,the maximum and minimum horizontal principal stress difference,and then one southwest certain well casing deformation model is established,and carries on the simulation analysis,according to the mathematical model results,which indicates that the main reason affecting casing deformation.Accounting to the analysis results of the finite element simulation software,at the same time,and the fracturing dobby logging curve comparison test results,a preliminary conclusion of casing deformation can be included: during the process of fracturing,casing cement ring,surrounding rock performance degradation,quality problems,high ground stress and high stress can make a series of consequences.Finally the design method of the deformation of casing damage during the process of fracturing is suggested.This article research results can be referenced for the process of shale wells fracturing so that casing deformation damage prevention can be controlled in a certain extent.