To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells...To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells were selected to carry out the running test of sand control string with pre-packed screen.Meanwhile,the running simulation was performed by using the Landmark software.The results show that the sand control packer and screen can be run smoothly in the wellbore with a dogleg angle of more than 20°/30 m and keep the structure stable.Additionally,the comprehensive friction coefficient is 0.4,under which and the simulation shows that the sand control string for hydrate exploitation can be run smoothly.These findings have important guiding significance for running the completion sand control string in natural gas hydrate exploitation.展开更多
In Well MJ4,Tarim Basin,the testing tubing string is 6617 m long and the bottom-hole pressure during the testing is 101.63 MPa.During the completion job,plastic deformation occurs in the tubing string,so it is very ne...In Well MJ4,Tarim Basin,the testing tubing string is 6617 m long and the bottom-hole pressure during the testing is 101.63 MPa.During the completion job,plastic deformation occurs in the tubing string,so it is very necessary to figure out at which stage of the completion job plastic deformation occurs on earth.For this reason,the three-dimension finite element analysis method was used to perform numerical calculations for the deformation of tubing string and the distribution of axial stress based on three typical load conditions(setting load,fracturing load,and well testing load of Well MJ4);a process for calculating the mechanical behavior of a completion and testing tubing string containing an expansion joint was then developed.The study content mainly includes:(1)A criterion was developed to determine the extension and closure status of the expansion joint in the tubing string;corresponding calculation mechanism and formulae were provided;and the extensioneclosure status of the expansion joint in the tubing string for Well MJ4 was calculated.(2)A method was developed for analyzing and calculating the additional pressure difference load in the packer annulus caused by poor engagement of the hydraulic anchor;the impact of the additional pressure difference load on the deformation behavior of the tubing string was simulated;and the significant impact of the additional pressure difference load on the plastic buckling deformation was figured out.(3)The limit of lateral buckling deformation in a calculation model was introduced,and so the impact of collar rigidity on the buckling deformation was indirectly considered;the deformation under the joint action of all loads of the tubing string was calculated,and the numerical result was the same as the observed deformation.The study results show that the plastic deformation of the tubing string for Well MJ4 occurs at the fracturing stage and the major causes are hydraulic pressure loads and gravity loads in different forms.The conclusion shows that the mechanical calculation model of the testing tubing containing the expansion joint can be used as an important theoretical tool and analysis approach in optimizing operations and designing the tubing string structure.展开更多
基金supported jointly by one of the major projects of Basic and Applied Basic Research in Guangdong Province“Key Basic Theory Research for Natural Gas Hydrate Trial Production in Shenhu Pilot Test Area”(2020B0301030003)the project from Southern Marine Science&Engineering Guangdong Laboratory Guangzhou City“Research on New Closed Circulation Drilling Technology without Riser”(GML2019ZD0501)the special project for hydrate from China Geological Survey“Trial Production Implementation for Natural Gas Hydrate in Shenhu Pilot Test Area”(DD20190226)。
文摘To meet the requirements of marine natural gas hydrate exploitation,it is necessary to improve the penetration of completion sand control string in the large curvature borehole.In this study,large curvature test wells were selected to carry out the running test of sand control string with pre-packed screen.Meanwhile,the running simulation was performed by using the Landmark software.The results show that the sand control packer and screen can be run smoothly in the wellbore with a dogleg angle of more than 20°/30 m and keep the structure stable.Additionally,the comprehensive friction coefficient is 0.4,under which and the simulation shows that the sand control string for hydrate exploitation can be run smoothly.These findings have important guiding significance for running the completion sand control string in natural gas hydrate exploitation.
基金supported by the National Major Science and Technology Project“Optimal and fast ultra-deep HTHP well construction and gas recovery technologies”(No.:2016ZX05051003)the National Natural Science Foundation of China(General Program)“Theoretical and experimental studies on key mechanical aspects in unconventional gas recovery”(No.:11272216).
文摘In Well MJ4,Tarim Basin,the testing tubing string is 6617 m long and the bottom-hole pressure during the testing is 101.63 MPa.During the completion job,plastic deformation occurs in the tubing string,so it is very necessary to figure out at which stage of the completion job plastic deformation occurs on earth.For this reason,the three-dimension finite element analysis method was used to perform numerical calculations for the deformation of tubing string and the distribution of axial stress based on three typical load conditions(setting load,fracturing load,and well testing load of Well MJ4);a process for calculating the mechanical behavior of a completion and testing tubing string containing an expansion joint was then developed.The study content mainly includes:(1)A criterion was developed to determine the extension and closure status of the expansion joint in the tubing string;corresponding calculation mechanism and formulae were provided;and the extensioneclosure status of the expansion joint in the tubing string for Well MJ4 was calculated.(2)A method was developed for analyzing and calculating the additional pressure difference load in the packer annulus caused by poor engagement of the hydraulic anchor;the impact of the additional pressure difference load on the deformation behavior of the tubing string was simulated;and the significant impact of the additional pressure difference load on the plastic buckling deformation was figured out.(3)The limit of lateral buckling deformation in a calculation model was introduced,and so the impact of collar rigidity on the buckling deformation was indirectly considered;the deformation under the joint action of all loads of the tubing string was calculated,and the numerical result was the same as the observed deformation.The study results show that the plastic deformation of the tubing string for Well MJ4 occurs at the fracturing stage and the major causes are hydraulic pressure loads and gravity loads in different forms.The conclusion shows that the mechanical calculation model of the testing tubing containing the expansion joint can be used as an important theoretical tool and analysis approach in optimizing operations and designing the tubing string structure.
