The Studies On Closing Mechanisms Of Fracture In Compact Sandstone Gas Reservoir

The compact sandstone gas reservoir play an important part in gas exploitation.Fracture is the general characteristic in the compact sandstone gas reservoir.It is valueness while no fracture.Success or failure to exploit the compact sandstone gas reservoir is mainly decided to the level of knowing and utilizing the natural fracture system.In the process of planning well network,preserving reservoir,designing route,waterflood development,fracture system all take an important part.So,fracture is the key to exploit the compact sandstone.In order to obtain a finding that is mezningful to guide in the spot,the closing mechanism of micro-fracture in compact sandstone gas reservoir in the dissertation.Based on present researches,by means of modern measurement and analysis techniques,systemic laboratory experiments,field investigations and through theory researches were conducted.And following are the major points and achievements presented in this dissertation:â‘ The micro-convexity on fracture plane was studied.Analyzing and comparing the static attribute and dynamic variation of natural fracture with the artificial,untreated fracture,artificial and scabbled fracture as well,making out the criteria that artificial and scabbled fracture simulate natural fracture.â‘¡We take the effect of all the three primary stresses and stress invariant into account in the Lade-dbl yield criterion,which can preferably reflect all the yield and destruction characteristic of the rock material.â‘¢The experiment of the fracture inner space stractual evolution indicates that it is easy macroscopic fracture closing into microscopic fracture,while it is difficult microscopic fracture closing into more microscopic fracture.The reason is that there will be additional resistance when the micro convexity is pressed to keep on distortion.â‘£The K-P relation we get directly through measuring permeability is the same formly as the one we get through taking into account the effect of the width and roughness of the fracture,and it is accordant with the conclusion we study the fracture closing mechanism forenamed,which proves that it is feasible to estimate the stress...