Drilling Difficulties and Optimization Countermeasures of Multilayer Gas Reservoirs in Unconsolidated Sandstone
Sebei gas field is a typical unconsolidated sandstone gas reservoir with many longitudinal gas layers,strong loose heterogeneity and sensitive minerals.A large number of gas reservoir geological,dynamic monitoring and drilling data were used to analyze the existing problems and technical difficulties in drilling construction and carry out optimization countermeasures.The results show that:1)the porosity of the reservoir,multiple thin interbeds,high salinity and the disturbance of the longitudinal pressure system in the late stage of development are the main factors affecting the construction of the optimal drilling;2)aiming at the problems of large well control risk and difficult well structure determination in drilling construction,the well structure of different gas reservoirs,different depths and different positions is determined through optimization study;3)in view of the prominent leakage problem,the suitable MEG drilling fluid system with low damage and effective inhibition of clay expansion was developed;4)to solve the problem that cementing quality is difficult to guarantee,measures such as nano-low density cement slurry,process improvement and fine construction are adopted.It is concluded that the application effect of the optimization technical countermeasure is obvious,the difficulty of drilling technology is solved,and the fast and safe drilling of unconsolidated sandstone multi-layer gas reservoir is realized.
loose sandstone gas reservoirwell body structurecementing qualitywell leakagelow density cement slurry
NETL
NSTL
万方数据
维普
