River Formation In Western Sichuan Technology Research Borehole Stability In The Southern Region To Be Home

Xujiahe formation of southwest regin has complex geological conditions.The lithology is mainly shale, which is easy to be hydrate expansion.Coupled with natural fractures, may causing collapse and lost circulation.And the unreasonable density of drilling fluid may cause borehole instability, hole enlargement, necking,thus resulting drilling downhole card.When these underground complex happening, will cause drilling speed lower in the region, seriously affecting the drilling progress of the project, which restricts the entire Xujiahe gas exploration and development evaluation. So it is necessary for the region Xujiahe formations to analysis wellbore stability situation appear in drilling and completion.In this paper,according to the Xujiahe formation of southwestern Sichuan in drilling and completion of the complex situation underground, through the drilling data, indoor experimental research, as well as in-depth theoretical study and mathematical model, and start wiht the basic physical properties of the rocks,needs some research of wellbore stability studies on Xujiahe Formation. And following are the major points and achievements presented in this dissertation:(1) The drilling data of Lianhuashan and Zhangjiaping structure have been constructed to analysis the feature and laws of borehole instability.(2) Explain the rock mechanics parameters and stress through laboratory experiments.(3) Establish the mechanical model of wellbore stability, and have been carried out on the well drilled.(4) Evaluate on drilling fluid system and conduct researchs on the factors influencing the stability and regularity borehole.The papers analysis the borehole collapse situation during drilling in the region Xujiahe formation,will provide technical support in reducing the happening of borehole instability,increasing drlling speed,and safe operation.