Mechanical Modeling and Analysis of Stability Deterioration of Production Well During Marine Hydrate Depressurization Production  

作　　者：SUN Huan-zhao CHANG Yuan-jiang SUN Bao-jiang WANG Kang CHEN Guo-ming LI Hao DAI Yong-guo 

机构地区：[1]Centre for Offshore Engineering and Safety Technology,China University of Petroleum(East China),Qingdao 266580,China [2]School of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,China [3]Jiangsu Shuguang Oil Tools Co.,Ltd,Taizhou 225532,China

出　　处：《China Ocean Engineering》2024年第2期338-351,共14页中国海洋工程（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Grant No.51890914)。

摘　　要：Different from oil and gas production,hydrate reservoirs are shallow and unconsolidated,whose mechanical properties deteriorate with hydrate decomposition.Therefore,the formations will undergo significant subsidence during depressurization,which will destroy the original force state of the production well.However,existing research on the stability of oil and gas production wells assumes the formation to be stable,and lacks consideration of the force exerted on the hydrate production well by formation subsidence caused by hydrate decomposition during production.To fill this gap,this paper proposes an analytical method for the dynamic evolution of the stability of hydrate production well considering the effects of hydrate decomposition.Based on the mechanical model of the production well,the basis for stability analysis has been proposed.A multi-field coupling model of the force state of the production well considering the effect of hydrate decomposition and formation subsidence is established,and a solver is developed.The analytical approach is verified by its good agreement with the results from the numerical method.A case study found that the decomposition of hydrate will increase the pulling-down force and reduce the supporting force,which is the main reason for the stability deterioration.The higher the initial hydrate saturation,the larger the reservoir thickness,and the lower the production pressure,the worse the stability or even instability.This work can provide a theoretical reference for the stability maintaining of the production well.

关 键 词：natural gas hydrate production well depressurization production formation deformation stability deterioration 

分 类 号：TE53[石油与天然气工程—油气田开发工程]