Calculation analysis of sustained casing pressure in gas wells  

作　　者：Zhu Hongjun Lin Yuanhua Zeng Dezhi Zhang Deping Wang Feng 

机构地区：[1]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China [2]Jilin Field Company,PetroChina,Songyuan,Jilin 138000,China

出　　处：《Petroleum Science》2012年第1期66-74,共9页石油科学（英文版）

基　　金：co-financed by the China National Natural Science Foundation and Shanghai Baosteel Group Corporation (No. 51074135);Program for New Century Excellent Talents in University (No. NCET-08-0907);Jilin Oilfield Company Project (No. JS10-W-14-JZ-32-51)

摘　　要：Sustained casing pressure （SCP） in gas wells brings a serious threat to worker safety and environmental protection. According to geological conditions, wellbore structure and cement data of gas wells in the Sichuan-Chongqing region, China, the position, time, environmental condition and the value of SCP have been analyzed. On this basis, the shape of the pressure bleed-down plot and pressure buildup plot were diagnosed and the mechanism of SCP has been clarified. Based on generalized annular Darcy percolation theory and gas-liquid two-phase fluid dynamics theory, a coupled mathematical model of gas migration in a cemented annulus with a mud column above the cement has been developed. The volume of gas migrated in the annulus and the value of SCP changing with time in a gas well in Sichuan have been calculated by this model. Calculation results coincided well with the actual field data, which provide some reference for the following security evaluation and solution measures of SCP.Sustained casing pressure （SCP） in gas wells brings a serious threat to worker safety and environmental protection. According to geological conditions, wellbore structure and cement data of gas wells in the Sichuan-Chongqing region, China, the position, time, environmental condition and the value of SCP have been analyzed. On this basis, the shape of the pressure bleed-down plot and pressure buildup plot were diagnosed and the mechanism of SCP has been clarified. Based on generalized annular Darcy percolation theory and gas-liquid two-phase fluid dynamics theory, a coupled mathematical model of gas migration in a cemented annulus with a mud column above the cement has been developed. The volume of gas migrated in the annulus and the value of SCP changing with time in a gas well in Sichuan have been calculated by this model. Calculation results coincided well with the actual field data, which provide some reference for the following security evaluation and solution measures of SCP.

关 键 词：Sustained casing pressure gas migration coupled mathematic model gas well 

分 类 号：TE246[石油与天然气工程—油气井工程] TU998.1[建筑科学—市政工程]