Variations of In-situ Stress and Wellbore Stability for Kingfisher Block Through the Fault
DENG Jingen1, LIN Hai1, HU Lianbo1, CHEN Zijian1, YUAN Junliang1, LIU Zhaonian2
1. State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China;2. CNOOC Research Institute, Beijing 100027, China
Abstract：The development of faults is common in the Kingfisher block, causing frequently complicated situations, such as the wellbore collapse, the drilling fluid leakage and so on, in the process of drilling through faults. According to the pore elastic theory and the Mohr-Coulomb strength criterion, this paper analyzes the influence of the normal fault on the in-situ stress, which, combined with the influence of the faults on the formation and mechanical properties, is used finally to establish a prediction model of wellbore stability through faults. The research results show that the horizontal stress perpendicular to the fault trace increases significantly through the normal fault; meanwhile, the fault fracture zone develops near the fault, and reduces the formation strength and increases the collapse pressure. The safe mud density window of the drilling fluid is greatly reduced with the fault. In order to prevent the drilling fluid leakage due to the fault fracture zone, it is necessary to consider the minimum horizontal principal stress as the upper limit of the safe mud density window. The reasonable drilling fluid density and the good sealing property of the drilling fluid are the key of the safety of drilling. The results of the study provide some guidance for the solid drilling situation of the Kingfisher block and the drilling safety of the Kingfisher block through the fault.
邓金根;林海;胡连波;陈子剑;袁俊亮;刘兆年. Kingfisher区块过断层地应力变化规律及井壁稳定性[J]. , 2013, 31(23): 53-56.
DENG Jingen;LIN Hai;HU Lianbo;CHEN Zijian;YUAN Junliang;LIU Zhaonian. Variations of In-situ Stress and Wellbore Stability for Kingfisher Block Through the Fault. , 2013, 31(23): 53-56.
2013, Vol. 31 
