关键词: 湖底扇, 测井相标志, 地震相标志, 沉积特征, 沉积模式, 下白垩统, BG 盆地

Abstract:

In order to judge lateral sealing of fault more easily, based on the study of lateral sealing mechanism of fault and its influencing factors, minimum value of mudstone content required in lateral sealing of fault was forecast through comparing displacement pressure of fault rock and sealed reservoir. A method for judging lateral sealing ability of fault by using mudstone content of fault rock was established, and it was applied to judge the lateral sealing of No.1-7 reservoirs in lower Ed₃ of f-np5-2 fault in No. 5 structure of Nanpu Depression. The result indicates that mudstone content of fault rock in No. 1, 2, 3 and 6 reservoirs in lower Ed₃ of f-np5-2 fault is more than the minimum value of mudstone content of fault rock required in lateral sealing of fault. The faults are sealed laterally, which is favorable for oil and gas accumulation, so drilling shows oil layer. Mudstone content of fault rock in No. 4, 5 and 7 reservoirs in lower Ed₃ of f-np5-2 fault is less than the minimum value of mudstone content of fault rock required in lateral sealing of fault. The faults are unsealed laterally, which is unfavorable for oil and gas accumulation, so drilling shows water layer. The judging result accords with oil and gas distribution in lower Ed₃ of NP503 well currently, which indicates that the method is feasible to judge lateral sealing of fault.

Key words: sublacustrine fan, log facies marks, seismic facies marks, sedimentary characteristics, sedimentary model, Lower Cretaceous , BG Basin