| Fault sealing is the main factor of hydrocarbon accumulation in Wenchang A area, Pearl River Mouth Basin, where faulted traps developed. The Allan map is used to quickly evaluate the lateral sealing property of the faults, and with the actual drilling results, the applicability of the Allan map and the type of fault sealing are analyzed in the study area. It is shown that the Allan map can’t completely evaluated the lateral sealing character. Then the main parameters, SGR and SSF, are selected to setup SGR-SSF discrimination chart for quantitative study. According to seismic interpretation, SGR and SSF of the faults related to the drilling traps in Member-2 of Miocene Zhujiang Formation are obtained, and the SGR-SSF discrimination chart is set up combined with logging results of oil and water. It is shown that when SGR＞0.32 and SSF≤3.2, the fault sealing property is relatively good; when SGR≤0.25, or SSF＞4.2, it is the worst, with little possibility of oil accumulation; when 0.25＜SGR≤0.32 and SSF≤4.2, or SGR＞0.32 and 3.2＜SSF≤4.2, it is in the unproven area, with a certain potential. According to the charm, the lateral sealing feature of faults in E1 and W1 blocks of Wenchang A are analyzed. It is proved that the oil formation of ZJ2-3U、ZJ2-3M、ZJ2-3L、ZJ2-4U in high position of E1 block, and ZJ2-1L、ZJ2-3U、ZJ2-3L、ZJ2-4U of W1 block are relatively good in fault sealing condition, which could be the favorable targets for further exploration. |
