摘要
The anticline is large in size and gentle.an individual structure covers an area up to 100-300.km*.At top of mudcone little tensional faults are often associated.The mudcones themselves are either possible source rock bodies or hydrocarbon-draining.pressure-releasing paths.Natural gas migrated upwards along mudcone diapir zone and faults.and accumulated in the upper structural.traps.The already drilled Dongfang 1-1 and Ledong 15-1 Structures are identified to bre gas-bearing structures.Some structures similar to them.such as Cangjiang 29-1.Ledong 8-3 and Ledong 16-1 Structures.are today's exploration targets.Most of this type of traps contain gas.But three aspects still need to be studied in future:firstly.overpressure and high-temperature result in difficulties of drilling engineering:secondly,reservoirs do not develop very well or are not high-quality:thirdly.there is non-hydrocarbon gas such as CO2 to be.associated with.so the fluid properties are more complicated.
