RECOGNITION OF SLOPE BREAK BELTS AND ITS HYDROCARBON GEOLOGICAL SIGNIFICANCE

The intension and extension of the concept of slope break belts have changed obviously after its introduction as a key concept into sequence stratigraphy. Nowadays, the slope break belt is not only a term for a kind of geomorphological feature, but also a concept with more sedimentological meanings, that is from a topographic relief to a sedimentary body. The recognition and identification of a slope break belt affect the identification of sequence boundaries, the analysis of strata stacking pattern, the architectural analysis of systems tract, and the establishment of sequence stratigraphic model, and thus play an important role in the exploration and development of stratigraphic/lithologic oil and gas reservoirs. The authors have recently identified the depositional slope break belt and physiographical slope break belt in the Pearl River Mouth Basin using integrated geological and geophysical methods.The depositional slope break belt is developed in the south of Huizhou sag, and the physiographical slope break belt mainly developed on the north slope of Baiyun Sag. The type and place of slope break belt is variable with the evolution of the basin. Finally, the practical significance of the identification of slope break zone is concluded in the exploration and development of lithologic oil and gas reservoirs in the Pearl River Mouth Basin. Meanwhile, the identification method and the work flow of the slope break belt are proposed, which has a certain guiding significance to the identification of slope break belt in related basins.