Abstract:
To accurately make resource evaluation is the prerequisite for development of natural gas hydrate resources, and the correct understanding of the characteristics of gas hydrate reservoir is the basis for such evaluation. The content and occurrence of gas hydrate are closely related to and affected by reservoir properties. The occurrence forms of gas hydrate, which includes pore-filling and fracture-filling, mainly depends on the nature and size of pores, fractures and other accumulation spaces in the marine sediments. Different types of hydrate reservoirs have different physical property response characteristics, which directly affects the accuracy of marine gas hydrate resource evaluation. The principles, evaluation parameters and applicability of the existing natural gas hydrate resource evaluation methods are different, and the occurrence type of hydrate is not considered. Based on the previous work, this paper puts forward a new method of "Detail Resource Evaluation" and "Precise Resource Evaluation" for marine natural gas hydrates. The "Detail Resource Evaluation" method based on small panel is suitable for the evaluation of pore-filled hydrate reservoir with rare drilling and dense geophysical survey network in favorable block; The "Precise Resource Evaluation" method based on the concept of "hydrate abundance in reservoir" is applicable to the accurate evaluation of small-scale hydrate orebody with dense well pattern in the well field, and can effectively improve the accuracy of the evaluation of fracture- filled types (e.g. massive, vein and nodule) hydrate resources.