Construction method for micro fracture-pore structure classification plate of granite reservoir

Abstract

The invention relates to a construction method for a micro fracture-pore structure classification plate of a granite reservoir. The method comprises steps as follows: a core section, which is not artificially destructed, of a target reservoir is selected; the porosity and permeability of a core section column sample are measured, and CT scanning and a mercury injection displacement experiment are performed on the core section column sample; the core section column sample is sampled for production of a casting body sheet, and the casting body sheet is observed under a microscope and counted; comprehensive analysis is performed according to the porosity and the permeability of the core section column sample, a CT scanning result and a mercury injection displacement experiment result as well as observation and counting results of the casting body sheet under the microscope, the permeability and the porosity are taken as main bases of classification, preliminary classification of the structure of the target reservoir is completed, and the micro fracture-pore structure classification plate of the target reservoir is established. The method is applicable to volcanic fractured reservoirs and can also be applied to fractured reservoirs such as carbonate rock reservoirs, compact sandstone reservoirs and the like and has high adaptability and popularization value.

Description

technical field [0001] The invention belongs to the geological technical field of exploration and development of offshore oil and gas fields, and in particular relates to a method for constructing a microscopic fracture-pore structure classification map of granite reservoirs. Background technique [0002] The main storage and seepage space of granite buried hill reservoirs is fractures, followed by dissolution pores. As the main seepage storage space, fractures exist in multiple levels of different sizes and scales. Among them, large fractures are important to the storage seepage capacity of the reservoir, but the storage space of micro and small fractures and dissolved pores is large, and their reserves account for the total reserves. More than 50% of. The actual production data of the oilfield proves that micro- and small fractures and dissolved pores make important contributions to the recovery factor during oil and gas development; in addition, micro- and small fracture...

AI Technical Summary

Problems solved by technology

However, the current research on pore (cavity)-throat (fracture) structure is mainly aimed at clastic rocks and carbonate rocks. The pore types of ordinary clastic rocks are mainly pores, and the classification method is mainly based on pore-throat characteristics and pore structure. The size of the seepage capacity is large, and few fractures are involved; the type of carbonate storage space is complex, and pores, caves, and fractures often develop at the same time, and the storage space and seepage channels are dominated by dissolution pores or caves. The shape and connectivity of caves and fracture parameters are not used as the main basis for classification; therefore, there is no related systematic research on the fracture-pore structure of volcanic rock buried hill reservoirs with fractures as the main storage and seepage space

Images