Method for evaluating shale gas preservation effectiveness in complex reconstruction areas

Abstract

The invention discloses a method for evaluating the shale gas preservation effectiveness in a complex reconstruction area. The method comprises the following steps: (1) selecting an effective hydrocarbon generating shale layer section; (2) evaluating the preservation effectiveness of shale gas in a vertical direction; (3) evaluating the plugging effectiveness of the shale gas in the horizontal direction; (4) evaluating the preservation effectiveness of shale gas; (5) according to the preservation effectiveness of the shale gas in the vertical direction and the plugging effectiveness of the shale gas in the horizontal direction and referring to the water concentration and pressure of a hydrocarbon stratum and number of hydrocarbon oxidizing bacteria, evaluating the advantages and disadvantages of a shale gas preservation condition in the complex reconstruction area, and finally defining a favorable for the development of the shale gas according to the advantages and disadvantages of thepreservation condition of the shale gas in the complex reconstruction area. The method can effectively evaluate the advantages and disadvantages of the preservation conditions of shale gas and further define the favorable areas for the development of the shale gas.

Description

technical field [0001] The invention belongs to the technical field of petroleum and natural gas exploration and development, and relates to a method for evaluating the effectiveness of shale gas preservation in complex transformation areas. Background technique [0002] In recent years, the exploration and development of shale gas in my country has developed vigorously, and shale gas in the Sichuan Basin has been commercially developed on a large scale. The development of shale gas can effectively reduce environmental pollution, make up for the shortage of oil and gas, and ensure energy security. As an unconventional oil and gas resource, shale gas has the characteristics of tight reservoir, low oil and gas abundance and wide distribution area. The United States is the country with the earliest exploration and development of shale gas and relatively mature technology at present, and its shale gas production ranks first in the world. The geological conditions for shale gas...

AI Technical Summary

Problems solved by technology

However, the identification of fractures of different scales is currently difficult due to the quality of seismic data, and there is a large gap in the study of fractures on the surface section underground, and the guidance for the analysis of fracture development in underground shale formations in complex reformed areas is not strong.

[0003] In the complex reformed area in the south, the number of wells drilled is relatively small, and it is difficult to directly drill wells to obtain the gas content and then evaluate the preservation conditions

Most of the complex reformed areas do not have 3D seismic data volumes. Even if there are 3D seismic data volumes, the quality is poor due to the existence of surface limestone. It is difficult to visually identify the formation thickness, fault development location and scale, and gas content. , so it is difficult to evaluate the pros and cons of shale gas preservation conditions in complex reformed areas, and it is impossible to delineate favorable areas for shale gas development in complex reformed areas

Images