Characterization of Organic Pores within High-Maturation Shale Gas Reservoirs

Shale gas is a very important natural resource which can significantly affect the natural gas production of the world (e.g., in United States, Canada, and China). The organic matter within shale is the material that generates hydrocarbons, such as natural gas, under high thermal maturity. Throughout this process, a significant amount of pores within organic matter, called organic pore, are also generated, as the organic matter itself becomes a porous solid. These organic pores contribute significantly to the overall gas storage and flow of the reservoir as a whole. These organic pores are especially important to the process of gas adsorption and desorption within organic pores, which makes the storage and flow of shale gas very different from conventional reservoirs. The structure of organic pores, including pore volume, surface area, geometry, size distribution, etc., is significant to understanding their influence upon gas adsorption and desorption and gas flow. Thus, it is necessary to quantitatively analyze these organic pores; however, studies that quantitatively analyze organic pore structure in detail are rare. By better understanding characteristics and relationships of these pores through statistical analysis, it is possible to be able to ascertain more characteristics of the reservoir as a whole. Therefore, this research aims to develop the quantitative method to characterize pore structure and discuss the feature of pore structure of high-maturity shale samples from the Sichuan Basin.