Abstract:
The lithology of the bedrock reservoirs in the Kunteyi area of the Qaidam Basin is complex, with diverse mineral components and rapid longitudinal and transverse changes. The reservoirs have developed fractures, exhibiting dual media storage space characteristics of fractures and matrix pores, and the degree of fracture and dissolution development is uneven. Core and thin section analysis data indicate that the reservoir is relatively dense, with matrix porosity ranging from 2−10%. Physical properties are not limited by burial depth, and the average matrix porosity is 5.4%. It is difficult to accurately evaluate the reservoir and effective reservoir division using conventional logging methods. This article comprehensively analyzes the comprehensive response characteristics of various lithologies, conducts sensitivity analysis of logging curves, calibrates logging based on X-ray diffraction data, and combines conventional logging curves with logging data, such as electrical imaging and array acoustic waves, to quantitatively evaluate parameters, such as matrix porosity, fracture porosity, porosity, pore area, and the connectivity index of bedrock reservoirs. Based on data from gas testing and production testing, an evaluation of the gas bearing properties of the bedrock reservoir was conducted, and a logging evaluation method suitable for the bedrock reservoir in the Kunteyi area was established. This provides technical support for the logging evaluation and gas production layer selection of exploration and development wells in this and similar gas reservoirs.