关键词: 深层—超深层, 沉积微相, 成岩相, 裂缝, 地应力, 测井评价

Abstract: Currently, deep to ultra-deep reservoirs are the key areas of oil-gas exploration, and searching for large-scale high-quality reservoirs is the key to achieving breakthroughs in deep to ultra-deep oil-gas exploration. Tectonism, sedimentary facies and diagenetic facies play an important role in the formation and development of high-quality clastic reservoirs. Among them, sedimentary facies provide the basis for the formation of high-quality reservoirs, diagenetic facies are the key to the development of high-quality reservoirs, and tectonism can improve the quality of reservoirs by exerting effects on fracture development and crustal stress field. Taking reservoirs of the Cretaceous Bashijiqike Formation in Kuqa depression as an example, the paper analyzes the basic characteristics of deep to ultra-deep clastic reservoirs, and reveals the controlling factors for the quality of deep to ultra-deep reservoirs from the perspective of "three-element reservoir control" involving sedimentary microfacies, diagenetic facies and tectonics (fracture and crustal stress). The sedimentary background and diagenetic facies control the formation and development of matrix pores in deep to ultra-deep reservoirs. Fractures can improve the permeability and productivity of reservoirs. The current differential distribution of crustal stress under different tectonic styles controls the preservation of matrix pores and the effectiveness of fractures. Based on the "three-element reservoir control" mechanism, the integrative modulus of diagenesis, and reservoir properties, the deep to ultra-deep reservoirs in Kuqa depression are divided into four categories. Among them, high-quality reservoirs are mainly formed in high-energy hydrodynamic environments and low stress field backgrounds, and have undergone weak to medium compaction and weak cementation. Reservoir properties can be improved jointly by dissolution and fracture development. The logging evaluation methods of sedimentary microfacies, diagenetic facies, fracture development and crustal stress field were established based on conventional logging data and imaging logging data, respectively, thus realizing the logging prediction of the Cretaceous deep to ultra-deep high-quality sandstone reservoirs in Kuqa depression. These research methods and understandings can provide theoretical guidance and technical support for conducting comprehensive evaluation of deep to ultra-deep reservoirs and predicting favorable zones.

Key words: deep to ultra-deep, sedimentary microfacies, diagenetic facies, fracture, crustal stress, logging evaluation