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

摘要： 深层-超深层是目前油气勘探的重点领域,寻找规模优质储层是实现深层-超深层油气勘探突破的关键。构造作用、沉积相和成岩相对优质碎屑岩储层的形成与发育具有重要影响,其中,沉积相是优质储层形成的基础,成岩相是优质储层发育的关键,构造作用通过影响裂缝发育和地应力场来改善储层品质。以库车坳陷白垩系巴什基奇克组储层为例,分析深层-超深层碎屑岩储层的基本特征,从沉积微相、成岩相和构造(裂缝、地应力)"三元控储"的角度揭示了深层-超深层储层品质的控制因素。沉积背景和成岩相控制了深层-超深层储层基质孔隙的形成与发育,裂缝可改善储层的渗透率和产能,不同构造样式下现今地应力的差异分布控制了基质孔隙保存和裂缝有效性。基于"三元控储"机理、成岩综合系数和储集物性,将库车坳陷深层-超深层储层划分为4类,其中,优质储层主要形成于高能水动力环境和低应力场背景,经历了弱-中等压实作用和弱胶结作用,溶蚀作用和裂缝发育常叠加改善储集物性。综合常规测井资料和成像测井资料分别建立了沉积微相、成岩相、裂缝发育和地应力场的测井评价方法,实现了库车坳陷白垩系深层-超深层优质砂岩储层的测井预测。研究方法与认识可以为开展深层-超深层储层综合评价与有利区带预测提供理论指导与技术支持。

关键词: 深层—超深层, 沉积微相, 成岩相, 裂缝, 地应力, 测井评价