塔中地区西北部良里塔格组沉积特征及其演化规律

良里塔格组作为优质储层，一直以来都是塔中地区勘探研究的重中之重，但对塔中北斜坡西北部(塔中85-49井区)沉积特征的研究尚且薄弱。综合利用岩心、薄片、测井和地震资料，将良里塔格组划分为3个三级层序、5个体系域和9~15个四级层序，建立了研究区的高精度层序地层格架，并识别出研究区发育的8种沉积微相类型，不同的沉积微相以特定的相序组合成礁滩复合体、中-高能粒屑滩、中-低能粒屑滩和泻湖-滩间海4种沉积相类型。在高精度层序地层与沉积特征研究的基础上，结合地震属性资料，分析了SQ1和SQ2时期的沉积相分布特征，重点总结了不同时期高位期和海侵期的沉积相剖面演化规律，并对比了各时期沉积相平面分布的差异性，从而揭示了沉积相的演化规律，有利于进一步指导本区今后的油气勘探工作。

Sedimentary Characteristics and Their Evolution of Lianglitage Formation in Northwestern Tazhong Area

The Lianglitage Formation, being the high quality reservoir, has always been the important target in the researches for exploration in Tazhong area. However, researches on the sedimentary characteristics of the northwestern part in the northern slope of Tazhong area (Tazhong 85-49 well) still inadequate. Based on cores, thin-sections, well-logging data and seismic data, the Lianglitage Formation is divided into 3 third-order sequences, 5 systems tracts and 9 to 15 fourth-order sequences, and the high-resolution sequence stratigraphy framework is established in the research area. 8 microfacies are identified in research area and according to their specific combination, 4 sedimentary facies are recognized in fourth-order sequence, including reef complex, medium-high energy grain bank, medium-low-energy grain bank and lagoons-sea. Distributional characteristics of sedimentary facies is studied, based on the foundation of high-resolution sequence stratigraphy and sedimentary characteristics, focusing on the analysis of the facies evolution pattern in cross-section of HST and TST in SQ1 and SQ2 and contrast of facies distributions in flat between different periods. As a result, the evolution pattern of sedimentary facies is revealed, which benefits the further guidance of the oil and gas exploration of research area in the future.