论文详情
四川盆地磨溪地区龙王庙组为典型的局限台地沉积,明确其沉积相类型及其井震响应特征可以较好地指导该段储层的空间展布预测。为此,分析了岩心、镜下薄片、测井和地震等资料,结合前人研究成果,明确磨溪地区龙王庙组的沉积相类型和特征,分析并总结了各亚相的测井、地震响应特征,编制了连井相剖面和沉积相模式图,最后基于多属性拟合方法预测得到的颗地比值(颗粒岩累计厚度与地层厚度之比)分布并结合最大正振幅属性分布,圈定有利相带展布区域,建立磨溪地区龙王庙组沉积地震相模式。研究认为:磨溪地区龙王庙组沉积时期主要发育云坪、滩间洼地、台内滩和潟湖4种沉积亚相,纵向上表现出多滩体叠合的发育特征,且滩体沉积厚度大,横向上表现出东西向滩体连通性好的特征;基于地震剖面反射特征识别了3种地震相类型,分别对应于滩间洼地亚相(Ⅰ类)、台内滩滩翼(Ⅱ类)和台内滩滩核(Ⅲ类)微相,进而明确了3套“Ⅱ类Ⅲ类Ⅱ类”地震相展布组合关系;在研究区西部、南部和东部圈定了3个台内滩主体分布区,作为龙王庙组的有利沉积相带展布区域;总结了从滩间洼地滩翼滩核滩翼滩核滩翼滩核滩翼滩间洼地的“三滩”(即3个滩主体)的沉积模式及展布特征,为类似储层的勘探开发提供了指导思路。
The Longwangmiao Formation in the Moxi Block of the Sichuan Basin is a typical restricted platform.Clarifying the type of sedimentary facies and the characteristics of the well-seismic response can aid the prediction of the spatial distribution of reservoirs in this section.Therefore,observations from the cores and slices were analyzed,along with the observation and logging of seismic data combined with previous research results.This way,the types and characteristics of the sedimentary facies of the Longwangmiao Formation could be elucidated.Furthermore,the characteristics of the logging data and the seismic response of each subfacies were analyzed to produce a well-connected section and a model map of the sedimentary facies.Finally,the ground ratio predicted via the multi-attribute fitting method was combined with the maximum positive amplitude distribution,so that the location of the belt containing the favorable facies could be delineated,and the model of sedimentary seismic facies in the Longwangmiao Formation could be established.The results presented in this study allowed the restricted platform facies of the Longwangmiao Formation to be divided into four sedimentary subfacies,namely the dolomitic flat,inter-shoal low,intra-platform shoal,and lagoon subfacies.In the vertical direction,they are characterized by the superposition of multiple shoal bodies.Moreover,the shoal bodies have a large sedimentary thickness.Horizontally,the shoal bodies show good connectivity in the East-West direction.Three types of seismic facies were identified based on the reflection characteristics of the seismic section,corresponding to the following sub/micro-facies types:inter-shoal low (Ⅰ-type),beach margin (Ⅱ-type),and beach core (Ⅲ-type).Furthermore,three sets of type-Ⅱ- type-Ⅲ-type-Ⅱ seismic facies were identified.In the western,southern,and eastern parts of the study area,three main areas where intra-platform shoals are abundant were identified.These areas correspond to the favorable sedimentary facies belt of the Longwangmiao Formation.The sedimentary model and distribution characteristics of the “three shoals” were summarized.Overall,the results presented in this study can provide guidance for exploration and development of similar sedimentary reservoirs.
国家科技重大专项(2016ZX05047-002,2016ZX05061-001)和国家自然科学青年基金项目(41804120)共同资助。