Abstract This work presents the first detailed research on the subsurface stratigraphy of the sedimentary Snake Cave Interval (late Early to late Middle Devonian) in the Bancannia Trough, the westernmost component of the Darling Basin, in western New South Wales, Australia. The study is based on data from wireline-log responses (especially gamma-ray and sonic logs), and core and cuttings descriptions in three exploration wells that are used to develop a model for depositional environments in the Bancannia Trough. This study provides re-evaluation and re-interpretation of the positions of the top and bottom boundaries of the Snake Cave Interval using distinct patterns changes in gamma-ray and sonic log signatures in relation to lithological characteristics in the Bancannia South-1, Bancannia North-1 and Jupiter-1 wells. The log facies interpretation of the Snake Cave Interval section enabled the detailed facies description of four lithostratigraphic units (A, B, C and D, in ascending order) in the study area. The Snake Cave Interval displays units with ten distinct sedimentary facies identified from core and then tied to the gamma ray log characteristics, forming facies associations that are visible in both vertical and lateral sections. Five facies associations have been identified: FA-I, braided fluvial multistory channel belt complex deposits; FA-II, meandering fluvial distributary channel sandstone complex deposits; FA-III, sandy braided fluvial distributary channels deposits; FA-IV, meandering fluvial deposits; and FA-V, fluvial channel-fill association with fluvio-tidal transition zone complex deposits. Detailed comparison of lithologic logs with wireline-log suite signatures (mainly gamma-ray logs) that are dominantly braided fluvial and meandering fluvial deposits, with minor fluvio-tidal transition zone complex deposits in this trough. This article presents a new depositional model that will promote exploration and discovery of potential petroleum resources and stratigraphic-trap configurations in this trough and adjacent regions of the Darling Basin.

中文翻译：

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澳大利亚东南部新南威尔士州西达令盆地班坎尼亚海槽蛇洞区间地下地层沉积环境的相分析关系

摘要 这项工作首次详细研究了澳大利亚新南威尔士州西部达令盆地最西端的 Bancannia 海槽中沉积蛇洞区间（晚早泥盆世至晚中泥盆世）的地下地层学。该研究基于来自电缆测井响应（尤其是伽马射线和声波测井）的数据，以及用于开发班坎尼亚海槽沉积环境模型的三个勘探井的岩心和岩屑描述。本研究利用与 Bancannia South-1 和 Bancannia North 的岩性特征相关的伽马射线和声波测井特征的不同模式变化，对蛇洞区间的顶部和底部边界的位置进行了重新评估和重新解释-1 和 Jupiter-1 井。蛇洞区间剖面的测井相解释使研究区四个岩石地层单元（A、B、C、D，按升序排列）的详细相描述成为可能。Snake Cave Interval 显示了具有 10 个不同沉积相的单元，这些沉积相从岩心中识别出来，然后与伽马射线测井特征联系起来，形成在垂直和横向剖面中都可见的相组合。已确定五个相组合：FA-I，辫状河流多层河道带复合沉积物；FA-II，蜿蜒河流分流河道砂岩复合矿床；FA-III，砂质辫状河流分流河道沉积；FA-IV，蜿蜒河流沉积；和 FA-V，与潮汐过渡带复合沉积物的河流河道充填组合。岩性测井与电缆测井组特征（主要是伽马射线测井）的详细比较，这些特征主要是辫状河流和蜿蜒河流沉积物，在该槽中有少量的潮汐过渡带复合沉积物。本文提出了一种新的沉积模型，它将促进达令盆地该海槽和邻近地区潜在石油资源和地层圈闭构造的勘探和发现。