Geological Components of the Cooper Preliminary Assessment Extent (PAE v03)

## **Abstract** \n\nThis dataset was derived by the Bioregional Assessment Programme. The parent dataset is identified in the Lineage field in this metadata statement. The processes undertaken to produce this derived dataset are described in the History field in this metadata statement.\n\n\n\nThe first step in deriving the Cooper Preliminary Assessment Extent (PAE) was geologically-based. This involved assessing the extent of coal seams occurring in the Patchawarra and Toolachee formations in the Cooper Basin. These two units are the most prospective for coal seam gas as a result of their extensively developed coal seams, the depth of these seams and the inferred thermal history of the formations. Depths to the Permian coal measures preclude resource development by mining. Although coal occurs in other shallower formations, such as the Winton Formation, no economic deposits have been defined in the Cooper subregion. Screening criteria used in defining the geological components of the PAE were:\n\n\n\n\\*\tPatchawarra and Toolachee formation tops at depths less than 2000m; and \n\n\\*\tcumulative coal thicknesses in these formations of greater than 0 m\n\n\n\nThese criteria are used as they represent current maximum depths of extraction for coal seam gas (CSG), and the assumption that CSG will not occur in areas without coal. These also represent areas which do not also have resources of shale, basin centred, tight or conventional gas, which only occur at depths greater than 2000 m.\n\n\n\nThis resulted in the delineation of "Patchawarra PAE" component and "Toolachee PAE" component polygons. These two polygon features were merged to derive a Geological Components polygon.\n\n## **Purpose** \n\nThis dataset was used in the compilation of the Cooper PAE.\n\n## **Dataset History** \n\nThis dataset was created by extracting the extent of the Patchawarra and Toolachee formations, from the Cooper Formation Merged Isopach Grids v01 (GUID: 4b1fd4bd-e109-435b-a97d-01fd35ae1b67\t) dataset rasters, where:\n\n\n\nThe formation tops are at depths less than 2000m; and \n\nThe cumulative coal thicknesses in these formations are greater than 0 m\n\n\n\nThese extents were extracted as polygons and merged to create this dataset.\n\n## **Dataset Citation** \n\nBioregional Assessment Programme (2014) Geological Components of the Cooper Preliminary Assessment Extent (PAE v03). Bioregional Assessment Derived Dataset. Viewed 27 November 2017, http://data.bioregionalassessments.gov.au/dataset/23851dee-ce38-4734-891b-7b9cac47240d.\n\n## **Dataset Ancestors** \n\n* **Derived From** [Geological Survey of Queensland Cooper formation thickness grids v01](https://data.gov.au/data/dataset/2cabb0d5-1d99-494b-9497-2bf107bf2bdd)\n\n* **Derived From** [Cooper Basin Seismic Mapping Grids, South Australia](https://data.gov.au/data/dataset/cdd1625e-64e1-41da-bff4-2e26d0fd4ad1)\n\n* **Derived From** [Cooper Formations Merged Isopach Grids v01](https://data.gov.au/data/dataset/4b1fd4bd-e109-435b-a97d-01fd35ae1b67)\n\n

**摘要**

本数据集由生物区域评估计划（Bioregional Assessment Programme）衍生生成。其父级数据集已在本元数据声明的「谱系（Lineage）」字段中予以标注，本衍生数据集的制作流程详见元数据声明中的「历史（History）」字段。

库珀盆地初步评估范围（Preliminary Assessment Extent, PAE）的地质推导第一步基于地质学方法，即评估库珀盆地帕奇沃拉组（Patchawarra Formation）与图拉奇组（Toolachee Formation）内煤层的分布范围。由于这两套地层广泛发育煤层、煤层埋深条件适宜且具备推断的地层热演化历史，它们是库珀盆地内煤层气（coal seam gas, CSG）勘探潜力最高的层位。二叠纪煤系地层的埋深使得通过采矿法开发煤炭资源不具备可行性。尽管温顿组（Winton Formation）等其他浅层地层也有煤炭赋存，但库珀次区域内尚未发现具有经济价值的煤层矿床。用于界定PAE地质组分的筛选标准如下：

* 帕奇沃拉组与图拉奇组的地层顶界埋深小于2000米；
* 上述地层的累计煤层厚度大于0米

采用上述筛选标准的依据在于：其对应了当前煤层气开采的最大埋深上限，且默认无煤层分布区域不会产出煤层气；同时，符合该标准的区域也不发育页岩气、盆地中心气、致密气或常规气资源——这类非常规与常规天然气资源仅分布于埋深大于2000米的地层中。

由此圈定出「帕奇沃拉PAE组分」与「图拉奇PAE组分」两个多边形要素，将二者合并后即可得到本数据集的地质组分多边形成果。

**用途**

本数据集用于库珀PAE的编制工作。

**数据集历史**

本数据集通过以下流程生成：从「库珀地层合并等厚网格v01（Cooper Formation Merged Isopach Grids v01）」数据集的栅格数据中提取帕奇沃拉组与图拉奇组的分布范围，提取条件为：

* 地层顶界埋深小于2000米；
* 上述地层的累计煤层厚度大于0米

上述提取的范围被转换为多边形要素并进行合并，最终得到本数据集。该源数据集的全局唯一标识符（Globally Unique Identifier, GUID）为：4b1fd4bd-e109-435b-a97d-01fd35ae1b67

**数据集引用**

生物区域评估计划（2014）：《库珀盆地初步评估范围地质组分（Cooper Preliminary Assessment Extent (PAE v03)）》。生物区域评估衍生数据集。查阅日期：2017年11月27日，http://data.bioregionalassessments.gov.au/dataset/23851dee-ce38-4734-891b-7b9cac47240d.

**数据集溯源**

* **衍生自** [昆士兰地质调查局库珀地层厚度网格v01](https://data.gov.au/data/dataset/2cabb0d5-1d99-494b-9497-2bf107bf2bdd)
* **衍生自** [南澳大利亚库珀盆地地震制图网格](https://data.gov.au/data/dataset/cdd1625e-64e1-41da-bff4-2e26d0fd4ad1)
* **衍生自** [库珀地层合并等厚网格v01](https://data.gov.au/data/dataset/4b1fd4bd-e109-435b-a97d-01fd35ae1b67)