阿尔及利亚阿拉尔高生储盖组合特征

阿拉尔高位于阿尔及利亚撒哈拉地台东部三叠盆地和西部古生界盆地的过渡带,是海外油气勘探的重要战略区。在区域构造-沉积演化分析的基础上,对阿拉尔高地区生储盖组合发育特征进行了研究。结果表明:阿拉尔高发育良好的生储盖组合,志留系热页岩是主力烃源岩,自下而上发育三套储盖组合,海西运动对储盖组合的分布具有重要控制作用。第一套寒武~奥陶系河流~滨浅海相砂岩储层厚度大,但由于缺少海西期的暴露风化、地表水的淋滤溶蚀,储层致密,物性差,尚无油气发现;第二套下泥盆统下临滨储层在海西期轻微剥蚀,分布比较广泛,砂岩薄,但物性好,已发现Reg Mouaded 1和Reg Mouaded Sud-est 1气藏;第三套上泥盆统~下石炭统障壁海岸相砂岩在海西期遭受强烈抬升剥蚀,仅在阿拉尔高西侧有部分残留,障壁沙坝和潮汐水道是主力储层;该研究结果为北非地区油气勘探开发提供了重要的地质依据。

Source-reservoir-cap assemblages of the Allal High, Algeria

Allal high located on the transition zone from the eastern Triassic Basin to the western Paleozoic Basin, and it was an important strategic area for the overseas petroleum exploration. With the instruction of the principle theory of petroleum geology, we analyzed the source-reservoir-cap assemblages of the Allah high based on the regional tectonic and sedimentary evolution study. The studies showed that it developed good source-reservoir-cap assemblages in this area. The Silurian hot shales were the major source rocks and there were three reservoir-cap assemblages from bottom to top which controlled by Hercynian. The three reservoirs include (1) The thick and tight reservoir of Cambrian and Ordovician sandstone. It lacks the Hercynian exposure and corrosion, mainly fluvial-offshore sandstones. (2) The widely distributed lower shore face sandstones in lower Devonian, are thin with good porosity. It has found the Reg Mouaded 1 and the Reg Mouaded Sud-est 1 fields. (3) The barrier sandstones in upper Devonian and lower Carboniferious, only remained in western of Allal High because of the strong Hercynian erosion . The barrier bar and tidal channel sands are major reservoirs; This study provides important geological basis for the exploration and development of north Africa area.