塔里木盆地巴楚—麦盖提地区志留—泥盆系油气成藏规律

Regulation of Silurian-Devonian hydrocarbon accumulation in Bachu-Maigaiti region of Tarim Basin

塔里木盆地巴楚—麦盖提地区以寒武—奥陶系海相碳酸盐岩为烃源岩,志留—泥盆系三角洲-滨岸砂岩为储层,潮坪环境形成的致密泥岩为盖层,形成了断裂型生储盖组合,具有较好的油气勘探前景。通过对研究区志留—泥盆系沉积相带展布、断层发育特征以及古隆起和古斜坡的综合研究,结合烃源岩排烃及已发现油气特征,认为巴楚—麦盖提地区志留—泥盆系油气成藏规律主要受沉积和构造的共同控制,在二叠纪末,寒武—奥陶系烃源岩排烃期已经形成的单斜构造或斜坡带,被长期活动断层沟通了寒武—奥陶系烃源岩的志留—泥盆系储层分布区易于形成油气藏。区内有利油气成藏区带主要为康2-方1井之间的断裂带与玉1-BK8-巴5井之间的斜坡带,可能发育的油气藏类型为岩性油气藏和构造-岩性复合油气藏。

In Bachu-Maigaiti region of Tarim Basin,the oil source rocks are Cambrian-Ordovician marine carbonate rocks,the reservoir is Silurian-Devonian delta-shoreland sandstone in character,and the cap rocks are tight mudstone by tidal,which formed a fault source-reserve-cap assemblage with better potential for petroleum exploration.Through comprehensive research on the distribution of sedimentary facies,characateristics of faults evolution and paleouplift and palaeoslope,combined with the expulsion of oil source rocks and the characateristics of founded oil and gas,it is concluded that the deposition and tectonic controled Silurian-Devonian hydrocarbon accumulation in this region.By the end of Permian,the uniclinal structure and slope regions formed in expulsion period of the Cambrian-Ordovician hydrocarbon source rocks connected with Silurian-Devonian reservoir by long lived faults are the favorable regions of hydrocarbon accumulation,represented by the fault zone between the K2~F1 wells and the slope zone between the Y1-BK8-B5 wells.The hydrocarbon reservoirs are lithologic and structural-lithologic reservoirs in type.