柴达木盆地露头油藏的特征及其勘探前景

THE FEATURES AND EXPLORATION PROSPECT OF OUTCROP OIL ACCUMULATION IN QAIDAM BASIN

秦长文 庞雄奇

Qin Changwen Pang Xiongqi

中国石油人学石油天然气成藏机理教育部重点实验室, 北京, 102249 2. 中国石油大学盆地与油藏研究中心, 北京, 1022491

Key Laboratory for Hydrocarbon Accumulation Mechanism, Ministry of Education, Petroleum University, Beijing 102249, China 2. Basin and Reservior Research Center, Petroleum University, Beijing 102249, China

露头油藏是一种形成于露头(削顶)背斜翼部或盆地边缘单斜上依靠潜水面控制的特殊油藏,是今后石油勘探的一个新领域.通过对成藏条件和勘探结果的分析,可以看出柴达木盆地的鱼卡油田是一个不完整的削顶背斜,顶部无封闭条件,油藏靠潜水衬托;储油层物性好(孔隙度>17%);成藏晚,埋藏浅(120～450m),油质稀;靠重力方式开采,具有露头油藏的特征,应是一个露头油藏.柴达木盆地气候干燥,露头区潜水面埋深可达几十至几百米;油气资源丰富,发育大量的露头背斜,具有形成露头油藏的有利地质条件,勘探露头油藏的前景广阔.

Outcrop oil accumulation is a special accumulation which is located in the wing of an outcrop anticline or in a monocline in the edge of a basin and is controlled by water table.It is a new explorating field.Through analyzing the geological conditions of oil accumulating and the exploration results in Yuqia oilfield in Qaidam basin,some viewpoints are put forward.Yuqia oilfiold in Qaidam basin is in an uncomplete outcrop anticline without trapping in top.The oil accumulation is lifted by underwater.It forms late and has good oil reservoir rocks with porosity over 17%.The oil in Yuqia oilfield is thin and the buried depth of oil accumulation is from 120 to 450 meters.Being of these features,it is considered as an outcrop oil accumulation.Qaidam basin is arid now.The depth of water table is from tens to hundreds meters in outcrop areas.It is abound in petroleum resources.There are many outcrop anticlines in the basin.The prospects for the exploration of outcrop oil accumulation in Qaidam basin is broad.

国家重点基础研究发展规划“973”项目(G19990433).

https://doi.org/10.11781/sysydz200503256