| 柴达木盆地柴西南区震积岩的发现及其引发的勘探启迪 |
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| 引用本文： | 石亚军.柴达木盆地柴西南区震积岩的发现及其引发的勘探启迪[J].地质学报,2009,83(8):1178-1187. |
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| 作者姓名： | 石亚军 |
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| 作者单位： | 中国石油勘探开发研究院西北分院 |
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| 摘 要： | 随着勘探和开发的需要,岩性油气藏成为柴达木盆地西南区石油勘探的一个重要领域,然而由于受多期的构造叠加改造,致使柴西南区岩性油气藏分布规律不清,勘探接替领域不明确。笔者通过研究发现,由于受盆缘及其北西向二级断裂的影响,盆地西南区地震活动强烈,深、浅层均发现一系列与地震有关的震积岩,可见阶梯状小断层、液化砂岩脉、振动液化卷曲变形构造、砂火山、火焰状构造、假结核、震积砂枕、震积砂球构造、串珠状构造及震褶层等原地震积岩的软沉积物变形特征,另外可见地震引起的重力滑塌或泥石流形成的滑塌构造和角砾岩化变形特征,诸如震裂岩、震塌岩、自碎屑角砾岩、液化角砾岩、内碎屑副角砾岩等异地震积岩。事实上这些震积岩能够极大地改善储集层渗透性,使渗透率大幅度增加,为油气勘探和开发提供了新的视角和领域。更为重要的启迪是形成震积岩的古地震具有重要的触发机制,很容易引起三角洲前缘相的岩性发生滑塌,进而形成滑塌扇、浊积等一系列沉积现象,这种储集体将成为油田储量增长的新亮点,本着这种思想,笔者通过叠前地震多属性的预测及先进的叠前AVO反演预测,在柴西南区跃东斜坡带发现这种滑塌体的存在,并建立了相应的沉积模式图。这样将可能突破了以往该区“环凹找油”的勘探思路,明确提出了古凹陷区仍然是柴西南区寻找岩性油气藏的一个主要领域。
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| 关 键 词： | 震积岩 滑塌扇 岩性油气藏 勘探领域 柴达木盆地 |
| 收稿时间： | 1/7/2009 2:51:16 PM |
| 修稿时间： | 7/6/2009 4:10:10 PM |
The Found of Seismites in the Southwestern Area of the Qaidam Basin |
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| shiyajun.The Found of Seismites in the Southwestern Area of the Qaidam Basin[J].Acta Geologica Sinica,2009,83(8):1178-1187. |
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| Authors: | shiyajun |
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| Institution: | Research institute of petroleum exploration & development-northwest,petrochina |
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| Abstract: | With the increasing need for exploration and development, lithologic reservoir has become an important domain for oil and gas exploration in southwestern Qaidam Basin. However, due to multiphase tectonic overprinting activities, the distribution of lithologic reservoir in southwestern Qaidam Basin is indistinct and the next exploration area is indefinite. Through this study, seismic activity is found to be very intensive in southwestern basin due to the influence of basin edge and northwestern second order fault. Seismites related to earthquake are found in deep and shallow beds. Lots of deformation structures are found, such as small step faults, liquid sandstone dikes, vibrating liquid curling structures, sand volcanos, flame structures, pseudoconcretions, seismite sand pillows, seismite sand ball structures, pinch and swell structures, etc. Some rock types are also observed, such as folding seismites, cracked seismites, autoclastic breccias, intraclastic subbreccias. In fact, these smites can greatly increase the permeability of reservoir, which provides a new perspective for oil and gas exploration and development. More importantly, the paleoearthquake is a significant event that triggers seismites, initiates a landslide at the delta front easily, and creates some sediment phenomenon, such as slump fans and turbidities. This kind of reservoir will become a new growth point of reserves. With this thought, by seismic pre-stack multi-attribute prediction and advanced pre-stack AVO inversion prediction, slip blocks are found on Yuedong ramp region in southwestern Qaidam Basin and deposition model is built correspondingly. This might be a breakthrough of previous exploration ideas of \"search for oil around sags\" in this area. It is clearly put forward that paleosag is still an important exploration domain for lithologic reservoirs. |
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| Keywords: | seismites slump fans lithologic reservoirs exploration domain Qaidam Basin |
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