柴北缘鄂博梁构造带油气成藏条件及勘探部署

柴达木盆地北缘鄂博梁构造带由鄂博梁Ⅰ号、鄂博梁Ⅱ号、鄂博梁Ⅲ号和葫芦山4个地面构造组成。近期的综合研究和老井复查表明:该区带具有优越的天然气成藏条件:位于侏罗系生气凹陷之内、发育大型构造圈闭、具有优质储层和良好储盖组合以及深大断裂沟通气源,发育源内和源上两种成藏模式。近期,邻近的牛东构造获得重大突破,其他构造已钻井都有气显示,并且鄂7井获得工业气流。在成藏条件和目前勘探现状综合分析的基础上,提出该区优先风险钻探鄂博梁Ⅰ号构造;积极准备其他构造,其中以开展精细地震勘探鄂博梁Ⅲ号构造为重点,精细落实圈闭后投入勘探。

Oil and Gas Accumulation Conditions of Eboliang Structural Belt on Northern Periphery of Qaidam Basin and Exploration Strategy

Eboliang structural belt on the northern periphery of Qaidam Basin is composed of four surface structures - Eboliang No. Ⅰ, Eboliang No. Ⅱ , Eboliang No. Ⅲ and Hulushan. The latest study and re-investigation of old wells indicate that this belt has good conditions for natural gas accumulations, because it is located in the Jurassic gas sourcing depression with development of large-scale structural traps, high-quality reservoir-cap assemblages and the deep and large faults that connect gas sources. There are two patterns for gas accumulations - within the source and above the source. Significant breakthroughs have been made in the nearby Niudong structure in recent time. Gas show was found in drilling of other structures. In addition, E-7 Well obtained an industrial gas flow. Based the accumulation conditions and analysis of the current exploration conditions, this paper proposes to drill exploration wells first in Eboliang No. I structure in this belt while making active preparations for other structures. Meanwhile, the detailed seismic exploration efforts should be focused on Eboliang No. Ⅲ structure to locate the trap for exploration.