Distribution of Northern Platform Margin and Implications to Favorable Exploration Regions on Lower Cambrian Xiaoerbulake Formation,Tarim Basin

Key words: 
• the Northern platform margin /
• Xiaoerbulake Formation /
• Keping-western Tabei /
• Tarim Basin /

Abstract: Reef-bank dolomite is one of the most promising oil and gas reservoir types. Although the foundation of developing reef-bank dolomite type reservoir existed, the research of its characterization and distribution is fairly poor. In this paper, by using the methods of outcrop observation, single well data analysis, seismic data characterization, we identified the Lower Cambrian platform margin in Keping-western Tabei area, which was named as the northern platform margin. With the scale of 330 km length and 7km width, it extends as NE-trending. Outcrop data shows that the Lower Cambrian northern platform margin developed two periods of microbial reef, with the main lithology of pinhole dolomite developing dissolution pores. A group of seismic reflection units with mounded geometry can be seen in the seismic section clearly. The Northern platform margin located in the long-term developed ancient inherited uplift has a unique reservoir-cap configuration advantage, which makes it have the favorable conditions to form a large oil and gas field. The distribution of the northern platform margin has made clear the direction of play evaluation and target optimization in the Lower Paleozoic dolomite area.