准噶尔盆地八道湾组湿地扇三角洲沉积特征

Humid Fan-delta Sedimentation Characteristics in the Badaowan Formation in the Northwestern Junggar Basin

邱争科 王辉 李婷 陶武龙 蒲波

QIUZhengke WANGHui LITing TAOWulong PUBo

中国石油新疆油田分公司采油二厂, 新疆 克拉玛依 834000 中油南充燃气有限责任公司, 四川 南充 637000

No.2 Oil Production Plant, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China Zhongyou Nanchong Gas Limited Company, Nanchong, Sichuan 637000, China

准噶尔盆地西北缘侏罗系八道湾组油气资源丰富，但主要分布在克乌断裂带东南侧砂砾岩储层中。近期的勘探表明，远离断裂带的盆地区油气显示丰富，具有较强的勘探潜力，但研究区沉积相类型和展布方面的认识尚属空白。在钻井、测井、岩芯以及地球物理资料综合分析的基础上，将八道湾组划分为两个三级层序，并识别出扇三角洲相、辫状河流相、辫状河三角洲相以及湖泊相等。八道湾组下部层序广泛发育扇三角洲相，上部层序以发育辫状河流相和辫状河三角洲相为特征。研究区扇三角洲相为潮湿环境下形成的，具有分布面积广，粒度细，前缘厚度大，平原富含油的特征，这与中国东部地区古近系断陷盆地中发育的干旱扇三角洲明显不同。

There are abundant oil and gas resources in the Jurassic Badaowan Formation at the northwestern margin of the Junggar Basin, but they are mostly located in the sand-conglomerate reservoirs on the southeastern side of the Ke-Wu fault belt. Recent exploration reveals that there are plentiful oil and gas reserves and higher exploration potential in the basin area far away from the fault belt. There is, however, little knowledge of the types and distributions of the sedimentary facies in the study area. Based on an integrated analysis of data obtained from well drilling and logging, core samples, and geophysical measurements the Badaowan Formation is divided into two three-fold stratigraphic sequences and various facies, including fan-delta facies, braided river facies, braided river delta facies, and lake facies, are identified. Fan-delta facies dominate the lower sequence of the Badaowan Formation, while the upper sequence is characterized by braided river and braided river delta facies. The fan-delta facies in the study area formed in humid environments. They are widely distributed, fine-grained, thick at the facies fronts and oil-rich in the plains. These facies are clearly different from the arid fan-delta facies developed in the Paleogene rift basins in Eastern China.

10.11885/j.issn.1674-5086.2017.07.18.01