准西车排子凸起下石炭统地层划分及潜力分析

Stratigraphic Division and Exploration Potential Analysis of Lower Carboniferous in Chepaizi Uplift,Northwestern Junggar Basin

利用野外露头、地震及最新钻测井资料,对车排子凸起下石炭统地层进行细分,并开展勘探潜力分析。研究结果表明,车排子凸起下石炭统地层三分特征明显,自下而上依次发育太勒古拉组火山岩、包古图组火山岩与沉积岩互层及希贝库拉斯组沉积岩,3套地层在岩性特征、测井响应及地震反射等方面存在明显差异。平面上,太勒古拉组全区分布,南北向凹隆相间,包古图组和希贝库拉斯组呈南北向展布,向东向西削蚀尖灭。总体上,火山岩储层总体优于砂砾岩储层,火山角砾岩物性好于安山岩。太勒古拉组爆发相和中基性溢流相是储层发育的优势岩相,尤其东南部爆发相发育区,位于中等磁力异常范围,分布广,勘探潜力大。

This study uses field outcrops,earthquakes,and the latest drilling and logging data to subdivide the Lower Carboniferous strata in the Chepaizi Uplift,and to conduct exploration potential analysis.Our research indicates that the lower Carboniferous strata in the Chepaizi Uplift have obvious three-division characteristics.From bottom to top,there are volcanic rocks of the Tailegula Formation,interbedded volcanic rocks and sedimentary rocks of the Baogutu Formation,sedimentary rocks of the Xibekulas Formation,and three sets of strata in the rock.There are obvious differences in characteristics,logging response,and seismic reflection.In horizontal direction,the Tailgula Formation is distributed throughout the region,with north-south concave and uplifts alternating.The Baogutu Formation and the Xibekulas Formation spread out in a north-south direction,eroding and pinching east to west.In general,volcanic reservoirs are better than sand-conglomerate reservoirs,and volcanic breccias have better physical properties than andesite.The explosive facies and intermediate-basic overflow facies of the Tailegula Formation are the dominant lithofacies for reservoir development,especially the explosive facies development area in the southeast,which is located in the range of medium magnetic anomalies with wide distribution and great exploration potential.