准噶尔盆地南缘山前冲断带芦草沟组储层含气性及主控因素分析——以米参2井为例

在野外地质考察、重磁电勘探成果基础上,在准噶尔盆地南缘山前冲断带乌鲁木齐一带进行了页岩气参数井——米参2井施工。综合钻探、地质综合录井、测井和分析测试数据,进行该区芦草沟组泥页岩储层含气性评价,并对储层有机碳含量、孔隙度、矿物组分和页岩裂缝发育特征等方面进行研究。分析储层含气性主控因素,旨在对识别准噶尔盆地南缘山前复杂构造带页岩气“甜点”及勘探开发提供地质依据。结果表明,该区芦草沟组泥页岩含气层累计有效厚度206.9 m(34层),其中气层有效厚29 m(3层),最大总含气量1.64 m³/t;储层总含气量与有机碳含量、核磁有效孔隙度和矿物成分之间相关性较弱,与核磁自由流体孔隙度和裂缝密度呈较好的正相关,认为在准噶尔盆地南缘山前冲断带,应以在远离断裂的构造相对稳定区域寻找裂缝型“甜点”为主。

Analysis of Gas-Bearing Properties and Main Controlling Factors of the Lucaogou Formation Reservoir in the Piedmont Thrust Belt,South Margin of Junggar Basin-Take MC02 Well as an Example

On the basis of field geological investigation and gravity,magnetic and electric exploration results,a shale gas parameter MC02 well was constructed in Urumqi area of piedmont thrust belt in the southern margin of Junggar basin.Based on the comprehensive drilling,geological logging,logging and analysis of test data,the gas bearing property of Lucaogou Formation shale reservoir is evaluated in this area.The organic carbon content,porosity,mineral composition and fracture development characteristics of shale are studied.The main controlling factors of gas bearing property of reservoir are analyzed.The purpose of this study is to provide a geological basis for identifying the"sweet spot"of shale gas and exploration and development in the Piedmont complex structural belt in the southern margin of Junggar Basin.The results show that there are 34 gas-bearing shale gas layers in the Lucaogou Formation in this area,with a cumulative effective thickness of 206.9 m,including 29 m(3 layers),177.9 m(31 layers),and a maximum gas content of 1.64 m³/t;The total gas content of the reservoir is not significantly correlated with TOC,NMR effective porosity and mineral composition,and has a good positive correlation with the NMR free fluid porosity and crack density.It is believed that the piedmont complex structural belt in the southern margin of the Junggar Basin should look for"crack-type sweet spots"in the relatively stable area far from the fault.