准噶尔盆地新光地区佳木河组致密砂岩气有利区资源潜力综合分析

Comprehensive analysis of tight sandstone gas resource potential in the favorable area of Jiamuhe Formation in Xinguang area,Junggar Basin

准噶尔盆地中拐凸起新光地区二叠系佳木河组气藏属于致密砂岩气藏范畴,以目前钻井及地震获得的地质资料为基础,结合前人的地质认识,系统总结出该区致密砂岩气藏成藏地质特征:(1)气源充足,源储紧邻;(2)储层普遍致密,存在局部浊沸石溶蚀"甜点";(3)储层致密时间与成藏时间匹配并存在多期充注;(4)存在良好的封盖条件;(5)不整合—断裂—微裂缝空间匹配关系为气运聚提供良好疏导条件;(6)宽缓的斜坡背景下,储层普遍含气,局部富气,气水倒置;(7)气藏内部存在异常压力。基于以上地质特征,解剖确定气藏成藏的主要控制因素,获得关键评价参数,通过关键参数的多条件叠合确定致密砂岩气藏的有利勘探区域。并依据资料实际情况,优选资源丰度类比法、蒙特卡洛随机模拟法及致密砂岩气快速评价方法对有利区气资源量进行估算,该区致密砂岩气资源量约为1 468×10~8m^3。

Gas reservoirs of Permian Jiamuhe Formation in Xinguang area,Jungger Basin are tight sandstone gas reservoirs.Based on present geological data by well and seismic,and previous geological knowledge about this area, the author made a systematic summary about the geological characteristics： （1）abundant source, close distance between source and reservoirs ; （2） tight reservoirs with ＂sweet spots＂ ; （3） the tight time of reservoir is matched with the accumulation time,and the gas charging is multiphased; （4）good capping capability;（5）matched relationship between unconformity, faults and microcracks created good condi- tions for gas migration; （6）located in a wide and gentle slope area, gas-bearing universality, but local rich gas,and the gas water relationship is inverted; （7）abnormal pressure is widely distributed.Based on above geological characteristics, the author confirmed the main controlling factors of reservoir formation, and got the key evaluation parameters, then used these parameters to determine favorable exploration area by mul- tieonditional analysis.Based on the actual data, the author optimized resource abundance analogy method, Monte Carlo stochastic simulation method and the rapid assessment method to estimate gas resources in favorable area,and the gas resources of tight sandstone in this area is about 1 468×10^8m^3.