柴达木盆地阿尔金山前东坪—牛东斜坡带天然气成藏条件

The Gas Accumulation Conditions of Dongping-Niudong Slope Area in Front of Aerjin Mountain of Qaidam Basin

柴达木盆地阿尔金山前东坪—牛东斜坡带早期勘探程度与认识程度均比较低,勘探没有取得突破。近2年在寻找源外大型斜坡岩性油气藏地质新认识的指导下,通过加强斜坡带岩性气藏成藏条件综合分析与评价,认为东坪—牛东斜坡带紧临侏罗系大型生烃凹陷,具有多套目的层系、有利储盖组合、持续发育的古隆起(古斜坡)、区域性不整合、油气疏导断裂等有利成藏条件,目前在低断隆部位的东坪1井基岩风化壳及路乐河组(E1+2)获得勘探突破,在高断阶部位的东坪3井下干柴沟组(E3)也获得工业气流,在牛东鼻隆牛1井侏罗系同样获得高产油气流,展示出整个东坪—牛东斜坡带天然气成藏条件优越,具有广阔的勘探前景。

The level of exploration and geological understanding of Dongping-Niudong slope area,which is in front of Aerjin Mountain of Qaidam Basin,was poor in early period.Recently,under the guidance of the new exploration theory of looking for large lithologic reservoirs,which are outside the sources,in slope areas,we strengthened comprehensive analysis and evaluation of the lithologic gas accumulation conditions in the slope areas.The result showed that the accumulation conditions in Dongping-Niudong slope were favorable,such as large distribution area of source rocks,multiple sets of target layers department,the favorable reservoir-cap combination,the continuing development of palaeohigh（ancient slopes）,regional unconformity,divert fractures for oil and gas and so on.Now,we have achieved great exploration breakthrough in the weathering crust and Lulehe Formation（E1＋2）of Well Dongping 1,which located in low faulted uplift part,industrial gas in lower Ganchaigou Formation（E3）of the Well Dongping 3,which located in high fault terrace part,high-yield oil and gas flow in the Jurassic of well Niu 1,which located in Niudong nose uplift.These findings show that the natural gas accumulation condition in the whole Dongping-Niudong slope is advantageous and this area has broad prospects of exploration.