Characteristics and hydrocarbon generation and expulsion potential of Chang7 shale oil source rocks in Wuqi Area,Ordos Basin
At present,the primary layers produced in Wuqi Area are the lower combination of Jurassic Yan'an Formation(Yan7-Yan10 layers)and the upper combination of Triassic Yanchang Formation(Chang4+5 layers and Chang6 layer).It is urgent to find new replacement layers and replacement energy to meet the strategic goal of sustained,efficient and stable production of the oilfield.The shale oil of Chang7 layer of the Triassic Yanchang Formation as a new replacement layer for Wuqi Oil Production Plant has great exploration and development value.To study the characteristics and exploration potential area of Chang7 shale oil source rock,core analysis,logging curve research,rock pyrolysis analysis,microscopic maceral analysis,vitrinite reflectance(Ro)test,and hydrocarbon generation and expulsion potential calculation were carried out.The results show that the abundance of Chang7 source rocks is generally high,and the tottal organic carbon(TOC)mainly ranges from 0.49％to 41.02％.The organic matters of Chang7 layer are primarily type Ⅰ and type Ⅱ,with strong oil generation capacity.The Ro shows that the source rocks of Wuqi Area are in the mature stage and dominated by oil generation.Most sample Ro range from 0.50％to 1.15％,and the hydrocarbon generation intensity of Chang7 hydrocarbon source ranges from 200× 104 t/km2 to 600 ×104 t/km2,hydrocarbon expulsion intensity mainly ranges from 200 × 104 t/km2 to 300 × 104 t/km2.Based on the thickness of source rocks and the intensity of hydrocarbon generation and expulsion in Wuqi Area,the shale oil exploration potential in Chang7 layer was divided into three categories:Ⅰ,Ⅱ and Ⅲ,the results of exploration drilling and production testing of well Wuyeping1 show that the source rock exploration potential area is a favorable shale oil development layer series and replacement layer.The results will point out the direction for the next exploration and development of shale oil in Wuqi Area.
万方数据
维普
