鄂尔多斯盆地延安组小油藏治理对策研究——以志丹油田2067井区为例

Study on the Countermeasures of Small Reservoir Management of Yan'an Formation in Ordos Basin ——By Taking Wellblock 2067 of Zhidan Oilfield for Example

鄂尔多斯盆地下侏罗统延安组油藏是盆地内主要的勘探开发目的层，在盆地分布范围很广，从盆地西缘的断裂带附近到陕西省安塞县以东均有发现。延安组油藏埋藏浅，成藏规模小，砂体与构造的良好匹配是成藏的控制因素。这类油藏在志丹油田数量众多（古甘陕古河道两侧附近），由于其埋藏浅、物性相对较好，边底水能量较为充足，利用边底水天然能量开发，采收率可以达到20％～30％。通过对志丹油田延安组小油藏地质及开发特征的认识，分析了一个小油藏2067井区延安组延9油层组2砂层剩余油分布特征及开发潜力，提出了综合治理对策，利用水平井产能预测公式计算得出，水平井稳产期后日产油n．4t，2067井区日产油可达30t，预测采收率可达25．5％，为志丹油田众多延安组小油藏的开发提供借鉴。

The reservoir of Yan'an Formation of early Jurassic in Ordos Basin was the main target zone for exploration,it was widely distributed in the basin,it was found out from the fracture in the western margin near the basin to the east of Ansai County of Shaanxi Province.The reservoir of Yan'an Formation was shallowly buried,and it was small scale,the good matching between the sand body and the structure was the controlling factor.There were many such reservoirs in Zhidan Oilfield(near the both sides of ancient Gansu-Shaanxi River),due to its shallow burial,its physical property was relatively good,edge and bottom water energy was more sufficient,the edge and bottom water energy was used for development,its recovery ratio was as high as 20% ~ 30%.Through the understanding of small reservoir and geologic and development characteristics in Yan'an Formation,the remaining oil distribution and development potential in the 2nd sand layer of Reservoir Y9 of Wellblock 2067 are analyzed,the countermeasures for its management are proposed.The calculation using productivity formula for horizontal wells indicates that the daily oil production is 11.4tin the stabilized period of horizontal wells,in the Wellblock 2067 daily oil production can be as high as 30 t,the predicted oil recovery can be 25.5%,it provides reference for the development of small reservoirs in Yan'an Formation of the oilfield.