鄂尔多斯盆地华庆地区长8油藏局部油水分布复杂成因分析

Causes for complex oil and water distribution in parts of Chang 8 reservoir,Huaqing area,Ordos Basin

华庆地区位于长7源岩的发育区,油源充足,成藏条件有利,区内也发现许多高产富集区,但该区油的分布不均,局部高孔高渗带测试产大水,如白241等井。根据大量钻测井、试油试采以及储层荧光等分析资料,系统地研究了华庆地区长8油藏局部油水分布复杂的原因,指出长8油藏局部高孔高渗带出水的原因是长7源岩与储层之间存在泥岩隔层,它阻碍源岩生成的油往下运移到长8储层,源岩与储层之间的输导层控制了该区长8储层的含油性。该认识为研究区下一步的勘探和评价提供了可靠的地质依据。

Huaqing area locates at the development area of Chang 7 source rocks,where oil supplies are sufficient and reservoir formation conditions are favorable.Many petroliferous zones have been found;however,the distribution of oil in the area is unbalanced.In some local regions with high porosity and permeability,a large amount of water has been found in well testing,for example,in well Bai 241,etc.Based in the data of well drilling,logging,testing and reservoir fluorescence,it is analyzed in this paper the causes for the complex oil and water distribution in parts of Chang 8 reservoir,Huaqing area,the Ordos Basin.It is pointed out that mudstone layers between the Chang 7 source rocks and the Chang 8 reservoir block the migration of oil generated from the Chang 7 source rocks into the Chang 8 reservoir.The carrier bed between source rocks and reservoir controls the potentials of Chang 8 reservoir.These conclusions provide geological basis for further exploration and evaluation in the study area.