沥青充填对储集层储集性能的影响——以准噶尔盆地三台——北三台为例

Impact of Pack Bitumen on Reservoir Quality——An example from Santai-North Santai in Junggar basin

在三台—北三台地区三叠系和侏罗系储集层中发现大量高密度的稠油和沥青,它们充填于储集层的孔隙中,占据了大孔隙,降低了孔隙连通率,使后期生成的原油难以进入孔隙,难以形成规模较大和产量较高的油藏。有机溶剂抽提前后的物性对比实验表明,沥青对储集层物性有很大影响,9个样品的孔隙度测定值最大增加21.5%,平均增加约13.4%,7个样品的渗透率测定值最大增加121.50×10-3μm2,平均增加约31.99×10-3μm2.指出今后寻找高产油层,除考虑构造因素外,还应结合沉积相和储集层的研究成果,尽量避开含沥青较多的储集层。

A large amount of bitumen and heavy oil with high density are found in the Triassic and Jurassic reservoirs in Santai-North Santai area in eastern Junggar basin. They filled into the reservoir pores, occupied the megapores, reduced the porous connection rate, caused the post-generating crude oil to enter the pores with difficulty, hence it is difficult to form larger-scale and higher-yielding oil reservoir. The reservoir property contrast between before and after the organic solvent extraction indicates that the porosity of 9 samples adds to 21.5%, averaging about 13.4%; the permeability of 7 samples adds to 121.50×10^-3μm2, averaging about 31.99×10^-3μm2. It is pointed out that it should keep away from the reservoir with high amount of bitumen as far as possible to find high-yielding oil reservoirs in the future, in addition to considering structural factors, integrated with sedimentary facies and reservoir research results.