齐家地区高台子油层致密砂岩油藏特征及勘探潜力

CHARACTERISTICS AND EXPORATION POTENTIAL FOR GAOTAIZI TIGHT SANDSTONE OIL RESERVOIRS IN QIJIA AREA

齐家地区高台子油层致密砂岩油藏烃源岩条件好、分布范围广,储层致密、孔喉结构复杂、砂岩普遍含油,原油性质好、油藏压力系数高.致密砂岩储层发育于青山口组二段成熟烃源岩范围内,砂岩与烃源岩呈互层分布,优越的源储配置关系是致密油形成的关键因素.致密油分布受沉积相及物性控制,三角洲前缘亚相的河口坝和远砂坝微相砂体厚度大、物性好,是勘探的主要目标.初步估算齐家地区高台子油层致密砂岩油具有亿吨级资源潜力,具有较好的勘探前景。

The source rocks in Gaotaizi tight sandstone oil reservoirs of Qijia area are characterized by good conditions and wide distribution,and the corresponding reservoirs are tight,the pore-throat structures are complex,the sandstones are generally oil-bearing,the properties of the crude oil are pretty good and the reservoir pressure coefficients are greatly high.The tight sandstone reservoirs are well-developed inside the mature source rocks of Member 2 of Qingshankou Formation and moreover the sandstones are interbedded with the source rocks,the superior allocating relationship between the source rocks and reservoirs is the key factor for the accumulation of the tight oil.The distribution of the tight oil is controlled by the sedimentary facieses and physical properties,the microfacies sandbodies in the delta-front-subfacies river mouth bars and distal bar are the main exploration projects thanks to the thick sandbodies and good physical properties.It is preliminarily evaluated that the total tight sandstone oil resources of Gaotaizi oil reservoirs in Qijia area are beyond 100 million tons,and furthermore possess much better exploration prospects.