陕北地区大型三角洲油藏富集规律及勘探技术应用

Oil reservoir enrichment patterns of large delta systems and application of exploration techniques in Shanbei area

陕北地区发育大型三角洲沉积体 ,储集体主要以三角洲分流河道、河口坝沉积为主 ,主砂体厚度大于 15m ,砂体在纵向上可对比追踪 ,平面上复合连片。该储层由于次生浊沸石溶解在低渗透背景上而形成了相对高渗区。形成的三角洲油藏具有含油显示普遍、工业产层多、油气资源丰富的特点 ,具备形成大型油田的物质基础。对该区的石油勘探成果、地质条件及勘探技术的应用进行了综合分析 ,阐述了探明 12亿t规模的石油地质储量的基础及采取的勘探技术措施。

Large delta deposition systems were developed extensively in Shanbei area.The delta distribution channel and the river mouth bar were dominated in Chang 6 period.The main sandstone with over 15 meters in thickness can be correlated vertically and connected as a complex laterally.The relative high-permeability zones were resulted from the dissolution of authigenic laumontite on the low-permeability background.The delta oil reservoirs formed in this area keep the features of universal gas-bearing shows,more commercial oil pays,and richness in petroleum resources.It has the material bases for forming large oilfields.The groundworks for ascertaining 1200 million tons of oil in place and some exploration techniques were described.The petroleum exploration achievements,geological conditions and the exploration techniques applied in the area were summarized.