东海丽水凹陷物源及其对储层物性影响

为确定东海陆架盆地丽水凹陷物源并寻找有利储层发育区，通过碎屑锆石U-Pb定年分析丽水凹陷东、西次洼的物源及源区性质，在此基础上探讨不同物源对砂岩储层物性的影响。经分析，丽水西次洼物源主要来自凹陷西部的闽浙隆起区，以火山岩为主，含少量侵入岩及变质岩；该物源形成的砂岩塑性物质含量较高、岩石抗压性相对较弱，由压实作用造成的孔隙损失量相对较大。丽水东次洼物源主要来自凹陷东部的渔山隆起区，以沉积岩、侵入岩为主要物源；该物源形成的砂岩塑性物质含量较低、岩石抗压性较强，由压实作用造成的孔隙损失量相对较小。研究表明，物源差异对储层物性有较大的影响。

Provenance of sediments and its effects on reservoir physical properties in Lishui Sag,East China Sea Shelf Basin

In order to determine the provenance of sediments and play fairways in Lishui Sag,East China Sea Shelf Basin,we analyzed and characterized the provenances of the sediments in the sub-sags in eastern and western Lishui Sag through detrital zircon U-Pb dating and discussed the influences of different provenances on the physical properties of sandstone reservoirs in the Sag.The results show that sediments in the west sub-sag were mostly sourced from Minzhe Uplift Zone in the western part of the Sag where volcanic rocks are predominant with some intrusive and metamorphic rocks.The sandstone formed by sediments sourced from this provenance has high plastic content and low resistance to compaction,thus porosity loss is relatively largeduring compaction processes.The sediments in the east sub-sag were mostly sourced from Yushan Uplift Zone in the eastern part of the Sag where sedimentary rocks and intrusive rocks are predominant.The sandstone formed by sediments sourced from this provenance has low plastic content and strong resistance to compaction,thus porosity loss is relatively small during compaction.It is suggested that the provenance differences indeed have certain impact upon the physical properties of the reservoirs in the Sag.