渤海南部海域新生代岩浆活动对古近系优质储层的控制作用  

Control of Cenozoic magmatic activity on Paleogene high quality reservoirs in southern Bohai sea

作　　者：牛成民 郭涛 杨波 刘庆顺 杨海风 NIU Chengmin;GUO Tao;YANG Bo;LIU Qingshun;YANG Haifeng(CNOOC China Limited,Tianjin Branch,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司渤海石油研究院,天津300459

出　　处：《中国海上油气》2019年第2期11-19,共9页China Offshore Oil and Gas

基　　金：国土资源部"十三五"全国油气资源评价项目"中海油矿权区油气资源评价(编号:2017YQZYPJ0109)"部分研究成果

摘　　要：近年来在渤海南部海域黄河口凹陷和莱州湾凹陷发现了渤中34-A和垦利6-B两个新生界岩浆岩下的大中型油田,引领了岩浆岩区的勘探热潮。这2个油田虽然岩浆喷发模式类似,但同样是3 000 m深度附近的东营组辫状河三角洲储层,渤中34-A区的储层物性远远优于垦利6-B区。基于储层物性分析、岩心薄片观察、成岩阶段划分,结合岩浆活动及物源体系分析,对研究区古近系储层物性差异成因进行了研究,结果表明:近物源方向的火山喷发活动能够为玄武岩水解富铁镁水介质输送到目标区创造条件,这种弱碱性水介质可以抑制早期长石蚀变、高岭土沉淀,进而有利于原生孔隙的保存;同沉积早期火山喷发形成的桥墩状构架有效支撑了古近系储层粒间孔隙的保存,减缓了塑性火成岩岩屑的变形;新近纪晚期火山活动产生的热液流体加速了成岩阶段演化,形成大量菱铁矿重结晶,对孔隙保存不利。新生代多期岩浆活动对渤海南部海域古近系优质储层控制作用的差异性明显,寻找近物源方向、同沉积早期火山喷发的古近系优质储层发育区,是渤海海域深层岩浆岩发育区的勘探方向。本文研究成果可为渤海湾盆地及其他类似新生界岩浆活动区的优质储层研究提供参考。In recent years,two large and medium-sized oilfields of BZ34-A and KL6-B under the Cenozoic magmatic rocks have been discovered in Huanghekou sag and Laizhouwan sag in the southern Bohai sea,leading the exploration boom in the magmatic area.Although the magmatic eruption patterns in these two oilfields are similar and both are braided river delta reservoirs of Dongying Formation near the depth of 3000 m,the reservoir physical properties of the BZ34-A area are much better than those in KL6-B area.Based on reservoir physical property analysis,core slice observation,diagenesis stage division,magmatic activity and provenance system analysis,the origin of physical property difference of Paleogene reservoirs in the study area is studied.The results show that the volcanic eruption in the near source direction can create favorable conditions for basalt to hydrolyze Fe-rich and Mg-rich water medium and to be transported to the target area.This weak alkaline water medium can inhibit the alteration of feldspar and the precipitation of kaolin in the early stage.Thus,it is beneficial to the preservation of primary pores.The bridge piers formed by volcanic eruptions in the early synsedimentary period effectively supported the preservation of intergranular pores in Paleogene reservoirs and slowed down the deformation of plastic igneous debris.Hydrothermal fluid generated by late Neogene volcanic activity accelerated the diagenetic evolution and formed a large number of siderite recrystallization which is unfavorable for pore preservation.The Cenozoic multi-period magmatic activity has obvious differences in controlling the Paleogene high quality reservoirs in the southern Bohai sea.The exploration direction of deep magmatic rock development area in Bohai sea is to find out the direction of the source of the Paleogene and the developing area of the Paleogene high quality reservoir in the early sedimentary period of volcanic eruption.The results of this paper can be used as a reference for the study of high quality reservoirs in

关 键 词：渤海南部 黄河口凹陷 莱州湾凹陷 新生代岩浆活动 古近系优质储层 原生孔隙 成岩作用 

分 类 号：TE122.2[石油与天然气工程—油气勘探]