摘要
基于岩心和薄片观察、矿物流体包裹体测温、微量元素分析、裂缝充填物碳氧同位素分析、常规物性分析等技术手段,分析渤海湾盆地东营凹陷西部下古生界热液流体活动证据,定量评价热液流体对不同类型碳酸盐岩储集层溶蚀改造程度,并对储集层有效裂缝纵向分布规律进行了研究。研究区热液溶蚀的判识标志为发育的典型热液矿物组合,如萤石-硬石膏-自生石英组合等,与热液相关的裂缝充填物中包裹体均一温度高达150～210℃,另外热液溶蚀区域碳酸盐岩表现出高Fe O、高Si O2、高Mn O、低Na_2O含量的特征。热液流体溶蚀作用不仅可产生新的萤石矿物,而且溶蚀形成了大量的孔、微孔、小缝及微缝,改善了碳酸盐岩储集层物性。热液流体溶蚀围岩的同时会携带碳酸盐物质在构造裂缝中淀积成方解石等裂缝充填物,由于热液沿断裂上升过程中流速和温度逐渐降低,导致下古生界不同层段中发生的溶蚀强度和充填程度差异明显,其中凤山组和冶里组—亮甲山组构造裂缝充填程度低、溶蚀孔缝发育,马家沟组构造裂缝充填程度高、溶蚀孔缝相对不发育。
By integrating the analyses of core samples, thin sections, homogenization temperature measurement of inclusions, stable isotopic compositions of carbon oxygen, trace element composition, and conventional physical properties, this research identifies the evidence of Lower Paleozoic hydrothermal fluid activity in the western Dongying sag of Bohai Bay Basin, quantitatively evaluates the hydrothermal dissolution strength in various carbonate reservoirs, and analyzes the longitudinal distribution of effective fractures in reservoirs. The markers of hydrothermal dissolution in the study area include the typical hydrothermal mineral combinations such as fluorite-anhydrite-authigenic quartz combination, the homogenization temperature of inclusions in fracture fillings related to hydrothermal fluid of up to 150 ℃-210 ℃, and the high Fe O, high Si O_2, high Mn O and low Na_2 O features of carbonate in hydrothermal fluid karst area. Dissolution of hydrothermal fluid can produce not only new fluorite mineral, but also many pores, micropores, small fractures and micro-fractures, which significantly improve the quality of carbonate reservoirs. During the process of hydrothermal fluid dissolution, calcite precipitated and filled structural fractures as the hydrothermal fluid dissolved host rock. As the hydrothermal fluid went up along faults, its velocity and temperature dropped gradually, the intensity of dissolution and calcite filling differ significantly in different formations of the Lower Paleozoic, for example, the Fengshan and Yeli-Liangjiashan Formations have low fracture filling degree and highly developed dissolved fractures and pores, whereas the Majiagou Formation has high fracture filling degree and poorly developed dissolved fractures and pores.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2016年第3期359-366,共8页
Petroleum Exploration and Development
基金
国家油气科技重大专项"渤海湾盆地精细勘探关键技术"项目下属课题三"济阳坳陷油气富集机制与增储领域"(2011ZX05006-003)
关键词
碳酸盐岩
储集层
热液流体
溶蚀改造
渤海湾盆地
东营凹陷
下古生界
定量评价
carbonate
reservoir
hydrothermal fluid
dissolution
Bohai Bay Basin
Dongying sag
Lower Paleozoic
quantitative eveluation
