首页|珠江口盆地白云凹陷储层成岩特征及中深层储层勘探潜力

珠江口盆地白云凹陷储层成岩特征及中深层储层勘探潜力

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珠江口盆地白云凹陷是深水勘探的重要目标,具有高变地温梯度特征,单井地温梯度高达66.4 ℃/km.高地温场对储层成岩具有重要的控制作用,影响孔隙的演化和孔渗关系的变化趋势;然而,高地温梯度背景下地温梯度对储层质量的影响机理尚不清楚,严重制约了下一步的勘探部署.通过分析研究区始新统—下中新统的岩石样品,采用对比研究的方法,综合分析了深水区地温场、地层温度、岩石学组成和储层演化之间的关系.珠江组和珠海组的渗透率随着埋深和地层温度的增加迅速下降,在现今地温高于140 ℃的情况下,渗透率通常小于1 mD①,砂岩孔隙以次生孔隙为主,孔隙内部充填碳酸盐胶结物和自生黏土矿物;恩平组由于岩石学组分差异而表现出不同的演化特征,即使在孔隙度快速降低的情况下仍能保持较好的渗透率,可高达200 mD,恩平组砂岩为一套粗砂岩,颗粒以石英为主,原生孔隙保存,孔隙结构好,粒间充填少量胶结物,具有良好的孔渗关系.研究认为储层孔隙度、渗透率下降速率不仅受地温场的影响,同时也受砂岩原始组分的控制.
Diagenetic Characteristics of Reservoirs and Middle-Deep Reservoirs Exploration Potential in Baiyun Sag,Pearl River Mouth Basin
Baiyun sag in the Pearl River Mouth basin is an important target for deepwater exploration,which has a highly variable geothermal gradient.The geothermal gradient of a single well is as high as 66.4 ℃/km.The high geothermal field has an important control effect on the diagenesis of the reservoir,affecting the evolution of pores and the changing trend of the relationship between porosity and permeability.However,the influence mechanism of geothermal gradient on reservoir quality under the background of high geothermal gradient is still unclear,which seriously restricts the further exploration deployment.By analyzing rock samples from Eocene to the Early Miocene in the study area,the relationship among genthermal field,formation temperature,petrological composition and reservoir evolution in deepwater area is comprehensively analyzed by means of comparative study.The permeability of Zhujiang Formation and Zhuhai Formation decreases rapidly with the increase of formation temperature and burial depth.When the formation temperature exceeds 140 ℃,the permeability is usually less than 1 mD.The sandstone pores are mainly secondary pores with carbonate cement and authigenic clay minerals inside.However,Enping Formation exhibits different characteristics,maintaining a high permeability up to 200 mD,even with a rapid decrease in porosity.The sandstone of Enping Formation is a set of coarse-grained sandstone,mainly composed of quartz,with preserved primary pores,good pore structure,less intergranular filling with cement,and good porosity-permeability relationship.It could be concluded that the decreasing rate of porosity and permeability in the reservoir was controlled by the geothermal field as well as the primary composition of sandstone.

reservoirdiagenesishigh geothermal fieldreservoir pore evolutionBaiyun sagPearl River Mouth basin

马永坤、徐乐意、孙辉、汪晓萌、李晓艳、周凤娟

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中海石油(中国)有限公司深圳分公司,广东 深圳 518054

中海石油深海开发有限公司,广东 深圳 518054

储层 成岩作用 高地温场 储层孔隙演化 白云凹陷 珠江口盆地

2024

吉林大学学报(地球科学版)
吉林大学

吉林大学学报(地球科学版)

CSTPCD北大核心
影响因子:1.062
ISSN:1671-5888
年,卷(期):2024.54(6)