摘要
桂中坳陷泥盆纪生物礁滩发育,桂中1井钻探证实该区存在优质生物礁灰岩和白云岩储层。野外露头、显微照片和扫描电镜等分析测试手段表明,该区泥盆纪生物礁储集空间主要包括孔隙、裂缝和溶洞。孔隙类型有粒内溶孔、骨架孔、粒间孔、溶孔、缝合线伴生溶孔等,以晶间溶孔、晶间孔及非组构控制的溶蚀孔、洞、缝为主,储层类型主要为裂缝型、裂缝-孔隙型和孔隙型。沉积环境、成岩作用及构造裂缝控制有利储层的发育,现今储集空间以埋藏溶蚀孔隙和保留下来的残余孔、洞、缝为主。地球化学和成岩作用研究表明,储层孔隙演化与油气充注密切相关,可能发生两期油气充注。储层焦沥青的形成主要是由于地层深埋造成原油热裂解。因此,该区油气勘探应以原油裂解天然气为主,寻找具有保存条件的岩性体。
Devonian reef is developed in the Guizhong depression,and drilling data of well GZ1 support the opinion that high quality biolithite and dolomite reservoirs do exist in the Guizhong depression.Outcrops,micrographs and scanning electronic microscope analyses show that reservoir space is composed of pores,fissures and solution hollows.The interstices include such types as intragranular corroded hollows,frame pores,inter granular pores,corroded hollows and corroded hollows associated with stylolite,with the intercrystalline pores,intercrystalline corroded hollows and corroded pores as well as hollow fissures controlled by nonfabric materials being the main types.It is suggested that the reservoir types can be classified into fissure type,fissure pore type and pore type.The depositional environment,diagenesis and tectoclase controlled the development of the beneficial reservoir.Nowadays reservoir space is mainly made up of burial emposieus and remaining pores,fissures and solution hollows.A study of diagenesis and geochemistry indicates that the porosity evolution was related to the oil accumulation,and that two stages of processes of oil reservoir formation might have occurred.The solid bitumen（or destruction） of the reservoir was related to thermal evolution of the oil due to the subsidence.It is therefore held that the exploration should be mainly concentrated on the oil-cracked gas,with the attention paid to the study of reservation conditions of the rocks.
出处
《中国地质》
CAS
CSCD
北大核心
2011年第1期170-179,共10页
Geology in China
基金
全国油气资源战略选区调查与评价(XQ-2007-01)资助
关键词
桂中坳陷
泥盆纪
生物礁
储层特征
孔隙演化
储层沥青
Guizhong depression
Devonian
reef
feature of reservoir
porosity evolution
solid bitumen
