Abstract: Detailed examinations of petrography,SEM,X-ray diffraction,electron microprobe,andstable isotope indicate the main diagenetic events in the reservoirs in Jiufetang forrnation,Luxi depression,Authigenetic minerals in the reservoirs are smectite,illite,illite-smectite,chlorite,kaolinite,quartz,albite,zeolite,and carbonate. Diagenetic zones can be dividablehsed on diagenetic events related to temperature. Reservoir porosity in Jiufetang formationis secondary in origin and mainly distributed in the shallow diagenetic zone. Two diageneticmodels regarding the forlnation and distribution of secondary porosity include:(a)the forma-tion of secondary porosity relative to meteoric burial diagenesis;(b)the formation of sec-ondary porosity associated with dehydration and transformation of clay minerals.

Key words: Luxi depression, diagenesis, secondary porosity, clay mineral, reservoir, fan delta

摘要： 在沉积背景研究基础上,采用岩石学薄片、扫描电镜、x-衍射、电子探针和同位素等分析手段,对陆西凹陷九佛堂组储层成岩作用进行了研究.储层成岩矿物主要有蒙脱石、伊利石、伊/蒙混层、绿泥石、高岭石、石英、钠长石、沸石和碳酸盐等.以与地温有关的成岩变化为依据,将本区成岩作用带进行了划分.通过对储层储集空间的研究,提出储层以次生孔隙为主,且次生孔隙主要形成于成岩作用浅带.本区次生孔隙储集砂体的形成机制主要有两种:①与大气水下渗淋滤有关的次生孔隙砂体形成机制,可解释包日温都地区次生孔隙砂体的发育;②与粘土脱水和转化有关的次生孔隙形成机制,可解释马象铺地区次生孔隙储集砂体的形成.

关键词: 陆西凹陷, 成岩作用, 次生孔隙, 粘土矿物, 储层, 扇三角洲