【作者】 马在平；

【导师】 廖立兵；

【作者基本信息】 中国地质大学（北京） ， 矿物学岩石学矿床学， 2005， 博士

【摘要】 潍北凹陷北部洼陷带天然气资源较丰富,但是,迄今为止,勘探效果并不理想。为了了解储层性质在埋藏过程中的变化情况,为寻找有利储层服务,本论文在收集整理前人相关研究工作资料的基础上,通过岩心观察、取样和室内分析测试,对该地区孔店组碎屑岩储层成岩作用进行了研究并得出以下几点结论: 1 孔店组碎屑岩储层在埋藏成岩过程中发生了压实(压溶)、碳酸盐胶结和交代、硅质胶结、粘土矿物(高岭石、伊蒙间层矿物、绿泥石等)胶结和转变、长石次生加大、黄铁矿胶结、碎屑颗粒和碳酸盐胶结物溶解、粘土杂基和碳酸盐胶结物重结晶等成岩作用;主要成岩作用开始发生的先后序列为:压实作用、方解石胶结→碎屑石英次生加大和粒间微粒石英形成→铁方解石胶结→铁白云石胶结;原始沉积物成分和沉积相、埋深改变引起的地温和压力变化、地层水酸碱度等化学性质特点是影响成岩作用的主要因素。各项成岩强度指标显示北部洼陷带孔店组碎屑岩储层因埋深不同而处于早成岩B 期至晚成岩B 期。2 孔店组碎屑岩储层在埋藏成岩过程中形成的成岩矿物有方解石、铁方解石、铁白云石、石英、高岭石、R0至R3型伊蒙间层矿物、铁斜绿泥石(辉绿泥石)、长石、黄铁矿等。随着成岩强度加大,新形成的碳酸盐胶结矿物中Fe、Mg 含量逐渐升高;绿泥石中Fe 和AlⅣ含量逐渐升高,Si 含量逐渐降低;伊蒙间层矿物的结构有序度整体上逐渐增加。早成岩期碳酸盐胶结物与晚成岩期碳酸盐胶结物的成岩物质来源有所不同。3 研究区古地温梯度高于现今地温梯度。4 孔店组碎屑岩储层因成岩作用强度变化而在垂向上(由浅到深)出现从常规储层到致密储层的有序性递变;致密储层出现的深度大约在埋深3000m 以下。5 储层致密化主要受压实和碳酸盐胶结作用控制。埋深约2800m 以上,压实作用的影响较显著;埋深2800m 以下,碳酸盐胶结作用的影响相对较强。6 孔店组碎屑岩储层的储集空间类型可分为粒间孔、粒内孔、填隙物内孔和裂缝。致密砂岩储层内孔隙普遍微细,而且,由于成岩强度高,岩性脆,易因构造作用形成裂缝。更多还原

【Abstract】 Natural gas is fairly rich in the northern sag of Weibei depression. It has not been well developed until now. On the basis of researches in the past, this dissertation studies diagenesis of the clastic reservoir of Kongdian formation by describing drilling cores, taking and analyzing rock samples in order to understand how the characters of reservoir change during burial process and help to find profitable reservoir. The following conclusions are reached after the study: 1 Diagenetic events occurred in the clastic reservoir rocks during burial diagenesis include compaction and pressure solution, cementation and replacement of carbonate, cementation of quartz, cementation and transition of kaolinite, illite/smectite mixed-layer clay minerals and chlorite, overgrowth of playgioclase, cementation of pyrite and recrystallization of carbonate cements and clay minerals in the matrix. The main diagenetic events such as compaction, cementation of calcite, quartz, ferroan calcite, ferroan dolomite started successively.The main factors affecting diagenesis are the original components of sediments and sedimentary facies, changes of geotemperature and geopressure with depth increasing, pH values and other chemical characters of formation water. The clastic reservoir of Kongdian formation in the sag are in different diagenetic periods, from period B of early diagenetic stage to period B of late diagenetic stage, according to the depth. 2 Diagenetic minerals formed during burial diagenesis include calcite, ferroan calcite, ferroan dolomite, quartz, kaolinite, R0I/S, R1I/S, R3I/S, diabantite, plagioclase and pyrite. As diagenetic intensity increased, the Fe, Mg contents of carbonate cements and Fe, AlⅣcontents of diabansite increased, the Si content of diabansite decreased and ilite/smectite mixed-layer mineral became more ordered. Origin of the material needed for formation of carbonate cements of the early and late diagenetic stages are different. 3 The paleogeothermal gradiant values are greater than that of today. 4 As diagenetic intensity increased with increasing depth, the reservoir changed from the conventional type to the tight one at 3000m in depth. 5 The main diagenetic events lealing to the reservoir becoming tight include compaction and cementation of carbonate. The porosity and permeability of the reservoir were more notably influnced by compaction above 2800m in depth, and cementation of carbonate became the leading role in the deeper place. 6 Pore types of the reservoir include fissures, intergranular pore, innergranular pore and that among interstitial materials. Pore of reservoir is universally very small. Fissures were caused by tectonic movements as the reservoir became more fragile with diagenetic intensity increased.更多还原