川西北地区须家河组天然气成藏条件研究
发布时间：2018-12-26 10:08
【摘要】：四川盆地西北地区天然气资源丰富,勘探开发潜力大,其中须家河组近年来取得了巨大的勘探进展,是该地区增储上产的重要层系。然而川西地区的构造复杂,储集类型多样,优质储层主控因素及分布不明确、成藏控制因素待落实,阻碍了该地区须家河组天然气的进一步勘探。本文着重于基础性研究,通过岩心观察、野外露头描述、测井资料分析,结合各种现代测试手段,包括岩心薄片观察、扫描电镜、X衍射以及有机碳含量测定、碳同位素测定、饱和烃轻烃色谱分析等地球化学实验分析,系统地研究了川西北地区须家河沉积、储层特征等成藏条件。川西北地区须家河组分为须一至须五段。须一至须二段为海相沉积,须三段之后为陆相沉积,须家河组沉积时总体为温暖、潮湿的热带、亚热带气候。各层段砂体大面积继承性发育,其中须一段发育礁滩相和三角洲相,礁滩体和三角洲前缘砂体发育;须二段发育潮汐三角洲相,三角洲前缘潮汐水道和潮汐砂坝砂体;须三、须四和须五段发育冲积扇、扇三角洲和湖泊相,三角洲前缘发育重力流水道和河口砂坝砂体。川西北地区须家河组储层以特低孔-超低渗为主,储集空间类型多样,主要为残余原生粒间孔、粒间溶孔、粒内溶孔和裂缝,主要岩石类型为岩屑石英砂岩。总体上发育孔隙型、裂缝-孔隙型和裂缝型三类储层。深部有相对高孔砂岩储层发育,孔隙度8%~11%,最高达13.5%。优质储层形成主要受岩石矿物成分、绿泥石衬边、岩石粒度和分选性、裂缝等因素控制。川西北地区须家河组各段均发育烃源岩,主要产层为须三、须四段,烃源岩有机质丰度总体均较高,且煤有机质类型都为腐殖型,泥质岩有机质类型为腐泥-腐殖型和腐殖型为主。烃源岩Ro值普遍大于1.0%,成熟度总体处于成熟-过成熟阶段。天然气为典型煤成气,具有近源聚集、普遍含气特征。须家河组烃源岩和储集体间互发育的“三明治”结构,使得成熟烃源岩具有面状供烃、近源高效聚集的成藏特征,从不同层段烃源岩生气强度与各层段获气井的关系可以看出,天然气的分布明显与烃源岩的发育程度密切相关。
[Abstract]:The northwest region of Sichuan Basin is rich in natural gas resources and has great potential for exploration and exploitation. The Xujiahe formation has made great progress in exploration in recent years and is an important formation of increasing reservoir and production in this area. However, the complex structure, diverse reservoir types, unclear main controlling factors and distribution of high-quality reservoirs, and reservoir forming control factors in western Sichuan prevent the further exploration of natural gas in Xujiahe formation. This paper focuses on basic research, including core observation, field outcrop description, log data analysis, and combined with various modern testing methods, including core thin slice observation, scanning electron microscope, X-ray diffraction, organic carbon content determination, carbon isotope measurement. Based on the geochemical experiments, such as chromatographic analysis of saturated hydrocarbons, the reservoir forming conditions such as Xujiahe sedimentation and reservoir characteristics in northwestern Sichuan are systematically studied. The Xujiahe formation in northwest Sichuan is divided into one to five sections. The first to second member of Xujiahe formation is marine deposit, and the third member is continental deposit. When Xujiahe formation is deposited, it is warm, humid tropical and subtropical climate. The sand bodies of each formation are inherited in a large area, one of them is the reef beach facies and the delta facies, the reef beach body and the delta front sand body are developed, the second member has developed the tidal delta facies, the delta front tidal channel and the tidal sand bar sand body, and the second member has developed the tidal delta facies, the delta front tidal channel and the tidal bar sand body. The alluvial fans, fan deltas and lacustrine facies are developed in the fourth and fifth members of Xuzhou formation, and gravity flow channels and estuarine bar sandbodies are developed in the front of the delta. The reservoir of Xujiahe formation in northwestern Sichuan is mainly composed of ultra-low porosity and ultra-low permeability, with various reservoir space types, mainly residual primary intergranular pore, intergranular dissolved pore, intragranular dissolved pore and fracture, and the main rock type is lithic quartz sandstone. Generally, there are three types of reservoirs: pore type, fracture-pore type and fracture type. There are relatively high porosity sandstone reservoirs in the deep, with porosity of 8 and 11, the highest being 13.5. The formation of high quality reservoir is mainly controlled by rock mineral composition, chlorite lining, rock granularity and sorting, fracture and so on. The source rocks are developed in each section of Xujiahe formation in northwestern Sichuan, and the main strata are Xu3 and Xu4. The abundance of organic matter in source rocks is generally high, and the types of coal organic matter are humic. The organic matter types of argillaceous rocks are mainly humic-humic and humic-type. The Ro value of the source rocks is generally greater than 1.0, and the maturity of the source rocks is generally at the stage of maturation to overmaturity. Natural gas is a typical coal-formed gas with the characteristics of near source accumulation and general gas bearing. The "sandwich" structure developed between source rocks and reservoir bodies in Xujiahe formation makes mature source rocks have the characteristics of surface hydrocarbon supply and high efficiency accumulation near sources. It can be seen from the relationship between source rock gas generation intensity and gas wells in different layers. The distribution of natural gas is closely related to the development of source rocks.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13
本文编号：2391945
[Abstract]:The northwest region of Sichuan Basin is rich in natural gas resources and has great potential for exploration and exploitation. The Xujiahe formation has made great progress in exploration in recent years and is an important formation of increasing reservoir and production in this area. However, the complex structure, diverse reservoir types, unclear main controlling factors and distribution of high-quality reservoirs, and reservoir forming control factors in western Sichuan prevent the further exploration of natural gas in Xujiahe formation. This paper focuses on basic research, including core observation, field outcrop description, log data analysis, and combined with various modern testing methods, including core thin slice observation, scanning electron microscope, X-ray diffraction, organic carbon content determination, carbon isotope measurement. Based on the geochemical experiments, such as chromatographic analysis of saturated hydrocarbons, the reservoir forming conditions such as Xujiahe sedimentation and reservoir characteristics in northwestern Sichuan are systematically studied. The Xujiahe formation in northwest Sichuan is divided into one to five sections. The first to second member of Xujiahe formation is marine deposit, and the third member is continental deposit. When Xujiahe formation is deposited, it is warm, humid tropical and subtropical climate. The sand bodies of each formation are inherited in a large area, one of them is the reef beach facies and the delta facies, the reef beach body and the delta front sand body are developed, the second member has developed the tidal delta facies, the delta front tidal channel and the tidal sand bar sand body, and the second member has developed the tidal delta facies, the delta front tidal channel and the tidal bar sand body. The alluvial fans, fan deltas and lacustrine facies are developed in the fourth and fifth members of Xuzhou formation, and gravity flow channels and estuarine bar sandbodies are developed in the front of the delta. The reservoir of Xujiahe formation in northwestern Sichuan is mainly composed of ultra-low porosity and ultra-low permeability, with various reservoir space types, mainly residual primary intergranular pore, intergranular dissolved pore, intragranular dissolved pore and fracture, and the main rock type is lithic quartz sandstone. Generally, there are three types of reservoirs: pore type, fracture-pore type and fracture type. There are relatively high porosity sandstone reservoirs in the deep, with porosity of 8 and 11, the highest being 13.5. The formation of high quality reservoir is mainly controlled by rock mineral composition, chlorite lining, rock granularity and sorting, fracture and so on. The source rocks are developed in each section of Xujiahe formation in northwestern Sichuan, and the main strata are Xu3 and Xu4. The abundance of organic matter in source rocks is generally high, and the types of coal organic matter are humic. The organic matter types of argillaceous rocks are mainly humic-humic and humic-type. The Ro value of the source rocks is generally greater than 1.0, and the maturity of the source rocks is generally at the stage of maturation to overmaturity. Natural gas is a typical coal-formed gas with the characteristics of near source accumulation and general gas bearing. The "sandwich" structure developed between source rocks and reservoir bodies in Xujiahe formation makes mature source rocks have the characteristics of surface hydrocarbon supply and high efficiency accumulation near sources. It can be seen from the relationship between source rock gas generation intensity and gas wells in different layers. The distribution of natural gas is closely related to the development of source rocks.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13
【参考文献】
相关期刊论文 前1条
1 王世谦,罗启后,伍大茂;四川盆地中西部上三叠统煤系地层烃源岩的有机岩石学特征[J];矿物岩石;1997年01期
，本文编号：2391945
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