摘要
近年来,在渤中19-6构造太古界大型变质花岗岩潜山凝析气藏之上的深层(埋深大于3500 m)孔店组砂砾岩储层中首次发现了大量油气,但储层物性差异较大.为了查明深层砂砾岩优质储层的成因,利用铸体薄片、粒度、常规物性、包裹体等化验资料,结合埋藏史分析,对渤海海域渤中19-6构造及围区深层砂砾岩储层物性的差异进行了定量分析,明确了孔店组砂砾岩优质储层发育的主控因素.结果表明:(1)研究区深层孔店组发育扇三角洲砂砾岩储层,埋深分布在3500~4200 m,为深层致密储层,物性较差,以低孔低渗为主,成岩阶段处于中成岩A2-B期,溶蚀孔发育.(2)富钾长石、大气淡水淋滤、有机酸溶蚀、深部热流体、超压和裂缝的叠加是研究区孔店组砂砾岩优质储层发育的主要控制因素.(3)孔店组砂砾岩储层主要经历了大气淡水淋滤增孔‒早成岩期快速压实减孔‒中成岩A1期缓慢减孔以及有机酸、深部热流体大量溶蚀增孔、油气首次充注‒中成岩A2、B期缓慢胶结减孔、溶蚀缝形成和油气大规模充注.(4)但不同构造经历的成岩演化阶段和孔隙演化强度具有明显的差异性,渤中19-6构造孔店组砂砾岩储层经历了早成岩期→中成岩A1期→中成岩A2至B期,对应的孔隙度经历了32.6%→17.3%→12.6%→10.6%的演化过程,其遭受压实和胶结的总减孔量为22.0%,总的减孔率分别为67.6%;而渤中25-1构造砂砾岩储层主要经历了早成岩期→中成岩A1期→中成岩A2期,对应的孔隙度经历了32.8%→19.9%→14.2%→13.2%的演化过程,其遭受压实和胶结的总减孔量为19.6%,总的减孔率分别为59.7%.(5)与渤中19-6构造相比,渤中25-1构造孔店组砂砾岩储层压实作用相对较弱,超压作用更强,溶解作用强,是该构造孔隙度相对较好的主要因素,而粗粒、晚期强压实形成的粒内溶蚀孔‒缝是渤中19-6构造砂砾岩储层渗透率相对较高的主要因素.
In recent years,a large amount of oil and gas was discovered for the first time above the Archean large metamorphic granite buried hill condensate gas reservoir in the Bozhong 19-6 structure in the deep(buried depth greater than 3500 m)Kongdian Formation glutenite reservoir.But it is characterized with larger reservoir difference.In order to identify the causes of deep conglomerate reservoir quality,using analyses of thin section casting and test data,particle size,conventional physical properties,such as inclusion,combined with burial history analysis,quantitative analysis of the physical properties of deep glutenite reservoirs in Bozhong 19-6 and its surroundings of the Bohai Sea was carried out,and the main controlling factors for the development of high-quality glutenite reservoirs in the Kongdian Formation were clarified.It is found that:(1)The deep Kongdian Formation in the study area has developed fan delta glutenite reservoirs with a buried depth greater than 3500-4200 m.It is a deep glutenite reservoir with poor physical properties,mainly low porosity and low permeability,and the diagenesis stage is in the middle diagenesis from A2 to B stage,and dissolution pores are developed.(2)Potassium-rich feldspar framework particles,atmospheric fresh water leaching,organic acid dissolution,overpressure and crack are the main controlling factors for the development of highquality glutenite reservoirs in the Kongdian Formation in the study area.(3)The Kongdian Formation glutenite reservoirs have mainly experienced atmospheric freshwater enhancement-early diagenesis long-term,rapid burial,rapid compaction-reductionmedium diagenesis A1 mid-to-long-term,rapid burial,slow compaction-reduction,organic acid and ultra pressure massive dissolution to increase pores,first filling of oil and gas-mid-diagenetic A2 or B period,short-term,rapid burial,slow cementation,pore reduction,(or formation of corrosion cracks)and large-scale oil and gas filling.(4)However,the diagenetic evolution stages and pore evolution strength experi
作者
庞小军
杜晓峰
王冠民
王清斌
张参
Pang Xiaojun;Du Xiaofeng;Wang Guanmin;Wang Qingbin;Zhang Can(School of Geosciences,China University of Petroleum(East China),Qingdao 266580,China;Tianjin Branch of China National Oil Corporation Limited,Tianjin 300459,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2023年第11期4153-4174,共22页
Earth Science
基金
“十三五”国家科技重大专项(No.2016ZX05024⁃003)
中海油科技项目(No.ZZKY⁃2020⁃TJ⁃03).
关键词
优质储层
孔隙定量演化
砂砾岩
成岩作用
孔店组
渤中19⁃6构造
渤海海域
油气地质
deep high⁃quality reservoir
quantitative evolution of pore
glutenite
diagenesis
Kongdian Formation
Bozhong 19⁃6 structure
Bohai Sea area
petroleum geology
