镇泾地区延长组长9段储层成岩作用特征

1.西北大学 地质学系,陕西 西安 710069; 2.大陆动力学国家重点实验室,陕西 西安 710069; 3.西南石油大学 地球科学与技术学院,四川 成都 610500

成岩作用; 物性; 长9储层; 镇泾地区

Diagenesis characteristics of Chang 9 reservoir of Yanchang Formation in Zhenjing Area
ZHANG Meng-ting1,2,LI Wen-hou1,2,BAI Jin-li1,2,ZHANG Qian1,2,LI Zong-lin3

(1.Department of Geology,Northwest University,Xi'an 710069,China; 2.State Key Laboratory of Continental Dynamics,Xi'an 710069,China; 3.School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China)

diagenesis; physical properties; Chang 9 reservoir; Zhenjing area

DOI: 10.13800/j.cnki.xakjdxxb.2016.0613

备注

鄂尔多斯盆地镇泾地区长9段是研究区新发现的重点含油层位之一,油气的储集与储层成岩作用有着密切的联系,详细研究该区成岩作用具有重要意义。采用岩石普通薄片、铸体薄片、扫描电镜以及常规物性等分析资料,对长9段的岩石学特征、孔隙特征、储层成岩作用特征等进行了研究。结果 表明研究区储集砂体主要由岩屑长石砂岩构成,含长石砂岩、长石岩屑砂岩; 储层以发育粒间孔和粒内溶孔为主; 经历了复杂的成岩作用,主要为压实作用、胶结作用、交代作用、溶蚀作用等; 现今成岩阶段处于中成岩A期,少量进入了中成岩B期。通过研究不同成岩作用对储集砂岩的孔隙生成和损失的贡献量认为,压实作用使孔隙度减小最多,平均为57.84%,胶结作用使原始孔隙度减少32.3%.溶解作用有效的改善了储层的物性,视溶蚀率为37.98%,交代作用对储层物性影响不大。

Chang 9 which is newly discovered is one of the key oil-bearing strata in zhenjing area of Ordos Basin.The reservoir of oil and gas is closely related to diagenesis,so it is important to study the diagenesis of the study area.Based on the pore casting thin sections,scanning electron microscopy(SEM)and analysis of physical properties,the diagenesis characteristics and the control of diagenesis of Chang 9 reservoir in Zhenjing area,Ordos Basin,are studied in detail.The study area are dominated by lithic arkose sandstones,arkose and feldspathic lithic sandstone.The reservoir rock mainly developed intergranular pores and intragranular dissolved pores,which has undergone complex diagenesis,mainly including compaction,cementation,alteration and corrosion.The reservoir rock are now mainly in middle diagenetic stages of A period-of early B period.After the quantitative evaluation research of pore formation and loss of different diagenesis in sandstone reservoirs,compaction causes the porosity decreased the most,with an average of 57.84%,cementation causes the porosity decreased an average of 32.3%.The dissolution due to 37.98% of the apparent dissolution percentage can effectively improve the physical properties of the reservoir,and the alteration on the physical properties of the reservoir has slight effects.