苏里格气田东南部碳酸盐岩储层特征及分类评价

(1.低渗透油气田勘探开发工程试验室,陕西 西安 710018; 2.中国石油长庆油田公司勘探开发研究院,陕西 西安 710018; 3.西北大学 大陆动力学国家重点实验室; 陕西 西安 710069)

桃2区块; 储集岩类型; 储集空间类型; 储层分类评价; 物性特征

Characteristics and classification of carbonate reservoir in southeastern SuligeGas field
HOU Ke-feng1,2,LI Fu-ping1,2,LUO Chun-you1,2,ZHANG Chun-yang1,2,YU Chun-yong3,REN Zhan-li3,MA Qian3

(1.National Engineering Laboratory for Exploration and Development of Low-Permeability Oil & Gas Fields Xi'an 710018,China; 2.Research Institute of Exploration and Development,PetroChinaChangqing Oilfield Company,Xi'an 710018,China; 3.State Key Laboratory for Continental Dynamics,Northwest University,Xi'an 710069,China)

Tao 2 area; reservoir rock type; reservoir space type; reservoir classification evaluation; physical properties characteristics

DOI: 10.13800/j.cnki.xakjdxxb.2019.0214

备注

通过对岩心薄片、铸体薄片的观察以及压汞测试等技术手段,对研究区奥陶系马家沟组马五1+2和马五14亚段储层储集岩主要类型、储集空间类型、储集岩物性三方面进行了综合研究,并结合研究区碳酸盐岩储集岩孔洞缝的发育程度和组合形式、毛细管压力曲线特征、含气饱和度、有效厚度及残丘发育程度等多方面参数对储层进行了归类与划分,发现桃2区块的溶蚀孔洞状白云岩、泥—粉晶白云岩、颗粒白云岩及角砾状白云岩是储集岩的主要类型; 储集空间类型主要以晶间孔、晶间溶孔、溶洞为主,膏膜孔和微裂缝次之; 研究区碳酸盐岩储层可划分为Ⅰ类(好)、Ⅱ类(较好)、Ⅲ类(中等)、Ⅳ类(非或差)四种类型,其中马五31和马五14储层较马五21和马五22好,Ⅰ类储层主要发育于马五31和马五14亚段中,Ⅱ类储层在各亚段小层中均有分布,马五1+2和马五14亚段则主要发育Ⅳ和Ⅲ类储层。结果 表明:研究区储集岩物性较差,平均孔隙度为2.86%,平均渗透率为0.358 4 mD,孔隙度与渗透率之间不存在正相关关系,总体表现为非均质性较强,且低孔、低渗的特征。

The reservoir rock types,reservoir space types and reservoir rock property in Ordovician Majiagou formation M51+2 and M514 formation was studied by the observation of the core chip,the casting thin sections,mercury injection test and other technical means.According to the development degree of pore-seams,the combination of pore-seams,the characteristics of capillary pressure curves,gas saturation,effective thickness and the degree of residual hillock development in the carbonate reservoir rocks in the study area,the reservoirs are classified and divided into categories.It is pointed that the types of reservoir rocks in Tao 2 area mainly include dissolved cave-shaped dolomite,mud-powdered dolomite,particulate dolomite and brecciated dolomite; the storage space type mainly consists of intergranular pores,intercrystalline pores and karst caves,the paste pores as well as micro-cracks are secondary.The carbonate reservoirs can be divided into four types which are ClassⅠ(good),ClassⅡ(better),ClassⅢ(medium),ClassⅣ(worse).Among them,M531and M514 reservoirs are superior than M521 and M522 reservoirs,ClassⅠreservoirs are mainly distributed in M531 and M514 reservoirs; Class Ⅱ reservoirs are distributed in all reservoirs; M51+2 and M514 sub-reservoirs are mainly Class Ⅳ and Class Ⅲreservoirs.The results indicate that the reservoir rock property in the study area is poor,the average porosity is 2.86%,and the mean permeability is 0.358 4 mD,and there is no positive correlation between porosity and permeability.The overall is characterized by strong heterogeneity,low porosity and low permeability.