摘要
根据岩心观察描述、铸体薄片、岩心分析化验等资料,研究了车西洼陷沙四上亚段低渗透储层孔隙结构特征,探讨了影响低渗透储层物性的主要因素。研究结果表明研究区沙四上亚段储层岩性以细砂岩和粉砂岩为主,平均孔隙度为14.3%,平均渗透率为13.2×10-3μm2,以低渗透砂岩储层为特征,储集空间以粒间溶孔、粒内溶孔和微裂缝为主,储层孔喉半径一般小于6μm。当孔喉半径小于0.24μm,渗透率小于0.4×10-3μm2,排替压力大于1 MPa时,储层含油气性变差。影响沙四上亚段储层物性的主要因素包括孔喉半径、沉积物颗粒大小、溶蚀孔隙和微裂缝的发育情况,以及泥质质量分数和碳酸盐岩质量分数。孔喉半径大的储层沉积物颗粒相对较粗,储层物性相对较好。溶蚀孔隙主要发育在2 000～2 600 m和3 000～3 700 m,溶蚀孔隙的发育能有效改善储层物性。微裂缝主要发育在断裂带附近,可提高储层渗透率5.4～220.1倍。泥质质量分数和碳酸盐岩质量分数的增加使孔隙度减少3%～5%。
Based on the core observation,casting slices and core testing data,the pore structure characteristics of the upper section of 4th member of Shahejie Formation sandstone reservoir in Chexi Sag were researched and the factors affecting the reservoir physical properties were discussed.The results show that fine sandstone and siltstone are the main types of reservoir lithology.The average porosity of the reservoir is 14.3% and the average permeability is 13.2 ×10-3 μm2,which are characterized by low permeability sandstone reservoir.Intergranular dissolved pore,dissolved pore in grain and micro fracture are the main types of reservoir spaces.Pore throat radius is usually less than 6 μm.When the pore throat radius is less than 0.24 μm,the permeability is less than 0.4×10-3 μm2.When the reservoir displacement pressure is more than 1 MPa,the hydrocarbon-bearing property of reservoir becomes worse.The main factors affecting the reservoir physical properties are pore throat radius and sediment particles,development of dissolved pores and micro fracture,shale and carbonate content.The reservoirs with bigger pore throat radius have relatively bigger sediment particles and the reservoir physical property is relatively better.The dissolved pores improve the reservoir property and they are developed in 2,000-2,600 m and in 3,000-3,700 m.Micro fractures are mainly developed near fault zone,which increases the reservoir permeability by 5.4-220.1 times.The content increase of shale and carbonate reduces reservoir porosity by 3%-5%.
出处
《断块油气田》
CAS
北大核心
2010年第5期537-541,共5页
Fault-Block Oil & Gas Field
基金
中石化重点攻关项目"车西洼陷南坡沙三
沙四段沉积与成藏研究"资助
关键词
低渗透砂岩储层
孔喉半径
沉积物颗粒大小
溶蚀孔隙
微裂缝
车西洼陷
渤海湾盆地
sandstone reservoir with low permeability
pore throat radius
size of sediment particles
dissolved pores
micro fracture
Chexi Sag
Bohai Bay Basin.
