南堡4号构造中深层异常高孔带类型及成因

Types and causes of anomalously high porosity zone in middle and deep reservoir of 4th Structure, Nanpu Depression

应用岩心、普通薄片、铸体薄片、扫描电镜和分析化验等资料,发现南堡4号构造中深层存在异常高孔带,并对异常高孔带的类型及成因进行了分析。研究表明：南堡4号构造在中深层3 800~3 900 m和3 900~4 100 m发育2个异常高孔带,储集空间以原生孔隙为主,原生面孔率百分比大于50%,均为原生孔隙型异常高孔带。分析原生异常高孔带的成因认为,沉积作用为原生异常高孔带的形成提供物质基础,刚性颗粒含量高有效抑制了压实作用,早期油气充注和早期地层超压的发育进一步抑制压实和胶结作用,有效保护了原生孔隙,从而形成了南堡4号构造中深层的原生异常高孔带。

Based on the data analysis of core, ordinary chip, casting lamella and scan electron microscope, anomalously high porosity zone in the middle and deep reservoir is found in the 4th Structure, Nanpu Depression. This essay tries to study the types and causes of anomalously high porosity zone. Study shows that two anomalously high porosity zones exist in the middle and deep reservoirs in 3800-3900 m and 3900-4100 m of the 4th Structure, Nanpu Depression. The reservoir space is mainly of primary pores and the native face rate is more than 50%, which means the anomalously high porosity zones are primary pore zones. The analysis of the causes of anomalously high porosity zones shows that sedimentation is the material base of the primary zones. High rigid particle content effectively restrains the compaction. The early oil and gas charging and early overpressure of reservoir further depress compaction and cementation, which effectively protects the primary pores and form the primary anomalously high porosity zone of the 4th Structure, Nanpu Depression.