银额盆地路井凹陷下白垩统巴一段储层特征及其影响因素

RESERVOIR CHARACTERISTICS AND ITS INFLUENCING FACTORS IN THE LOWER CRETA CEOUS IN LUJINGSAG,YIN'E BASIN

近年来,银额盆地路井凹陷的油气勘探取得了一些成果,但其勘探程度低且地质条件复杂,储层特征及其影响因素尚不明确。本文从储层岩石学特征着手,运用常规物性分析、岩石薄片及铸体薄片等资料分析了储层特征,从沉积相、压实作用、岩屑组分和粒度等方面探讨了储层的影响因素。巴一段储层岩性主要为岩屑砂岩和长石岩屑砂岩,砂岩多呈粗粒砂状结构,磨圆度差到中等,分选中到差。胶结类型主要为孔隙式胶结,成分成熟度较低。平均孔隙度5.2%,平均渗透率0.58×10^-3μm^2。储层孔隙类型主要有粒间孔和粒间溶孔,次生孔隙构成较主要的储集空间。储集层主要分布在扇三角洲前缘。储层物性随着深度的增加而变差,但局部存在高渗带,可能与酸溶作用有关,随着勘探的进一步深入,需要进一步研究。

In recent years,oil and gas exploration in the Lujing Sag of Yin’e Basin has achieved some results,but however,its exploration level is low and its geological conditions are complex,and reservoir characteristics and its influencing factors are still unclear.Starting from the petrophysical characteristics of reservoirs,this paper analyzes the reservoir characteristics by using conventional physical property analysis,rock flakes and cast thin sections,and discusses the influencing factors of reservoirs from the aspects of sedimentary facies and compaction.The lithology of the reservoir is mainly lithic sandstone and feldspar lithic sandstone.The sandstone is mostly coarse-grained sand-like structure,and the roundness is moderate to moderate.The type of cementation is mainly pore cementation with low compositional maturity.The average porosity is 5.2%and the average permeability is 0.58 mD.The pore types of the reservoir mainly include intergranular pores and intergranular dissolved pores,and secondary pores constitute the main reservoir space.The reservoir is mainly distributed in the fan delta front,and the physical properties of the reservoir deteriorate with the increase of depth,but there is a local high-permeability zone,which is related to the Acid dissolution,as exploration progresses further,further research is needed.