论文部分内容阅读
歧口凹陷沙一下亚段白云岩分布广泛,白云岩可以发育物性良好的储层。根据钻井岩心、地球化学特征、扫描电镜、电子探针及物性资料,确定了该套地层白云岩储层的主要岩石类型及储集空间类型:岩石类型可分为微晶白云岩、泥晶白云岩、砂质云岩、灰质云岩和云质灰岩;储集空间有晶间孔、粒间孔、溶蚀孔、构造缝、溶蚀缝等,主要以次生孔隙和裂缝为主。微晶白云岩储集物性较好,主要为晶间孔、粒间孔及裂缝,为较好的储层。分析了目的层白云岩储层的主要成岩作用及期次,主要有胶结作用、压实、压溶作用、白云岩化作用、溶蚀作用等。明确了改善及破坏白云岩储集性能的成岩作用类型,其中对储集性产生积极影响的有溶蚀作用、白云岩化作用,消极影响的有压实、压溶作用、胶结作用。建立了歧口凹陷沙一下亚段白云岩化作用影响储层物性模式,稀土元素 Eu 异常特征揭示了本区白云岩化作用的两种成因环境: 准同生期的回流渗透白云岩化作用和成岩期的埋藏白云岩化作用,通常准同生期的回流渗透白云岩经过深部热液流体的改造,发生埋藏白云岩化作用,多见于裂缝发育区,后者较前者对白云岩储层的改善作用更为明显。
The dolomites in the sub-sand sub-sand of the Qikou sag are widely distributed, and the dolomites can develop reservoirs with good physical properties. According to drilling core, geochemical characteristics, scanning electron microscopy, electron probe and physical data, the main rock types and reservoir space types of dolomite reservoirs in the set of strata are determined: the rock types can be divided into microcrystalline dolomite, Rock, sandy dolomite, limestone dolomite and cloud limestone. There are intergranular pores, intergranular pores, dissolved pores, structural seams and dissolution seams in the reservoir space, mainly taking secondary pores and fissures as the main reservoirs. The microcrystalline dolomite has good reservoir properties, mainly intergranular pores, intergranular pores and fractures, and is a good reservoir. The main diagenesis and period of dolomite reservoirs in the target layer are analyzed, mainly including cementation, compaction, pressure solution, dolomitization and dissolution. The type of diagenesis is defined to improve and destroy dolomite reservoir performance. Among these types of diagenesis, there are dissolution, dolomitization and negative effects of compaction, pressure solution and cementation. The dolomitization of the sub-subsurface sand in the Qikou Depression has the effect on the physical property model of the reservoirs. The characteristics of the Eu anomalies reveal the two genetic environments for the dolomitization in this area: dolomitization by recirculation, quasi- Burial dolomitization in diagenetic stage, usually quasi-synoptic return infiltration dolomite through deep hydrothermal fluid transformation, burial dolomitization occurs, more common in the area of fracture development, the latter than the former on the dolomite reservoir Improve the role of more obvious.