东营凹陷古近系储层碳酸盐胶结物分布特征及主控因素

碳酸盐胶结物是东营凹陷砂岩储层的主要胶结物.东营凹陷中的碳酸盐胶结物在纵向上随着埋藏深度的增加,含量具有逐渐增高的趋势,而且厚度较大的含碳酸盐胶结物砂层在层位上主要分布于沙三段,其次分布于沙一段和沙二段,在沙四段钙质砂岩层的分布仅出现于凹陷周边的少许地区.东营凹陷北部陡坡带、中部中央隆起带和南部斜坡带碳酸盐胶结物的含量存在较大的差异:北部陡坡带碳酸盐胶结物含量较南部斜坡带大,而且在相同埋藏深度条件下,北部和南部都比中部的碳酸盐含量要高;在断裂构造带,碳酸盐含量分布分散,含量范围跨度大,而在洼陷带分布深度一般比较集中,含量范围跨度小.碳酸盐胶结物砂岩层发育的有利相带为近岸水下扇、水下冲积扇、深水浊积扇等分选较差的沉积相;而且碳酸盐总体表现为在粒度粗的砂岩中含量较高.在相同埋深条件下,砂岩层的厚度越小,碳酸盐胶结作用越强.当砂岩层围岩为碳酸盐岩或厚的泥岩时,在砂岩层内部易形成高碳酸盐含量、胶结作用强烈的含碳酸盐胶结物.

Distribution Characteristics and Main Controlling Factors of Carbonate Cements in the Paleogene Reservoirs in Dongying Depression

Carbonate cementation is the main type of cementation of sandstone reservoir of Dongying depression.Studies suggest that content of carbonate cementation gradually increases with the burial depth in Dongying depression.The relatively thick sand layer with carbonate cements is mainly distributed in Es3,followed by Es1 and Es2.Calcareous sandstones in Es4 are only seen in the small depression surrounding areas.Within Dongying depression,carbonate contents at the north steep slope belt,central rise belt,and so...