黄骅坳陷千米桥潜山奥陶系峰峰组—马家沟组白云岩成因

白云岩是黄骅坳陷千米桥潜山奥陶系主要储集层,具有层位分布较稳定,分布面积广和物性好、储产能力强的特点.本文通过该地区白云岩地层岩心、岩屑微观特征、岩相古地理环境、碳氧同位素分析以及包裹体分析,认为主要有3种成因的白云岩:①潮坪环境中,由准同生期蒸发作用引起交代成因的白云岩;②发生于海水潜流与淡水潜流混合带,由混合水交代作用形成的白云岩;③发生在深埋藏期,由热液沿裂缝进入地层并对岩石进行交代而形成的白云岩.

Geneses of the dolomite of Fengfeng Formation-Majiagou Formation of Ordovician system in Qian miqiao buried hill, Huanghua Depression

Dolomite, the main reservoir in Qianmiqiao buried hill in Huanghua Depression, distributes stably and widely, which has fine reservoir properties and good reserving and producing ability. According to the analyses of the cores, the micro-characteristics of the detritus, the lithofacies, the palaeogeographic environment, the carbon-oxygen isotope, and the inclusions, it is held that there are mainly three genetic types of the dolomite: one is the metasomatism caused by the evaporation in tidal-flat in penecontemporaneous period; one is the metasomatism caused by the mixture of sea water with fresh water in the mixing zone of sea-water underwater current with fresh water underwater current; another is the metasomatism caused by hot water entering the layer along the formation fractures during the deep burial period.