西湖凹陷花港组低孔低渗砂岩储层中绿泥石环边的成因及其意义

发布时间：2018-11-21 15:57

【摘要】：西湖凹陷中北部渐新统花港组深层砂岩储层物性整体为低孔低渗,物性较好、测试产能高的优质储层以发育绿泥石环边为特征。根据铸体薄片、扫描电镜、X射线衍射、能谱等分析绿泥石环边成因及形成时间并探讨其意义。结果表明:环边里层是沉积时包裹碎屑颗粒的黏土微粒在成岩过程中铁离子的影响下绿泥石化而成;外层是由于铁离子的持续供给,围绕里层环边生长而成。绿泥石环边形成于溶蚀作用发生以前,并且早于石英加大边形成,既能缓解压实作用,又能抑制其他胶结物的形成,利于在深埋条件下保存原生孔隙;同时还能在保存原生孔隙的基础上促进后期溶蚀作用;另外,绿泥石环边利于形成较好的孔喉结构,并能提高成藏时油气充注程度。绿泥石环边是花港组深层形成优质储层的重要因素,对寻找优质储层和指导油气勘探具有重要意义。
[Abstract]:The physical properties of the deep sandstone reservoirs of the Huagang formation of the Oligocene in the central and northern part of Xihu sag are as a whole low porosity and low permeability and good physical properties. The high quality reservoirs with high test productivity are characterized by the development of chlorite ring edge. The origin and formation time of chlorite ring edge were analyzed according to the thin sheet, scanning electron microscope, X-ray diffraction and energy dispersive spectrum, and its significance was discussed. The results show that the inner layer of ring edge is formed by the influence of iron ion during diagenesis, and the outer layer is formed by the continuous supply of iron ions around the rim of the inner layer. Chlorite ring formed before dissolution, and formed earlier than quartz, which not only alleviated compaction, but also inhibited the formation of other cementation, which was favorable to preserve primary pores under the condition of deep burial. At the same time, it can promote the late dissolution on the basis of preserving the primary pores, in addition, the chlorite ring edge is conducive to the formation of a better pore throat structure, and can improve the degree of oil and gas filling during reservoir formation. Chlorite ring edge is an important factor for the formation of high quality reservoirs in Huagang formation, which is of great significance in finding high quality reservoirs and guiding oil and gas exploration.
【作者单位】：中海石油(中国)有限公司上海分公司;
【基金】：“十三五”国家科技重大专项(2016ZX05027-003)
【分类号】：P618.13

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