The Lower Fars Formation in the subsurface of north Kuwait consists of repeated fining upward sequences of sand, sandstone and shale. Two wells, one each from two north Kuwait fields, were selected to investigate the presence of calcrete and dolocrete in it. Total forty-four core samples of the host sediment, calcrete, and dolocrete were analyzed using thin section petrography, XRD, XRF, and SEM techniques. Additionally, granulometric analysis was also performed for the host sediments. Fabrics and textures of the studied calcrete indicate two genetic types, namely; phreatic groundwater and pedogenic that display several development stages with two end members: incipient and mature calcrete. It was concluded that the nature of the host sediments, the hydrogeochemical conditions, and the prevailing climate played significant role in the development of these calcrete horizons within Mutriba field. The occurrence of cyclic nodular dolocrete horizons within the South Ratqa sequence is mainly attributed to the difference in the chemistry of groundwater and nature of host sediments. Textures of the calcitized dolocretic horizons suggest that the migration of oil to the Lower Fars sequence took place after the completion of all diagenetic processes. Palustrine dolomicrite identified in the eastern part of the study area exclusively in two types as; nonfossiliferous and fossiliferous.

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北科威特中新世下法尔斯组内钙质和白云质层位的发生方式

科威特北部次表层的下法尔斯组包括反复细化向上的砂，砂岩和页岩层序。选择了两口井，每口井都来自科威特北部的两个油田，以研究其中有钙质和白质。使用薄层岩石学，XRD，XRF和SEM技术分析了宿主沉积物，钙质和白云母的总共44个岩心样品。另外，还对宿主沉积物进行了粒度分析。研究的钙质的结构和质地表明两种遗传类型，即：潜水地下水和成岩动物具有几个发展阶段，有两个最终成员：初期和成熟的混凝土。结论是，宿主沉积物的性质，水文地球化学条件，当时的气候在Mutriba田地这些钙质层的发育中起着重要作用。South Ratqa层序内环状节状白垩纪地层的出现主要归因于地下水化学和宿主沉积物性质的差异。钙化的白垩纪地层的纹理表明，所有成岩过程完成后，石油便迁移到了下法尔斯层序。在研究区域的东部仅识别出两种类型的古草白云岩：非化石和化石。钙化的白垩纪地层的纹理表明，所有成岩过程完成后，石油便迁移到了下法尔斯层序。在研究区域的东部仅识别出两种类型的古草白云岩：非化石和化石。钙化的白垩纪地层的纹理表明，所有成岩过程完成后，石油便迁移到了下法尔斯层序。在研究区域的东部仅识别出两种类型的古草白云岩：非化石和化石。