Cementation is a primary factor reducing the porosity of carbonate rocks. It is a challenge to accurately model cementation for reservoir quality prediction because cementation is often a syndepositional process. In addition, cementation requires fluid flow to transport chemical species for precipitation within the pore spaces in a sediment. The development of fully‐coupled depositional‐hydrogeochemical models for cementation prediction is desirable, but the parameters which control the extent of cementation need to be identified and evaluated. This study uses petrographic data from 583 carbonate samples from 15 wells in an Upper Jurassic (Kimmeridgian) reservoir at a giant oilfield in eastern Saudi Arabia to investigate the controlling effects of micrite content on cementation in carbonate rocks. The results indicate that the amount of cement decreases with increasing micrite content in the carbonate rocks analysed. In addition, a modified Houseknecht method has been developed to assess the relative fractions of porosity reduction in carbonate sediments due to compaction and cementation. The method highlights variations in depositional porosity for different rock textures and distinguishes microporosity from interparticle porosity. In the studied samples, the total porosity loss due to compaction and cementation is generally less than 45%, and samples lose more porosity due to compaction than cementation. The relative importance of compaction and cementation in reducing porosity is different for different rock textures: wackestones and mudstones lose porosity mostly as a result of compaction, while grainstones, mud‐lean packstones and packstones lose porosity due to both compaction and cementation.

中文翻译：

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东沙特阿拉伯上侏罗统碳酸盐岩储层中微晶石含量对钙质胶结的影响

胶结作用是降低碳酸盐岩孔隙度的主要因素。为固井质量预测准确地建立胶结模型是一个挑战，因为胶结通常是一个同沉积过程。另外，胶结作用要求流体流动以输送化学物质，以便在沉积物的孔隙内沉淀。建立固结预测的全耦合沉积-水地球化学模型是可取的，但是控制固结程度的参数需要确定和评估。这项研究使用沙特阿拉伯东部一个大型油田上侏罗统（基默尼迪安河）储层中15口井的583个碳酸盐样品的岩相学数据，研究了微尘含量对碳酸盐岩胶结作用的控制作用。结果表明，随着碳酸盐岩中微晶含量的增加，水泥用量减少。另外，已经开发了一种改良的Houseknecht方法来评估由于压实和胶结作用而使碳酸盐沉积物中孔隙度降低的相对分数。该方法突出显示了不同岩石质地的沉积孔隙度变化，并将微孔隙度与颗粒间孔隙度区分开。在研究的样品中，由于压实和胶结造成的总孔隙率损失通常小于45％，并且由于压实而导致的样品孔隙率损失比胶结更多。对于不同的岩石质地，压实和胶结作用在降低孔隙度方面的相对重要性有所不同：瓦克石和泥岩主要由于压实作用而失去孔隙度，而花岗石，