CO 2 Trapping in Reservoirs with Fluvial Architecture: Sensitivity to Heterogeneity in Permeability and Constitutive Relationship Parameters for Different Rock Types
CO 2 Trapping in Reservoirs with Fluvial Architecture: Sensitivity to Heterogeneity in Permeability and Constitutive Relationship Parameters for Different Rock Types
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DOI：
10.1016/j.petrol.2016.09.008
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发表时间：
2017-07
影响因子：
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通讯作者：
N. Gershenzon;R. Ritzi;D. Dominic;E. Mehnert;Roland Okwen;Christopher Patterson
中科院分区：
文献类型：
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作者：
N. Gershenzon;R. Ritzi;D. Dominic;E. Mehnert;Roland Okwen;Christopher Patterson
一些重要的CO2储层候选者表现出反映河流沉积的沉积结构，这通常包括不同岩石类型之间的小尺度（分米到米）结构相。因此，这种类型的储层的固有渗透率和本构关系参数（毛管压力和相对渗透率特征曲线）的高度对比的空间分布是常见的。在此之前，我们表明，小规模的异质性组织在河流沉积结构控制的动态CO2羽在注入和postinjectionperiod。这是由于（1）有效渗透率的高度各向异性导致CO2横向运移，（2）毛细管钉扎作用导致的捕获，这是对折断毛细管捕获的补充。任何特定储层的详细岩石物理和地质参数通常是不确定的，这激发了参数敏感性研究。本文的目的是分析毛细管捕获和溶解的敏感性，在高度非均质河流型储层的基本岩石物理参数和岩石成分的变化。结果表明：（1）岩石类型之间渗透率的差异越大，CO2羽流越大，毛细管捕获和溶解速率越大;高低渗透岩石比例的变化（高渗透性簇的连接性的差异）不影响折断捕获和溶解，尽管它强烈地影响它们的空间分布。尽管溶解和折断毛细管捕获可能由于参数可变性而变化高达40%，通过毛细钉扎的捕获可以变化一个数量级。
A number of important CO2reservoir candidates exhibit sedimentary architecture reflecting fluvial deposition, which typically includes small-scale (decimeter to meter) textural facies among different rock types. As a result, highly contrasting spatial distribution of intrinsic permeability and constitutive relationship parameters (capillary pressure and relative permeability characteristic curves) are common for this type of reservoir. Previously, we showed that small-scale heterogeneity organized in fluvial depositional architecture controls the dynamics of a CO2plume during the injection and postinjection periods. This is due to (1) highly anisotropic effective permeability causing CO2to move in laterally, and (2) trapping by capillary pinning, which is in addition to snap-off capillary trapping.The detailed petrophysical and geological parameters of any specific reservoir are typically uncertain, which motivates studies of parameter sensitivity. The goal of this paper is to analyze the sensitivity of capillary trapping and dissolution to the variability in basic petrophysical parameters and rock composition in highly heterogeneous fluvial-type reservoirs. We show that (1) the larger the contrast in permeability between rock types the larger the CO2plume and the larger the rate of capillary trapping and dissolution; (2) an increase in capillary pressure contrast increases pinning trapping; and (3) the variability in the proportion between high- and low-permeability rocks (difference in connectivity of high-permeability clusters) does not affect snap-off trapping and dissolution, although it does strongly affect their spatial distributions.Though dissolution and snap-off capillary trapping may vary by up to 40% because of parameter variability, the trapping by capillary pinning may vary by an order of magnitude.