Abstract Fracture stimulation using soundless cracking demolition agents (SCDAs) is a potential alternative technique to induce high-density fractures in sedimentary reservoir-rock as an auxiliary technique to improve the efficiency of enhanced oil and gas recovery efficiencies. However, to date, its application has been limited to fracture stimulation in dry rock masses. Therefore, using modified SCDAs, which can be used for underwater rock fracturing, a series of experiments was conducted to investigate the fracturing performance of SCDAs in saturated rock masses. 18 coarse-grained sandstone specimens were saturated in water, oil, and NaCl brine and fractured using three different SCDA types: a standard SCDA (S1), and two modified for underwater application (S2) and accelerated reaction rate (S3). Then, the fractured samples were scanned in the Australian Synchrotron, and the fractures were quantified using Avizo 9.0.1. The fracture initiation time and the total fracture network length and volume were found to be dependent on the saturated pore fluid of rock. Water saturation of samples increased the fracture initiation time by 16.5%, 24.1% and 13.68% for S1, S2, and S3 type SCDAs respectively and reduced the fracturing potential of SCDA by 59.5%, 32.49% and 66.67% compared to dry samples. This reduction was less apparent in oil-saturated samples as the high pore fluid viscosity of oil-saturated samples aid fracturing, which is explained by the Poiseuille equation. Increasing salinity in the saturation fluid from 0% to 12.5% was favourable for the fracturing efficiency of SCDAs because of the formation of CaCl2 in the pore fluid, which accelerates the reaction of SCDA. Fracture orientation also changed depending on the saturation fluid, which was again governed by the variation in reaction rate in SCDAs under different saturation conditions.

中文翻译：

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饱和条件对地质储层岩层中不同无声裂化爆破剂（SCDA）断裂性能的影响。

摘要 使用无声裂解爆破剂（SCDAs）进行裂缝增产是一种潜在的替代技术，可以在沉积储层岩石中诱导高密度裂缝，作为提高油气采收率的辅助技术。然而，迄今为止，它的应用仅限于干岩体中的裂缝刺激。因此，利用可用于水下岩石压裂的改性SCDAs，开展了一系列实验，研究了SCDAs在饱和岩体中的压裂性能。18 个粗粒砂岩试样在水、油和 NaCl 盐水中饱和，并使用三种不同的 SCDA 类型进行压裂：标准 SCDA (S1)，以及两种改进的水下应用 (S2) 和加速反应速率 (S3)。然后，在澳大利亚同步加速器中扫描断裂样品，并使用 Avizo 9.0.1 对断裂进行量化。发现裂缝起始时间和总裂缝网络长度和体积取决于岩石的饱和孔隙流体。样品含水饱和度使S1、S2和S3型SCDA的起裂时间分别增加16.5%、24.1%和13.68%，与干样品相比，SCDA的压裂潜力降低59.5%、32.49%和66.67%。这种降低在油饱和样品中不太明显，因为油饱和样品的高孔隙流体粘度有助于压裂，这可以通过泊肃叶方程来解释。将饱和流体的矿化度从 0% 增加到 12.5% 有利于 SCDAs 的压裂效率，因为在孔隙流体中形成 CaCl2，从而加速 SCDA 的反应。裂缝方向也根据饱和流体而变化，这再次受到不同饱和条件下 SCDA 反应速率变化的控制。