Abstract Light hydrocarbons produced from unconventional tight shale reservoirs with matrix permeability in nano-Darcy range accounts for more than half of the petroleum production in the United States in the past several years. This has been enabled mainly by the drilling of long horizontal wells coupled with extensive hydraulic fracturing. A typical fracturing job for a horizontal well requires two to five million gallons of water which imposes significant challenges in many areas of the world that lack water resources. In addition, treatment and disposal of produced fracturing fluids can be expensive and may negatively impact the environment. Here we show a ‘water-free’ stimulation method to produce light hydrocarbons from the extremely tight reservoirs using electromagnetic (EM) waves to heat the formation and elevate pore-water pressure. We demonstrated in the laboratory that microwave heating pulverized shales and other tight rocks without confinement and generated extensive fractures within shales with 15 MPa isotropic confinement pressures. Our calculation indicates that for typical shale reservoirs pore-water pressure can increase to 90 MPa or higher that is sufficient to stimulate the formation for production with a less than 100 °C temperature increase of the reservoir. Using a simplified coupled model of EM heating and thermal diffusion, we estimated that with practically reasonable amount of power input the EM heating can stimulate a sufficiently large volume of tight reservoirs to produce light hydrocarbons.

中文翻译：

---

用于石油生产的页岩油藏的电磁热刺激

摘要 过去几年美国石油产量中，纳米达西范围内基质渗透率的非常规致密页岩油藏生产的轻烃占石油产量的一半以上。这主要是通过钻长水平井和广泛的水力压裂实现的。水平井的典型压裂作业需要 2 到 500 万加仑的水，这给世界上许多缺乏水资源的地区带来了重大挑战。此外，生产的压裂液的处理和处置可能很昂贵并且可能对环境产生负面影响。在这里，我们展示了一种“无水”增产方法，使用电磁 (EM) 波加热地层并提高孔隙水压力，从极其致密的储层中生产轻质碳氢化合物。我们在实验室中证明，微波加热粉碎了页岩和其他致密岩石而不受限制，并在 15 MPa 各向同性限制压力下在页岩内产生了广泛的裂缝。我们的计算表明，对于典型的页岩储层，孔隙水压力可以增加到 90 MPa 或更高，足以在储层温度升高小于 100 °C 的情况下刺激地层生产。使用电磁加热和热扩散的简化耦合模型，我们估计在实际合理的功率输入下，电磁加热可以刺激足够大量的致密储层以生产轻烃。