• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Transport in Porous Media >Stress-Dependent In Situ Gas Permeability in the Eagle Ford Shale
【24h】

Stress-Dependent In Situ Gas Permeability in the Eagle Ford Shale

机译：Eagle Ford页岩中应力相关的原位气体渗透率

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We measured argon gas permeability in three intact and one partially fractured Eagle Ford Shale samples documenting the stress dependence of horizontal (bedding parallel) in situ permeability of intact samples which varies between 1 and 10 nD (1 nD = 0.9869233 x 10(-21) m(2)), while the permeability of partially fractured sample varies between 18 and 37 nD. For all samples, permeability decreases by up to an order of magnitude while cycling the confining pressure (P-C) between 27.7 and 55.2 MPa at a constant pore pressure (P-P) of 14.4 MPa. Most of the permeability decrease is within the first loading and unloading cycle. During this first cycle, we also observe less than 2% decline in permeability over similar to 10 days when we held the P-C constant at 51.6-55.2 MPa, respectively. This suggests that the ongoing creep plays a relatively minor role. The subsequent P-C cycles result in a small decrease in permeability (similar to 6 to 26% variation between the start and the end of each cycle). We interpret that the initial permeability loss is due to the closing of micro-fractures-which we infer are caused by stress relief and gas expansion during sample retrieval and/or preparation. We interpret that the higher permeability of the partially fractured sample is mainly due to incomplete closure of a preexisting fracture, which extends nearly two-third the sample length. We document this dual-permeability structure from the observation of a dual-timescale pressure response behavior during the experiments at lower P-C-P-P. We find permeability decreases with increasing P-C-P-P; stress dependency of permeability follows an exponential relationship with a stress-sensitive gradient of 0.019-0.040 MPa-1. A better understanding of permeability variation with stress will help to reliably estimate in situ permeability and to better understand production evolution from unconventional shale reservoirs.
机译：我们测量了三个完整的和部分破裂的Eagle Ford页岩样品的氩气渗透率，记录了完整样品水平（平行于顺层）原位渗透率的应力依赖性，其变化范围为1到10 nD（1 nD = 0.9869233 x 10（-21） m（2）），而部分破裂的样品的渗透率在18到37 nD之间变化。对于所有样品，在恒定孔隙压力（P-P）为14.4 MPa时，围压（P-C）在27.7和55.2 MPa之间循环时，渗透率最多降低一个数量级。渗透率的大部分降低都在第一个加载和卸载周期内。在第一个循环中，当我们将P-C分别保持在51.6-55.2 MPa时，在大约10天的时间里，我们还观察到渗透率下降了不到2％。这表明正在进行的蠕变起着相对较小的作用。随后的P-C循环导致磁导率略有下降（类似于每个循环开始和结束之间的6％至26％的变化）。我们认为，初始渗透率损失是由于微裂缝的闭合所致，我们推断这是由于样品取回和/或制备过程中的应力释放和气体膨胀所致。我们解释说，部分破裂的样品的较高渗透率主要是由于先前存在的裂缝的闭合不完全所致，该裂缝延伸了样品长度的近三分之二。我们通过在较低的P-C-P-P实验期间观察到双重时标压力响应行为来记录这种双重渗透性结构。我们发现渗透率随P-C-P-P的增加而降低；渗透率的应力依赖性遵循指数关系，应力敏感梯度为0.019-0.040 MPa-1。更好地理解渗透率随应力的变化将有助于可靠地估算原位渗透率，并更好地理解非常规页岩储层的生产演化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号