页岩油注气提高采收率现状及可行性分析

摘要/Abstract

摘要：

页岩油在世界范围内资源丰厚,具有广阔的开采前景。然而水平井以及大量水力压裂措施使得成本大大提高。大量的实验和数值模拟结果表明,通过注气能极大提高页岩油采收率,目前还没有将这一技术商业应用的成功案例,因此页岩油注气提高采收率是否可行还存在争论。通过对比页岩岩心气驱实验、页岩油注气数值模拟及矿场试验三个方面的研究,发现实验条件及数值模拟模型与实际页岩储层存在较大差异。结合李传亮提出的页岩储层微型岩性圈闭构造理论,得出只有在压裂改造,或建立正交水平井井网缩短井距的条件下进一步注气,才能达到提高页岩油采收率的目的。这对于我国乃至世界页岩油采收率的提高具有重要指导意义。

关键词: 页岩油, 注气, 提高采收率, 气驱实验, 数值模拟, 矿场试验, 可行性分析

Abstract:

Shale oil resources are rich around the world and have extraordinary exploitation prospects. However, drilling horizontal wells and huge amounts of hydraulic fracturing measures had sharply increased the cost. A large number of experiments and numerical simulations showed that the gas injection could significantly improve the shale oil recovery. Nevertheless, this technique had not been implemented to the practical exploitation of shale oil. Consequently, it was still controversial whether shale oil recovery could be optimized through gas injection or not. By the comparison of the gas displacement experiments of the shale cores, the numerical simulation of shale oil recovery by gas injection and the gas injection pilots in practical fields, it was found that the results from experimental conditions and numerical simulation models were different from those in field pilots. Li Chuanliang insisted that the shale reservoir was consisted of myriad micro-lithologic traps. It was concluded that only if the gas was injected after fracturing, or establishing an orthogonal horizontal well pattern to dense the well spacing, would the shale oil recovery be improved. It has essential guidance for the improvement of shale oil recovery in China or even in the world.

Key words: shale oil, gas injection, improved oil recovery, gas drive experiment, numerical simulation, field pilots, feasibility analysis

中图分类号:

TE341

梅海燕,何浪,张茂林,胡欣芮,毛恒博. 页岩油注气提高采收率现状及可行性分析[J]. 油气藏评价与开发, 2018, 8(6): 77-82.

Mei Haiyan,He Lang,Zhang Maolin,Hu Xinrui,Mao Hengbo. Status and feasibility analysis on improved shale-oil recovery by gas injection[J]. Reservoir Evaluation and Development, 2018, 8(6): 77-82.

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试验号	地区	年份	注入流体	注入方式
试验#1	北达科他州	2008	CO₂	吞吐
试验#2	蒙大纳州	2009	CO₂	吞吐
试验#3	北达科他州	2012	水	吞吐
试验#4	北达科他州	2012~2013	水	水驱
试验#5	北达科他州	2014	CO₂	直井注入
试验#6	蒙大纳州	2014	水	水驱
试验#7	北达科他州	2014	天然气	气驱

参数	值	参数	值
试验面积/km²	1.46	原始地层压力/MPa	16
储层有效厚度/m	7~8	原始地层体积系数	1.328
孔隙度,%	9~10	原油黏度/（mPa·s）	2~3
渗透率/10^-3μm²	0.01~0.1	原油重度/API	42
含水饱和度,%	55~59	地质储量/10⁸m³	12.72