煤层气水平井注氮增产改造技术

发布时间：2018-11-10 12:26

【摘要】：针对七元煤矿低孔、低压、低含水饱和度、高变质程度的煤储层特点和筛管完井煤层气解吸困难情况,为了实现瓦斯治理与煤层气共同开发的需要,探索出一套煤层气水平井筛管完井下的注氮增产改造技术。利用顶替排液、氮气驱替、憋井放喷3种氮气改造模式的不同特点,实施多次"注氮-憋压-放喷"作业,通过注氮改造可以清除近井污染,沟通煤层割理裂隙,改善井筒远处煤层渗透率,建立单相气体渗流通道,实现煤层气高效开发的目的。结果表明:七元煤矿5组水平井实施注氮增产改造技术后,单井日产气量提高3~20倍,实现了单井产量的突破。
[Abstract]:In view of the characteristics of coal reservoir with low porosity, low pressure, low water saturation, high metamorphism and difficulty in desorption of coal-bed gas in sieve completion wells, the need of gas treatment and codevelopment of coalbed gas can be realized in Qiyuan Coal Mine, which is characterized by low porosity, low pressure, low water saturation and high degree of metamorphism. A set of technology of nitrogen injection to increase production of coal bed methane horizontal well under sieve tube completion was explored. According to the different characteristics of three kinds of nitrogen transformation modes, such as displacement and drainage, nitrogen displacement and blowout, the operation of "nitrogen injection, pressure holding and releasing injection" can be carried out for many times. Through nitrogen injection transformation, the pollution of near well can be cleared and the cleats of coal seam can be communicated. The purpose of high efficiency development of coalbed methane is to improve the permeability of coal seam in the distance of wellbore and establish a single phase gas seepage channel. The results show that the daily gas production in Qiyuan coal mine can be increased by 3 ~ 20 times after the nitrogen injection technology is applied in 5 groups of horizontal wells, and the breakthrough of single well production has been realized.
【作者单位】：中联煤层气有限责任公司七元煤矿瓦斯治理与煤层气开发合作项目组;
【基金】：中海石油有限公司2015-2016年科技资助项目(YJQYWS-14-33)
【分类号】：TE377

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