钻井液对高煤阶煤层气解吸率损害评价方法研究

高煤阶煤层气储层渗透率极低,孔隙空间小,在钻井液侵入后极易改变煤层孔隙结构或孔隙分布,直接影响煤层气的产出。因此,高煤阶煤层气储层受钻井液影响后的解吸率损害评价成为煤层气储层损害评价的一个重要指标。结合煤层气储层特点和钻开储层后钻井液侵入方式,建立了钻井液对煤层气解吸率损害的评价方法,以便深入研究煤层气储层损害规律,形成煤层气储层保护技术。

The assessment approach for the desorption rate of high-rank coalbed methane damaged by drilling fluid

The high-rank coalbed methane reservoir has very low permeability and small pore space .After the drilling fluid invading ,the pore configuration or pore distribution of the reservoir will be changed so as to directly influence coalbed methane production .Therefore ,the damage evaluation of desorption rate after the drilling fluid invading the reservoir is an important indicator of the degree of the reservoir damage .Combined with characteristics of the coalbed methane reservoir and the infiltrated modes of the drilling fluid ,an assessment approach for the desorption rate of the coalbed methane dam -aged by the drilling fluid was established to further study on damaging rule of the coalbed methane reservoir .As a result , a reservoir protection technology for the high -rank coalbed methane reservoir was formed .