改善煤岩储层渗流能力的氧化液处理实验研究  

An experimental study on oxidizer treatment used to improve the seepage capacity of coal reservoirs

作　　者：康毅力[1] 涂莹谦 游利军[1] 李相臣[1] 皇凡生 Kang Yili;Tu Yingqian;You Lijun;Li Xiangchen;Huang Fansheng(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]"油气藏地质及开发工程"国家重点实验室.西南石油大学

出　　处：《天然气工业》2018年第9期61-69,共9页Natural Gas Industry

基　　金：国家自然科学基金面上项目"富有机质页岩氧化致裂增渗加速气体传输机理研究"(编号:51674209)

摘　　要：煤岩储层物理增产难,利用强氧化剂的氧化作用改造煤岩储层可以提高煤层气采收率,但目前基于煤层气领域的氧化研究却相对较少,系统评价氧化作用对煤岩储层渗流能力影响的实验研究则更为鲜见。为此,选取新疆托克逊黑山矿区侏罗系西山窑组煤样,分别开展了柱状煤样和粉状煤样与过氧化氢作用实验,测试了柱状煤样渗透率、粉状煤样溶蚀率和浸泡液性能参数等,并借助X射线衍射、扫描电镜、红外光谱及润湿角测量等手段,分析煤岩与过氧化氢的反应机制和改善煤岩渗流能力的机理,进而对比氧化作用与酸化作用的改造效果。研究结果表明:(1)煤岩氧化后渗透率明显提高,为初始渗透率的1.4~3.2倍;(2)氧化后煤岩产生大量微裂隙和溶蚀孔,可显著改善孔隙连通性,煤岩表面缔合态羟基和羧基增多,表面水湿性变弱;(3)有机质、黄铁矿等组分易被氧化消耗,同时产生的H+、小分子脂肪酸等又进一步溶蚀无机矿物组分;(4)氧化作用兼具酸化作用溶解无机矿物的优势,产生煤粉程度较弱、可控。结论认为,强氧化剂作用于煤岩储层具有成为一种新的煤岩储层增产改造技术的潜力。It is difficult to realize physical stimulation of coal reservoirs,and the recovery factor of coalbed methane(CBM)can be enhanced by applying strong oxidizer and oxidation action to stimulate coal reservoirs.At present,however,the oxidation in the field of CBM is less researched,and the experimental study to systematically evaluate the effect of oxidation action on the seepage capacity of coal reservoirs is rare.In this paper,the coal samples taken from coal seams of the Jurassic Xishanyao Fm in the Heishan Coal Mine,Tuokexun,Xinjiang,were selected as the study objects.Hydrogen peroxide solution immersion experiments were carried out on columnar and powdered coal samples,respectively to measure the permeability of columnar coal samples,the dissolution rate of powdered coal samples and the property parameters of hydrogen peroxide solution.Then,the reaction mechanisms between coal and hydrogen peroxide and the mechanisms to improve the seepage capacity of coal reservoir were analyzed by means of X-ray diffraction,scanning electron microscope(SEM),infrared spectrum and wetting angle measurement.Finally,the stimulation effect of oxidation was compared with that of acidification.And the following research results were obtained.First,the permeability of coal samples is increased significantly after oxidation,and it is 1.4–3.2 times that the original permeability.Second,a large number of micro-fractures and dissolved pores are formed in coals after the oxidation,and consequently pore connectivity is improved greatly.Thus,the amount of associative hydroxyl and carboxyl functional groups on the surface of coals increases,and the water wettability on the surface reduces.Third,organic matter and pyrite are oxidized and consumed easily,and the generated H+and small-molecule aliphatic acids will dissolve inorganic mineral components further.And fourth,oxidation also has the advantage of acidification dissolving inorganic mineral components,so the coal powder is weak and controllable.In conclusion,strong oxidizer has the pot

关 键 词：煤岩 氧化作用 渗透率 孔隙连通性 酸化作用 微裂隙和溶蚀孔 溶解无机矿物 煤岩储层增产改造 

分 类 号：TE312[石油与天然气工程—油气田开发工程]