渝东北地区WX2井页岩气赋存特征及其勘探指示意义
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摘要
为了深入研究渝东北地区龙马溪组页岩气赋存特征,该文以WX2井页岩高温高压等温吸附及覆压孔隙度实验数据为基础,通过误差最小原则挑选了适合研究区的吸附模型,并基于孔隙度随有效应力变化关系建立游离气模型,综合分析了吸附气、游离气及总含气随埋藏深度的变化特征。研究结果表明:WX2井页岩不同温度下过剩吸附量随着压力增大,均呈现先增大后减小的趋势,随着温度的升高,最大吸附量逐渐减小,而校正后的绝对吸附量随压力增加,先迅速增大后增速放缓,且用D-A模型拟合绝对吸附量数据平均误差最小,基本可以反应研究区页岩真实吸附过程。页岩样品在加压过程中孔隙及微裂隙会逐渐闭合,卸压时绝大部分会重新打开,存在部分塑性变形造成的不可逆损伤,但不可逆损伤所占比重较轻。不同方向样品孔隙度与有效应力之间具有负指数关系,富含层理页岩平行样品较垂直样品具有更大的初始孔隙度以及更强的孔隙应力敏感性。页岩气赋存特征综合受控于储集层特征、吸附能力、温度及压力等因素,其中温度对吸附气和游离气含量为负效应,储层压力为正效应;吸附气、游离气及总含气量均遵循先增大后减小的总体趋势,其中吸附气及游离气含量分别主要受控于温度及储层压力。此外,临界深度上下,页岩吸附态与游离态相对含量发生变化,其对页岩气富集评价具有重要意义。
To study the shale gas occurrence characteristics of the Longmaxi Formation in northeast Chongqing, the isothermaladsorption data under high temperature and high pressure and porosity data under burden pressure of the well WX2 shale wereanalyzed. According to the principle of minimum error, we have chosen a suitable adsorption model for the study area. Based on therelationship between porosity and effective stress, the free gas model is established. In addition, comprehensive analysis of thecharacteristics of adsorption gas, free gas, and changes in total gas with the buried depth was conducted. The results show that excessadsorption quantity of well WX2 shale increased first and then decreased under different temperatures with an increasing pressure. Themaximum adsorption capacity decreased gradually as the temperature increased. After correction, the absolute adsorption quantity shows a rapid increase first and then a slow increase with increasing pressures. As the absolute adsorption data can be fitted with D-A model with the minimum average error, it can represent the real adsorption process of shale in the study area. Pores and micro-cracks of shale samples will gradually close during pressurization, and reopen during depressurization. This process will cause irreversible damage by plastic deformation, but irreversible damage accounts for small proportion. Porosities of samples from different directions have a negative exponent relationship with effective stress. Parallel samples of lamina-rich shales have greater initial porosity and stronger pore stress sensitivity than the vertical samples. Shale gas occurrence characteristic is comprehensively controlled by reservoir characteristics, adsorption capacity, reservoir temperature, and reservoir pressure. Among them, temperature has the negative effects on adsorption gas content and free gas content, and the reservoir pressure has the positive effect. The adsorption gas content, free gas content and total content increases first then decreases. Adsorption gas content and free gas content are mainly controlled by temperature and reservoir pressure, respectively. In addition, relative abundance of adsorption gas and free gas will change near the critical depth, and this will be of great importance for evaluating shale gas enrichment.
To study the shale gas occurrence characteristics of the Longmaxi Formation in northeast Chongqing, the isothermaladsorption data under high temperature and high pressure and porosity data under burden pressure of the well WX2 shale wereanalyzed. According to the principle of minimum error, we have chosen a suitable adsorption model for the study area. Based on therelationship between porosity and effective stress, the free gas model is established. In addition, comprehensive analysis of thecharacteristics of adsorption gas, free gas, and changes in total gas with the buried depth was conducted. The results show that excessadsorption quantity of well WX2 shale increased first and then decreased under different temperatures with an increasing pressure. Themaximum adsorption capacity decreased gradually as the temperature increased. After correction, the absolute adsorption quantity shows a rapid increase first and then a slow increase with increasing pressures. As the absolute adsorption data can be fitted with D-A model with the minimum average error, it can represent the real adsorption process of shale in the study area. Pores and micro-cracks of shale samples will gradually close during pressurization, and reopen during depressurization. This process will cause irreversible damage by plastic deformation, but irreversible damage accounts for small proportion. Porosities of samples from different directions have a negative exponent relationship with effective stress. Parallel samples of lamina-rich shales have greater initial porosity and stronger pore stress sensitivity than the vertical samples. Shale gas occurrence characteristic is comprehensively controlled by reservoir characteristics, adsorption capacity, reservoir temperature, and reservoir pressure. Among them, temperature has the negative effects on adsorption gas content and free gas content, and the reservoir pressure has the positive effect. The adsorption gas content, free gas content and total content increases first then decreases. Adsorption gas content and free gas content are mainly controlled by temperature and reservoir pressure, respectively. In addition, relative abundance of adsorption gas and free gas will change near the critical depth, and this will be of great importance for evaluating shale gas enrichment.
引文
曹环宇,朱传庆,邱楠生.2016.川东地区古生界主要泥页岩最高古温度特征[J].地球物理学报,59(3):1017-1029.
邓宾,刘树根,王国芝,等.2013.四川盆地南部地区新生代隆升剥露研究--低温热年代学证据[J].地球物理学报,56(6):1958-1973.
董大忠,邹才能,杨桦,等.2012.中国页岩气勘探开发进展与发展前景[J].石油学报,(增刊1):107-114.
郭彤楼,张汉荣.2014.四川盆地焦石坝页岩气田形成与富集高产模式[J].石油勘探与开发,41(1):28-36.
郭彤楼.2016.涪陵页岩气田发现的启示与思考[J].地学前缘,23(1)29-43.
郭旭升,胡东风,李宇平,等.2016.海相和湖相页岩气富集机理分析与思考:以四川盆地龙马溪组和自流井组大安寨段为例[J].地学前缘,23(2):18-28.
郭旭升.2014.南方海相页岩气“二元富集”规律--四川盆地及周缘龙马溪组页岩气勘探实践认识[J].地质学报,88(7):1209-1218.
何治亮,聂海宽,张钰莹.2016.四川盆地及其周缘奥陶系五峰组-志留系龙马溪组页岩气富集主控因素分析[J].地学前缘,23(2):8-17.
纪文明,宋岩,姜振学,等.2016.四川盆地东南部龙马溪组页岩微-纳米孔隙结构特征及控制因素[J].石油学报,37(2):182-195.
金之钧,胡宗全,高波,等.2016.川东南地区五峰组-龙马溪组页岩气富集与高产控制因素[J].地学前缘,23(1):1-10.
李传亮,孔祥言,徐献芝,等.2003.多孔介质的流变模型研究[J].力学学报,35(2):230-234.
李艳芳,邵德勇,吕海刚,等.2015.四川盆地五峰组-龙马溪组海相页岩元素地球化学特征与有机质富集的关系[J].石油学报,36(12)1470-1483.
梁峰,拜文华,邹才能,等.2016.渝东北地区巫溪2井页岩气富集模式及勘探意义[J].石油勘探与开发,43(3):1-9.
刘洪林,王红岩,方朝合,等.2016.中国南方海相页岩气超压机制及选区指标研究[J].地学前缘,23(2):48-54.
刘军,姚艳斌,朱正杰,等.2015.渝东南地区黑色岩系储集层特征及含气性评价[J].矿物岩石地球化学通报,34(5):1021-1026.
刘若冰.2015.超压对川东南地区五峰组-龙马溪组页岩储层影响分析[J].沉积学报,33(4):817-827.
刘树根,邓宾,钟勇,等.2016.四川盆地及周缘下古生界页岩气深埋藏-强改造独特地质作用[J].地学前缘,23(1):11-28.
聂海宽,包书景,高波,等.2012.四川盆地及其周缘上奥陶统-下志留统页岩气成藏体系研究[J].石油实验地质,34(2):115-119.
汤庆艳,张铭杰,余明,等.2013.页岩气形成机制的生烃热模拟研究[J]煤炭学报,38(5):742-747.
唐相路,姜振学,张莺莺,等.2015.渝东南地区页岩气富集区差异性分布成因[J].西安石油大学学报(自然科学版),30(3):24-30.
魏志红.2015.四川盆地及其周缘五峰组-龙马溪组页岩气的晚期逸散[J].石油与天然气地质,36(4):659-665.
夏威,于炳松,孙梦迪.2015.渝东南YK1井下寒武统牛蹄塘组底部黑色页岩沉积环境及有机质富集机制[J].矿物岩石,35(2):70-80.
夏阳,金衍,陈勉,等.2015.页岩气渗流数学模型[J].科学通报,60(24)2259-2271.
肖贤明,王茂林,魏强,等.2015.中国南方下古生界页岩气远景区评价[J].天然气地球科学,26(8):1433-1445.
熊小辉,王剑,余谦,等.2015.富有机质黑色页岩形成环境及背景的元素地球化学反演--以渝东北地区田坝剖面五峰组-龙马溪组页岩为例[J].天然气工业,35(4):25-32.
郇璇,张小兵,韦欢文.2015.基于不同类型煤吸附甲烷的吸附势重要参数探讨[J].煤炭学报,40(8):1859-1864.
游声刚,郭茜,耿小烬,等.2015.页岩含气量的影响因素分析及含气量测试方法[J].中国矿业,24(12):80-85.
张金川,金之钧,袁明生.2004.页岩气成藏机理和分布[J].天然气工业24(7):15-18.
张雪芬,陆现彩,张林晔,等.2010.页岩气的赋存形式研究及其石油地质意义[J].地球科学进展,25(6):597-604.
朱炎铭,陈尚斌,方俊华,等.2010.四川地区志留系页岩气成藏的地质背景[J].煤炭学报,35(7):1160-1164.
邹才能,董大忠,王社教,等.2010.中国页岩气形成机理、地质特征及资源潜力[J].石油勘探与开发,37(6):641-653.
邹才能,董大忠,王玉满,等.2015.中国页岩气特征、挑战及前景(一)[J].石油勘探与开发,42(6):689-701.
邹才能,董大忠,王玉满,等.2016.中国页岩气特征、挑战及前景(二)[J].石油勘探与开发,43(2):166-178.
耶格J C和库克N G W.1981.岩石力学基础[M].北京:科学出版社:268-272.
Athy L F.1930.Density,porosity,and compaction of sedimentary rocks[J]AAPG Bulletin,14(1):1-24.
Curtis J B.2002.Fractured shale-gas systems[J].AAPG bulletin,86(11)1921-1938.
Giles M R,Indrelid S L and James D M D.1998.Compaction the grea unknown in basin modeling[J].London:Geological Society,Specia Publications,141(1):15-43.
Harpalani S,Prusty B K and Dutta P.2006.Methane/CO2sorption modelin for coalbed methane production and CO2sequestration[J].Energy and Fuels,20(4):1591-1599.
JI W M,Song Y,Jiang Z X,et al.2015.Estimation of marine shale methan adsorption capacity based on experimental investigations of Lowe Silurian Longmaxi formation in the Upper Yangtze Platform,south China[J].Marine and Petroleum Geology,68:94-106.
Milliken K L,Rudnicki M,Awwiller D N,et al.2013.Organic matterehosted pore system,Marcellus Formation(Devonian),Pennsylvania[J].AAPGBull,97:177-200.
Singh H and Javadpour F.2016.Langmuir slip-Langmuir sorption permeability model of shale[J].Fuel,164:28-37.
Wang Y,Zhu Y M,Liu S M,et al.2016.Methane adsorption measurement and modeling for organic-rich marine shale samples[J].Fuel,172301-309.
邓宾,刘树根,王国芝,等.2013.四川盆地南部地区新生代隆升剥露研究--低温热年代学证据[J].地球物理学报,56(6):1958-1973.
董大忠,邹才能,杨桦,等.2012.中国页岩气勘探开发进展与发展前景[J].石油学报,(增刊1):107-114.
郭彤楼,张汉荣.2014.四川盆地焦石坝页岩气田形成与富集高产模式[J].石油勘探与开发,41(1):28-36.
郭彤楼.2016.涪陵页岩气田发现的启示与思考[J].地学前缘,23(1)29-43.
郭旭升,胡东风,李宇平,等.2016.海相和湖相页岩气富集机理分析与思考:以四川盆地龙马溪组和自流井组大安寨段为例[J].地学前缘,23(2):18-28.
郭旭升.2014.南方海相页岩气“二元富集”规律--四川盆地及周缘龙马溪组页岩气勘探实践认识[J].地质学报,88(7):1209-1218.
何治亮,聂海宽,张钰莹.2016.四川盆地及其周缘奥陶系五峰组-志留系龙马溪组页岩气富集主控因素分析[J].地学前缘,23(2):8-17.
纪文明,宋岩,姜振学,等.2016.四川盆地东南部龙马溪组页岩微-纳米孔隙结构特征及控制因素[J].石油学报,37(2):182-195.
金之钧,胡宗全,高波,等.2016.川东南地区五峰组-龙马溪组页岩气富集与高产控制因素[J].地学前缘,23(1):1-10.
李传亮,孔祥言,徐献芝,等.2003.多孔介质的流变模型研究[J].力学学报,35(2):230-234.
李艳芳,邵德勇,吕海刚,等.2015.四川盆地五峰组-龙马溪组海相页岩元素地球化学特征与有机质富集的关系[J].石油学报,36(12)1470-1483.
梁峰,拜文华,邹才能,等.2016.渝东北地区巫溪2井页岩气富集模式及勘探意义[J].石油勘探与开发,43(3):1-9.
刘洪林,王红岩,方朝合,等.2016.中国南方海相页岩气超压机制及选区指标研究[J].地学前缘,23(2):48-54.
刘军,姚艳斌,朱正杰,等.2015.渝东南地区黑色岩系储集层特征及含气性评价[J].矿物岩石地球化学通报,34(5):1021-1026.
刘若冰.2015.超压对川东南地区五峰组-龙马溪组页岩储层影响分析[J].沉积学报,33(4):817-827.
刘树根,邓宾,钟勇,等.2016.四川盆地及周缘下古生界页岩气深埋藏-强改造独特地质作用[J].地学前缘,23(1):11-28.
聂海宽,包书景,高波,等.2012.四川盆地及其周缘上奥陶统-下志留统页岩气成藏体系研究[J].石油实验地质,34(2):115-119.
汤庆艳,张铭杰,余明,等.2013.页岩气形成机制的生烃热模拟研究[J]煤炭学报,38(5):742-747.
唐相路,姜振学,张莺莺,等.2015.渝东南地区页岩气富集区差异性分布成因[J].西安石油大学学报(自然科学版),30(3):24-30.
魏志红.2015.四川盆地及其周缘五峰组-龙马溪组页岩气的晚期逸散[J].石油与天然气地质,36(4):659-665.
夏威,于炳松,孙梦迪.2015.渝东南YK1井下寒武统牛蹄塘组底部黑色页岩沉积环境及有机质富集机制[J].矿物岩石,35(2):70-80.
夏阳,金衍,陈勉,等.2015.页岩气渗流数学模型[J].科学通报,60(24)2259-2271.
肖贤明,王茂林,魏强,等.2015.中国南方下古生界页岩气远景区评价[J].天然气地球科学,26(8):1433-1445.
熊小辉,王剑,余谦,等.2015.富有机质黑色页岩形成环境及背景的元素地球化学反演--以渝东北地区田坝剖面五峰组-龙马溪组页岩为例[J].天然气工业,35(4):25-32.
郇璇,张小兵,韦欢文.2015.基于不同类型煤吸附甲烷的吸附势重要参数探讨[J].煤炭学报,40(8):1859-1864.
游声刚,郭茜,耿小烬,等.2015.页岩含气量的影响因素分析及含气量测试方法[J].中国矿业,24(12):80-85.
张金川,金之钧,袁明生.2004.页岩气成藏机理和分布[J].天然气工业24(7):15-18.
张雪芬,陆现彩,张林晔,等.2010.页岩气的赋存形式研究及其石油地质意义[J].地球科学进展,25(6):597-604.
朱炎铭,陈尚斌,方俊华,等.2010.四川地区志留系页岩气成藏的地质背景[J].煤炭学报,35(7):1160-1164.
邹才能,董大忠,王社教,等.2010.中国页岩气形成机理、地质特征及资源潜力[J].石油勘探与开发,37(6):641-653.
邹才能,董大忠,王玉满,等.2015.中国页岩气特征、挑战及前景(一)[J].石油勘探与开发,42(6):689-701.
邹才能,董大忠,王玉满,等.2016.中国页岩气特征、挑战及前景(二)[J].石油勘探与开发,43(2):166-178.
耶格J C和库克N G W.1981.岩石力学基础[M].北京:科学出版社:268-272.
Athy L F.1930.Density,porosity,and compaction of sedimentary rocks[J]AAPG Bulletin,14(1):1-24.
Curtis J B.2002.Fractured shale-gas systems[J].AAPG bulletin,86(11)1921-1938.
Giles M R,Indrelid S L and James D M D.1998.Compaction the grea unknown in basin modeling[J].London:Geological Society,Specia Publications,141(1):15-43.
Harpalani S,Prusty B K and Dutta P.2006.Methane/CO2sorption modelin for coalbed methane production and CO2sequestration[J].Energy and Fuels,20(4):1591-1599.
JI W M,Song Y,Jiang Z X,et al.2015.Estimation of marine shale methan adsorption capacity based on experimental investigations of Lowe Silurian Longmaxi formation in the Upper Yangtze Platform,south China[J].Marine and Petroleum Geology,68:94-106.
Milliken K L,Rudnicki M,Awwiller D N,et al.2013.Organic matterehosted pore system,Marcellus Formation(Devonian),Pennsylvania[J].AAPGBull,97:177-200.
Singh H and Javadpour F.2016.Langmuir slip-Langmuir sorption permeability model of shale[J].Fuel,164:28-37.
Wang Y,Zhu Y M,Liu S M,et al.2016.Methane adsorption measurement and modeling for organic-rich marine shale samples[J].Fuel,172301-309.