煤层气压裂井裂缝参数优化及效果评价
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摘要
因煤层复杂渗流机理及低孔低渗特征,煤层气均需采取压裂改造措施进行开采。为了正确认识压裂参数对煤层气井产能、采出程度及井网部署的影响规律,从储层应力形变及煤层气解吸、扩散、渗流流固耦合分析出发,建立压裂井气水两相非线性渗流模型,研究裂缝参数、储层非均质性对井距及井网类型优化的影响,并且采用注入压降试井解释对压裂工艺参数进行评价。研究结果表明:煤层流体以非线性渗流为主,物性呈现先下降后上升的特征,存在启动压力梯度的影响;井距优化应考虑裂缝方向、裂缝穿透比、裂缝导流能力等因素的影响;矩形与菱形井网选择要参考储层各向异性系数的临界值;避免注入压降测试中井筒液面的变化及测试段的选择对试井解释结果的影响,提高压裂效果解释评价准确性。研究对煤层气压裂井裂缝、井网参数优化及提高压裂效果评价准确性具有较好的指导意义。
Due to complex seepage mechanism and weak reservoir property,CBM reservoir requires exploitation by hydraulic fracturing.In order to study fracturing parameters' influencing laws on productivity,recovery efficiency and well network,this paper establishes one non-linear gas-water seepage model for fractured wells.Stress deformation,fluid-solid interaction,CBM desorption,and diffusion researches are carried out.Injection pressure-drop well test method is taken to evaluate fracturing effects.The result proves that reservoir porosity declines initially and rises later,permeability is non-linearly affected by threshold pressure gradient;well space optimization depends on fracture orientation,fracture penetration ratio,and fracture conductivities;rectangle and rhombus well pattern selection refers to critical ratio of reservoir anisotropy values.Due to dynamic changes of wellbore liquid level injection pressure-drop well test interpretation should be improved further.This study is of great significance to improve fracturing evaluation and parameters' optimization.
Due to complex seepage mechanism and weak reservoir property,CBM reservoir requires exploitation by hydraulic fracturing.In order to study fracturing parameters' influencing laws on productivity,recovery efficiency and well network,this paper establishes one non-linear gas-water seepage model for fractured wells.Stress deformation,fluid-solid interaction,CBM desorption,and diffusion researches are carried out.Injection pressure-drop well test method is taken to evaluate fracturing effects.The result proves that reservoir porosity declines initially and rises later,permeability is non-linearly affected by threshold pressure gradient;well space optimization depends on fracture orientation,fracture penetration ratio,and fracture conductivities;rectangle and rhombus well pattern selection refers to critical ratio of reservoir anisotropy values.Due to dynamic changes of wellbore liquid level injection pressure-drop well test interpretation should be improved further.This study is of great significance to improve fracturing evaluation and parameters' optimization.
引文
[1] Ju Yiwen,Li Qingguang,Yan Zhifeng,et al.Origin types of CBM and their geochemical research progress[J].Journal of China Coal Society,2014,39(5):807-814.琚宜文,李清光,颜志丰,等.煤层气成因类型及其地球化学研究进展[J].煤炭学报,2014,39(5):807-814.
[2] Meng Yanjun,Tang Dazhen,Xu Hao,et al.Division of coalbed methane desorption stages and its significance[J].Petroleum Exploration and Development,2014,41(5):612-618.孟艳军,汤达祯,许浩,等.煤层气解吸阶段划分方法及其意义[J].石油勘探与开发,2014,41(5):612-618.
[3] Chen Xinping,Huo Quanming,Lin Jiandong,et al.The relation between CBM content and the elastic parameters of CBM reservoirs:Reasoning and initial probing[J].Chinese Journal of Geophysics,2013,56(8):2837-2848.陈信平,霍全明,林建东,等.煤层气储层含气量与其弹性参数之间的关系——思考与初探[J].地球物理学报,2013,56(8):2837-2848.
[4] Zhang Gaoqun,Liu Tongyi.Hydrofracturing fluid and proppant for coalbed gas reservoirs:Research and use[J].Oilfield Chemistry,1999,16(1):18-21.张高群,刘通义.煤层压裂液和支撑剂的研究及应用[J].油田化学,1999,16(1):18-21.
[5] Zhang Suian,Cao Lihu,Du Caixia.Study on CBM production mechanism and control theory of bottom-hole pressure and coal fines during CBM well production[J].Journal of China Coal Society,2014,39(9):1928-1931.张遂安,曹立虎,杜彩霞.煤层气井产气机理及排采控压控粉研究[J].煤炭学报,2014,39(9):1928-1931.
[6] Lu Yiyu,Yang Feng,Ge Zhaolong,et al.Comparative experiment on influence of clear fracturing fluid and water on coal seam permeability[J].Journal of China Coal Society,2015,40(1):93-97.卢义玉,杨枫,葛兆龙,等.清洁压裂液与水对煤层渗透率影响对比试验研究[J].煤炭学报,2015,40(1):93-97.
[7] Wang Jianjun.Analysis on fracturing and initiation pressure and initiation location in multi slicing seam[J].Coal Science and Technology,2015,43(5):81-87.王建军.多分层煤层压裂起裂压力及起裂位置研究[J].煤炭科学技术2015,43(5):81-87.
[8] Li Xianzhong,Lin Baiquan,Zhai Cheng,et al.The mechanism of breaking coal and rock by pulsating pressure wave in single low permeability seam[J].Journal of China Coal Society,2013,38(6):918-923.李贤忠,林柏泉,翟成,等.单一低透煤层脉动水力压裂脉动波破煤岩机理[J].煤炭学报,2013,38(6):918-923.
[9] Ren Fei,Zhang Suian,Li Xinzi,et al.Optimization design of fracture parameters in coalbed methane(CBM)morizontal well staged fracturing[J].Natural Gas and Oil,2014,32(1):58-62.任飞,张遂安,李辛子,等.煤层气水平井分段压裂裂缝参数优化设计[J].天然气与石油,2014,32(1):58-62.
[10] Yan Xia,Li Xiaojun,Zhao Hui,et al.Research on well interference of coalbed methane wells and its application[J].Lithologic Reservoirs,2015,27(2):126-132.闫霞,李小军,赵辉,等.煤层气井井间干扰研究及应用[J].岩性油气藏,2015,27(2):126-132.
[11] Wang Xin,Ding Yunhong,Li Zhilong.A study on influence of different fracture fluid to hydraulic fracturing in coal reservoir[J].Well Testing,2009,18(2):2-4.王欣,丁云宏,李志龙,等.不同压裂液类型对煤岩水力压裂的影响研究[J].油气井测试,2009,18(2):2-4.
[12] Ye Jianping,Shi Baosheng,Zhang Chuncai.Coal reservoir permeability and its controlling factors in China[J].Journal of China Coal Society,1999,24(2):118-122.叶建平,史保生,张春才.中国煤储层渗透性及其主要影响因素[J].煤炭学报,1999,24(2):118-122.
[13] Chen Zhenhong,Jia Chengzao,Song Yan,et al.Differences and origin of physical properties of low-rank and high-rank coalbed methanes[J].Acta Petrolei Sinica,2008,29(2):179-184.陈振宏,贾承造,宋岩,等.高、低煤阶煤层气藏物性差异及其成因[J].石油学报,2008,29(2):179-184.
[14] Li Chuanliang,Peng Chaoyang,Zhu Suyang.Coalbed methane is adsorption gas underground[J].Lithologic Reservoirs,2013,25(2):112-115.李传亮,彭朝阳,朱苏阳.煤层气其实是吸附气[J].岩性油气藏,2013,25(2):112-115.
[15] Li Chuanliang,Peng Chaoyang.Research on the flow mechanism of coalbed methane[J].Lithologic Reservoirs,2011,23(4):9-11.李传亮,彭朝阳.煤层气的开采机理研究[J].岩性油气藏,2011,23(4):9-11.
[16] Li Xiangfang,Shi Juntai,Du Xiyao,et al.Transport mechanism of desorbed gas in coalbed methane reservoirs[J].Petroleum Exploration and Development,2012,39(2):204-209.李相方,石军太,杜希瑶,等.煤层气藏开发降压解吸气运移机理[J].石油勘探与开发,2012,39(2):204-209.
[17] Li Xiangfang,Pu Yunchao,Sun Changyu,et al.Recognition of absorption/desorption theory in coalbed methane reservoir and shale gas reservoir[J].Acta Petrolei Sinica,2014,35(6):1113-1129.李相方,蒲云超,孙长宇,等.煤层气与页岩气吸附/解吸的理论再认识[J].石油学报,2014,35(6):1113-1129.
[18] Ni Guangyu,Cheng Wei,Ren Yifa.Desorption and absorption tests of coal seams in Yan No.1 Well and application study[J].China Coalbed Methane,2011,8(2):35-38.倪光禹,程伟,任以发.延1井煤层解吸与吸附实验及应用研究[J].中国煤层气,2011,8(2):35-38.
[19] Seidle J P.Experimental Measurement of Coal Matrix Shrinkage Due to Gas Desorption and Implications for Cleat Permeability Increases[C].SPE 30010,1995.
[20] Li Jinhai,Su Xianbo,Lin Xiaoying,et al.Relationship between discharge rate and productivity of coalbed methane wells[J].Journal of China Coal Society,2009,34(3):376-380.李金海,苏现波,林晓英,等.煤层气井排采速率与产能的关系[J].煤炭学报,2009,34(3):376-380.
[21] Dou Xinzhao,Jiang Bo,Qin Yong,et al.Pattern and mechanism of metamorphism of Late Permian coal in western Guizhou[J].Journal of China Coal Society,2012,37(3):424-429.窦新钊,姜波,秦勇,等.黔西地区晚二叠世煤层变质规律及机理研究[J].煤炭学报,2012,37(3):424-429.
[22] Yi Wei,Xiong Xianyong,Wang Wei,et al.Study on occurrence features of coalbed methane in Heyang area,Ordos Basin[J].Lithologic Reservoirs,2015,27(2):38-45.伊伟,熊先钺,王伟,等.鄂尔多斯盆地合阳地区煤层气赋存特征研究[J].岩性油气藏,2015,27(2):38-45.
[23]Wu Yaqin,Shao Guoliang,Xu Yaohui,et al.Geological unit division and development model optimization of coalbed methane:A case study from Zhengzhuang block in Qinshui Basin[J].Lithologic Reservoirs,2016,28(6):125-133.吴雅琴,邵国良,徐耀辉,等.煤层气开发地质单元划分及开发方式优化——以沁水盆地郑庄区块为例[J].岩性油气藏,2016,28(6):125-133.
[24] Zhang Tingshan,Zhang Zhicheng,Wu Kunyu.Restoration of formation compaction and inversion of deposition rate in Dianqianbei exploration area[J].Lithologic Reservoirs,2016,28(5):99-106.张廷山,张志诚,伍坤宇.滇黔北地区地层压实恢复及沉积速率反演[J].岩性油气藏,2016,28(5):99-106.
[25] Zhao Xianzheng,Yang Yanhui,Sun Fenjin,et al.Enrichment mechanism and exploration and development technologies of high rank coalbed methane in south Qinshui Basin,Shanxi Province[J].Petroleum Exploration and Development,2016,43(2):303-309.赵贤正,杨延辉,孙粉锦,等.沁水盆地南部高阶煤层气成藏规律与勘探开发技术[J].石油勘探与开发,2016,43(2):303-309.
[2] Meng Yanjun,Tang Dazhen,Xu Hao,et al.Division of coalbed methane desorption stages and its significance[J].Petroleum Exploration and Development,2014,41(5):612-618.孟艳军,汤达祯,许浩,等.煤层气解吸阶段划分方法及其意义[J].石油勘探与开发,2014,41(5):612-618.
[3] Chen Xinping,Huo Quanming,Lin Jiandong,et al.The relation between CBM content and the elastic parameters of CBM reservoirs:Reasoning and initial probing[J].Chinese Journal of Geophysics,2013,56(8):2837-2848.陈信平,霍全明,林建东,等.煤层气储层含气量与其弹性参数之间的关系——思考与初探[J].地球物理学报,2013,56(8):2837-2848.
[4] Zhang Gaoqun,Liu Tongyi.Hydrofracturing fluid and proppant for coalbed gas reservoirs:Research and use[J].Oilfield Chemistry,1999,16(1):18-21.张高群,刘通义.煤层压裂液和支撑剂的研究及应用[J].油田化学,1999,16(1):18-21.
[5] Zhang Suian,Cao Lihu,Du Caixia.Study on CBM production mechanism and control theory of bottom-hole pressure and coal fines during CBM well production[J].Journal of China Coal Society,2014,39(9):1928-1931.张遂安,曹立虎,杜彩霞.煤层气井产气机理及排采控压控粉研究[J].煤炭学报,2014,39(9):1928-1931.
[6] Lu Yiyu,Yang Feng,Ge Zhaolong,et al.Comparative experiment on influence of clear fracturing fluid and water on coal seam permeability[J].Journal of China Coal Society,2015,40(1):93-97.卢义玉,杨枫,葛兆龙,等.清洁压裂液与水对煤层渗透率影响对比试验研究[J].煤炭学报,2015,40(1):93-97.
[7] Wang Jianjun.Analysis on fracturing and initiation pressure and initiation location in multi slicing seam[J].Coal Science and Technology,2015,43(5):81-87.王建军.多分层煤层压裂起裂压力及起裂位置研究[J].煤炭科学技术2015,43(5):81-87.
[8] Li Xianzhong,Lin Baiquan,Zhai Cheng,et al.The mechanism of breaking coal and rock by pulsating pressure wave in single low permeability seam[J].Journal of China Coal Society,2013,38(6):918-923.李贤忠,林柏泉,翟成,等.单一低透煤层脉动水力压裂脉动波破煤岩机理[J].煤炭学报,2013,38(6):918-923.
[9] Ren Fei,Zhang Suian,Li Xinzi,et al.Optimization design of fracture parameters in coalbed methane(CBM)morizontal well staged fracturing[J].Natural Gas and Oil,2014,32(1):58-62.任飞,张遂安,李辛子,等.煤层气水平井分段压裂裂缝参数优化设计[J].天然气与石油,2014,32(1):58-62.
[10] Yan Xia,Li Xiaojun,Zhao Hui,et al.Research on well interference of coalbed methane wells and its application[J].Lithologic Reservoirs,2015,27(2):126-132.闫霞,李小军,赵辉,等.煤层气井井间干扰研究及应用[J].岩性油气藏,2015,27(2):126-132.
[11] Wang Xin,Ding Yunhong,Li Zhilong.A study on influence of different fracture fluid to hydraulic fracturing in coal reservoir[J].Well Testing,2009,18(2):2-4.王欣,丁云宏,李志龙,等.不同压裂液类型对煤岩水力压裂的影响研究[J].油气井测试,2009,18(2):2-4.
[12] Ye Jianping,Shi Baosheng,Zhang Chuncai.Coal reservoir permeability and its controlling factors in China[J].Journal of China Coal Society,1999,24(2):118-122.叶建平,史保生,张春才.中国煤储层渗透性及其主要影响因素[J].煤炭学报,1999,24(2):118-122.
[13] Chen Zhenhong,Jia Chengzao,Song Yan,et al.Differences and origin of physical properties of low-rank and high-rank coalbed methanes[J].Acta Petrolei Sinica,2008,29(2):179-184.陈振宏,贾承造,宋岩,等.高、低煤阶煤层气藏物性差异及其成因[J].石油学报,2008,29(2):179-184.
[14] Li Chuanliang,Peng Chaoyang,Zhu Suyang.Coalbed methane is adsorption gas underground[J].Lithologic Reservoirs,2013,25(2):112-115.李传亮,彭朝阳,朱苏阳.煤层气其实是吸附气[J].岩性油气藏,2013,25(2):112-115.
[15] Li Chuanliang,Peng Chaoyang.Research on the flow mechanism of coalbed methane[J].Lithologic Reservoirs,2011,23(4):9-11.李传亮,彭朝阳.煤层气的开采机理研究[J].岩性油气藏,2011,23(4):9-11.
[16] Li Xiangfang,Shi Juntai,Du Xiyao,et al.Transport mechanism of desorbed gas in coalbed methane reservoirs[J].Petroleum Exploration and Development,2012,39(2):204-209.李相方,石军太,杜希瑶,等.煤层气藏开发降压解吸气运移机理[J].石油勘探与开发,2012,39(2):204-209.
[17] Li Xiangfang,Pu Yunchao,Sun Changyu,et al.Recognition of absorption/desorption theory in coalbed methane reservoir and shale gas reservoir[J].Acta Petrolei Sinica,2014,35(6):1113-1129.李相方,蒲云超,孙长宇,等.煤层气与页岩气吸附/解吸的理论再认识[J].石油学报,2014,35(6):1113-1129.
[18] Ni Guangyu,Cheng Wei,Ren Yifa.Desorption and absorption tests of coal seams in Yan No.1 Well and application study[J].China Coalbed Methane,2011,8(2):35-38.倪光禹,程伟,任以发.延1井煤层解吸与吸附实验及应用研究[J].中国煤层气,2011,8(2):35-38.
[19] Seidle J P.Experimental Measurement of Coal Matrix Shrinkage Due to Gas Desorption and Implications for Cleat Permeability Increases[C].SPE 30010,1995.
[20] Li Jinhai,Su Xianbo,Lin Xiaoying,et al.Relationship between discharge rate and productivity of coalbed methane wells[J].Journal of China Coal Society,2009,34(3):376-380.李金海,苏现波,林晓英,等.煤层气井排采速率与产能的关系[J].煤炭学报,2009,34(3):376-380.
[21] Dou Xinzhao,Jiang Bo,Qin Yong,et al.Pattern and mechanism of metamorphism of Late Permian coal in western Guizhou[J].Journal of China Coal Society,2012,37(3):424-429.窦新钊,姜波,秦勇,等.黔西地区晚二叠世煤层变质规律及机理研究[J].煤炭学报,2012,37(3):424-429.
[22] Yi Wei,Xiong Xianyong,Wang Wei,et al.Study on occurrence features of coalbed methane in Heyang area,Ordos Basin[J].Lithologic Reservoirs,2015,27(2):38-45.伊伟,熊先钺,王伟,等.鄂尔多斯盆地合阳地区煤层气赋存特征研究[J].岩性油气藏,2015,27(2):38-45.
[23]Wu Yaqin,Shao Guoliang,Xu Yaohui,et al.Geological unit division and development model optimization of coalbed methane:A case study from Zhengzhuang block in Qinshui Basin[J].Lithologic Reservoirs,2016,28(6):125-133.吴雅琴,邵国良,徐耀辉,等.煤层气开发地质单元划分及开发方式优化——以沁水盆地郑庄区块为例[J].岩性油气藏,2016,28(6):125-133.
[24] Zhang Tingshan,Zhang Zhicheng,Wu Kunyu.Restoration of formation compaction and inversion of deposition rate in Dianqianbei exploration area[J].Lithologic Reservoirs,2016,28(5):99-106.张廷山,张志诚,伍坤宇.滇黔北地区地层压实恢复及沉积速率反演[J].岩性油气藏,2016,28(5):99-106.
[25] Zhao Xianzheng,Yang Yanhui,Sun Fenjin,et al.Enrichment mechanism and exploration and development technologies of high rank coalbed methane in south Qinshui Basin,Shanxi Province[J].Petroleum Exploration and Development,2016,43(2):303-309.赵贤正,杨延辉,孙粉锦,等.沁水盆地南部高阶煤层气成藏规律与勘探开发技术[J].石油勘探与开发,2016,43(2):303-309.