普光气田碳酸盐岩储层暂堵转向酸压技术
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摘要
普光气田主体气藏属超深层、高含硫、中孔、低渗透构造-岩性气藏,主要含气层为三叠系飞仙关组、二叠系长兴组,产出剖面显示部分层段未动用或动用率低。暂堵转向酸压技术可改善产气剖面,提高储层动用程度,普光气田拟采用该技术。目前微地震监测技术虽对暂堵压裂裂缝转向及其扩展规律进行了定量分析,但受信号干扰误差较大。本文应用真三轴模拟实验装置,采用与储层物性类似的露头岩心,加载与实际储层对应的三向应力,采用自主研发的可降解酸压暂堵剂和高温清洁转向酸体系进行酸压暂堵转向实验。由露头暂堵酸压实验可知,转向酸作为压裂液明显有利于复杂裂缝的形成,加入暂堵剂后,起裂压力增加了5～10 MPa,且明显有新裂缝出现,表明暂堵剂暂堵效果显著。由暂堵酸压现场试验可知:在暂堵剂进入储层阶段,暂堵剂最高暂堵压力为66.13 MPa,比未注入暂堵剂的最高施工压力高了近20 MPa,表明暂堵剂在不断压实并封堵高渗层;在转向酸进入储层阶段,施工压力波动明显,表明转向酸向低渗层转移并不断开启新裂缝,与前期露头岩心暂堵酸压实验结果类似,验证了暂堵转向酸压技术的可靠性。
The principal gas reservoir of Puguang Gasfield is an ultra deep structural-lithological gas reservoir of high sulfur content, moderate porosity and low permeability, and its main gas bearing layers are the Triassic Feixianguan Formation and the Permian Changxing Formation. Production profiles show that some intervals are not produced or less produced. Temporary plugging,diverting and acid fracturing technology can improve the gas production profile and increase the reservoir producing degree. And Puguang Gasfield tends to adopt this technology. At present, microseismic monitoring technology can be used to analyze quantitatively the diverting and propagation laws of fractures created by temporary plugging fracturing, but its error is larger due to the signal interference. Experiments on temporary plugging, diverting and acid fracturing were conducted by using the independently developed degradable temporary plugging agent for acid fracturing and high-temperature clean diverting acid system. In the experiments, the true triaxial simulation experiment device was used to apply the triaxial stress corresponding to the actual reservoir,and the outcrop cores whose physical property is similar to that of the reservoir were adopted. The temporary plugging and acid fracturing experiment on the outcrops shows that the diverting acid, acting as the fracturing fluid, is obviously favorable for the formation of complex fractures. And after the temporary plugging agent is added, the fracture initiation pressure is increased by 5-10 MPa and new fractures emerge obviously, indicting remarkable effect of temporary plugging. The on-site temporary plugging and acid fracturing experiment reveals that when the temporary plugging agent moves into the reservoir, its maximum temporary plugging pressure is 66.13 MPa, which is nearly 20 MPa higher than the maximum construction pressure without temporary plugging agent,indicating that the temporary plugging agent is compacting and sealing the high-permeability layers continuously. And when the diverting acid moves into the reservoir, the construction pressure fluctuates greatly, indicating that the diverting acid is transferring to the low-permeability layers and initiating new fractures continuously. The on-site experimental results are similar to the experimental results of outcrop cores, verifying the reliability of the temporary plugging, diverting and acid fracturing technology.
The principal gas reservoir of Puguang Gasfield is an ultra deep structural-lithological gas reservoir of high sulfur content, moderate porosity and low permeability, and its main gas bearing layers are the Triassic Feixianguan Formation and the Permian Changxing Formation. Production profiles show that some intervals are not produced or less produced. Temporary plugging,diverting and acid fracturing technology can improve the gas production profile and increase the reservoir producing degree. And Puguang Gasfield tends to adopt this technology. At present, microseismic monitoring technology can be used to analyze quantitatively the diverting and propagation laws of fractures created by temporary plugging fracturing, but its error is larger due to the signal interference. Experiments on temporary plugging, diverting and acid fracturing were conducted by using the independently developed degradable temporary plugging agent for acid fracturing and high-temperature clean diverting acid system. In the experiments, the true triaxial simulation experiment device was used to apply the triaxial stress corresponding to the actual reservoir,and the outcrop cores whose physical property is similar to that of the reservoir were adopted. The temporary plugging and acid fracturing experiment on the outcrops shows that the diverting acid, acting as the fracturing fluid, is obviously favorable for the formation of complex fractures. And after the temporary plugging agent is added, the fracture initiation pressure is increased by 5-10 MPa and new fractures emerge obviously, indicting remarkable effect of temporary plugging. The on-site temporary plugging and acid fracturing experiment reveals that when the temporary plugging agent moves into the reservoir, its maximum temporary plugging pressure is 66.13 MPa, which is nearly 20 MPa higher than the maximum construction pressure without temporary plugging agent,indicating that the temporary plugging agent is compacting and sealing the high-permeability layers continuously. And when the diverting acid moves into the reservoir, the construction pressure fluctuates greatly, indicating that the diverting acid is transferring to the low-permeability layers and initiating new fractures continuously. The on-site experimental results are similar to the experimental results of outcrop cores, verifying the reliability of the temporary plugging, diverting and acid fracturing technology.
引文
[1]廖凯飞,谭国华,曾正清,等.普光地区陆相须家河组低渗致密砂岩气藏气层识别[J].石油天然气学报(江汉石油学院学报),2013,35(10):10-13.LIAO Kaifei,TAN Guohua,ZENG Zhengqing,et al.Identification of low permeability and tight sandstone gas reservoirs in Xujiahe Formation of Puguang Area[J].Journal of Oil and Gas Technology,2013,35(10):10-13.
[2]唐群英,尹太举,路遥,等.川东北普光地区须家河组裂缝特征描述[J].岩性油气藏,2012,24(2):42-47.TANG Qunying,YIN Taiju,LU Yao,et al.Fracture features description of Xujiahe formation in Puguang area,northeastern Sichuan Basin[J].Lithologic Reservoirs,2012,24(2):42-47.
[3]钱治家,钟克修.川东北地区须家河组沉积相与储层特征[J].天然气工业,2009,29(6):9-12.QIAN Zhijia,ZHONG Kexiu.Sedimentary facies and reservoir features of the Xujiahe formation in northeastern Sichuan Basin[J].Natural Gas Industry,2009,29(6):9-12.
[4]唐立章,张贵生,张晓鹏,等.川西须家河组致密砂岩成藏主控因素[J].天然气工业,2004,24(9):5-7.TANG Lizhang,ZHANG Guisheng,ZHANG Xiaopeng,et al.Main control factors of forming the tight sandstone gas reservoirs in Xujiahe Formation in West Sichuan Depression[J].Natural Gas Industry,2004,24(9):5-7.
[5]孙利,刘家铎,王峻,等.普光陆相地层天然气成藏条件与主控因素分析[J].西南石油大学学报(自然科学版),2012,34(6):9-16.SUN Li,LIU Jiaduo,WANG Jun,et al.Analysis on dominating factors and conditions for the formation of natural gas reservoir of puguang terrestrial formation[J].Journal of Southwest Petroleum University(Science&Technology Edition),2012,34(6):9-16.
[6]张胜利.暂堵转向压裂技术在川东北致密砂岩储层中的应用[J].石化技术,2016,23(3):59,146.ZHANG Shengli.Application of temporary plugging and diverting fracturing technology in tight sandstone reservoir in northeast Sichuan[J].Petrochemical Industry Technology,2016,23(3):59,146.
[7]刘天宇,吴月先,曾科,等.转向压裂技术最优分类及应用范例剖析[J].钻采工艺,2010,33(5):58-61.LIU Tianyu,WU Yuexian,ZENG Ke,et al.Classification and application of steering fracturing technology[J].Drilling&Production Technology,2010,33(5):58-61.
[8]吴勇,陈凤,承宁.利用人工暂堵转向提高重复压裂效果[J].钻采工艺,2008,31(4):59-61.WU Yong,CHEN Feng,CHENG Ning.Enhancing refracturing effect with artificial temporary plugging technology[J].Drilling&Production Technology,2008,31(4):59-61.
[9]刘洪,赵金洲,胡永全,等.重复压裂气井造新缝机理研究[J].天然气工业,2004,24(12):102-104.LIU Hong,ZHAO Jinzhou,HU Yongquan,et al.Study on mechanism of inducing new fractures for refracturing gas wells[J].Natural Gas Industry,2004,24(12):102-104.
[10]何青琴,杨永全,何世明,等.低渗透油气田重复压裂诱导应力场模拟研究[J].天然气技术,2010,4(1):30-32.HE Qingqin,YANG Yongquan,HE Shiming,et al.Refracturing-induced stress field simulation of low-permeability oil and gas fields[J].Natural Gas Technology,2010,4(1):30-32.
[11]达引朋,赵文,卜向前,等.低渗透油田重复压裂裂缝形态规律研究[J].断块油气田,2012,19(6):781-784.DA Yinpeng,ZHAO Wen,BO Xiangqian,et al.Study on fracture pattern law for re-fracturing in low permeability reservoir[J].Faulk-Block Oil&Gas Field,2012,19(6):781-784.
[12]苏良银,庞鹏,达引朋,等.低渗透油田暂堵重复压裂堵剂用量优化与现场试验[J].断块油气田,2014,21(1):114-117.SU Liangyin,PANG Peng,DA Yinpeng,et al.Usage optimization and field test of blocking agent for tempor-al-blocked re-fracturing in low permeability oilfield[J].Fault-Block Oil&Gas Field,2014,21(1):114-117.
[13]陈勉,庞飞,金衍.大尺寸真三轴水力压裂模拟与分析[J].岩石力学与工程学报,2000,19(增1):868-872.CHEN Mian,PANG Fei,JIN Yan.Experiments and analysis on hydraulic fracturing by a large-size triaxial simulator[J].Chinese Journal of Rock Mechanics and Engineering,2000,19(S1):868-872.
[14]赵益忠,曲连忠,王幸尊,等.不同岩性地层水力压裂裂缝扩展规律的模拟实验[J].中国石油大学学报(自然科学版),2007,31(3):63-66.ZHAO Yizhong,QU Lianzhong,WANG Xingzun,et al.Simulation experiment on prolongation law of hydraulic fracture for different lithologic formations[J].Journal of China University of Petroleum(Natural Science Edition),2007,31(3):63-66.
[15]刘建升,杨永刚,张红岗,等.微地震监测技术在暂堵压裂工艺中的应用[J].石油化工应用,2016,35(8):68-73.LIU Jiansheng,YANG Yonggang,ZHANG Honggang,et al.Application of micro-seismic fracturing monitoring technology in temporary plugging and reoriented fracturing[J].Petrochemical Industry Application,2016,35(8):68-73.
[2]唐群英,尹太举,路遥,等.川东北普光地区须家河组裂缝特征描述[J].岩性油气藏,2012,24(2):42-47.TANG Qunying,YIN Taiju,LU Yao,et al.Fracture features description of Xujiahe formation in Puguang area,northeastern Sichuan Basin[J].Lithologic Reservoirs,2012,24(2):42-47.
[3]钱治家,钟克修.川东北地区须家河组沉积相与储层特征[J].天然气工业,2009,29(6):9-12.QIAN Zhijia,ZHONG Kexiu.Sedimentary facies and reservoir features of the Xujiahe formation in northeastern Sichuan Basin[J].Natural Gas Industry,2009,29(6):9-12.
[4]唐立章,张贵生,张晓鹏,等.川西须家河组致密砂岩成藏主控因素[J].天然气工业,2004,24(9):5-7.TANG Lizhang,ZHANG Guisheng,ZHANG Xiaopeng,et al.Main control factors of forming the tight sandstone gas reservoirs in Xujiahe Formation in West Sichuan Depression[J].Natural Gas Industry,2004,24(9):5-7.
[5]孙利,刘家铎,王峻,等.普光陆相地层天然气成藏条件与主控因素分析[J].西南石油大学学报(自然科学版),2012,34(6):9-16.SUN Li,LIU Jiaduo,WANG Jun,et al.Analysis on dominating factors and conditions for the formation of natural gas reservoir of puguang terrestrial formation[J].Journal of Southwest Petroleum University(Science&Technology Edition),2012,34(6):9-16.
[6]张胜利.暂堵转向压裂技术在川东北致密砂岩储层中的应用[J].石化技术,2016,23(3):59,146.ZHANG Shengli.Application of temporary plugging and diverting fracturing technology in tight sandstone reservoir in northeast Sichuan[J].Petrochemical Industry Technology,2016,23(3):59,146.
[7]刘天宇,吴月先,曾科,等.转向压裂技术最优分类及应用范例剖析[J].钻采工艺,2010,33(5):58-61.LIU Tianyu,WU Yuexian,ZENG Ke,et al.Classification and application of steering fracturing technology[J].Drilling&Production Technology,2010,33(5):58-61.
[8]吴勇,陈凤,承宁.利用人工暂堵转向提高重复压裂效果[J].钻采工艺,2008,31(4):59-61.WU Yong,CHEN Feng,CHENG Ning.Enhancing refracturing effect with artificial temporary plugging technology[J].Drilling&Production Technology,2008,31(4):59-61.
[9]刘洪,赵金洲,胡永全,等.重复压裂气井造新缝机理研究[J].天然气工业,2004,24(12):102-104.LIU Hong,ZHAO Jinzhou,HU Yongquan,et al.Study on mechanism of inducing new fractures for refracturing gas wells[J].Natural Gas Industry,2004,24(12):102-104.
[10]何青琴,杨永全,何世明,等.低渗透油气田重复压裂诱导应力场模拟研究[J].天然气技术,2010,4(1):30-32.HE Qingqin,YANG Yongquan,HE Shiming,et al.Refracturing-induced stress field simulation of low-permeability oil and gas fields[J].Natural Gas Technology,2010,4(1):30-32.
[11]达引朋,赵文,卜向前,等.低渗透油田重复压裂裂缝形态规律研究[J].断块油气田,2012,19(6):781-784.DA Yinpeng,ZHAO Wen,BO Xiangqian,et al.Study on fracture pattern law for re-fracturing in low permeability reservoir[J].Faulk-Block Oil&Gas Field,2012,19(6):781-784.
[12]苏良银,庞鹏,达引朋,等.低渗透油田暂堵重复压裂堵剂用量优化与现场试验[J].断块油气田,2014,21(1):114-117.SU Liangyin,PANG Peng,DA Yinpeng,et al.Usage optimization and field test of blocking agent for tempor-al-blocked re-fracturing in low permeability oilfield[J].Fault-Block Oil&Gas Field,2014,21(1):114-117.
[13]陈勉,庞飞,金衍.大尺寸真三轴水力压裂模拟与分析[J].岩石力学与工程学报,2000,19(增1):868-872.CHEN Mian,PANG Fei,JIN Yan.Experiments and analysis on hydraulic fracturing by a large-size triaxial simulator[J].Chinese Journal of Rock Mechanics and Engineering,2000,19(S1):868-872.
[14]赵益忠,曲连忠,王幸尊,等.不同岩性地层水力压裂裂缝扩展规律的模拟实验[J].中国石油大学学报(自然科学版),2007,31(3):63-66.ZHAO Yizhong,QU Lianzhong,WANG Xingzun,et al.Simulation experiment on prolongation law of hydraulic fracture for different lithologic formations[J].Journal of China University of Petroleum(Natural Science Edition),2007,31(3):63-66.
[15]刘建升,杨永刚,张红岗,等.微地震监测技术在暂堵压裂工艺中的应用[J].石油化工应用,2016,35(8):68-73.LIU Jiansheng,YANG Yonggang,ZHANG Honggang,et al.Application of micro-seismic fracturing monitoring technology in temporary plugging and reoriented fracturing[J].Petrochemical Industry Application,2016,35(8):68-73.