储层物性影响因素及注水开发后的变化——以辽东湾坳陷Z油田为例
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摘要
为摸清研究区储层长期注水开发后物性定量变化规律,以辽东湾坳陷Z油田东二下段三角洲前缘储层密闭取心为研究对象,综合利用岩矿分析、扫描电镜、X衍射、扫描伽马、常规物性、测井水淹解释等资料,从储层物性影响因素入手,系统研究了不同成因类型、不同渗透率储层水驱前后渗透率的变化规律,量化了不同水淹程度储层渗透率的变化幅度。研究结果表明:研究区储层物性的主要影响因素是黏土矿物和孔喉结构,二者与储层原始物性的大小息息相关,且在注水开发后两因素均发生了明显变化并导致渗透率的改变;黏土矿物含量与储层原始渗透率呈负相关的幂函数关系,黏土矿物含量越大,储层原始渗透率越低;孔喉大小与储层原始渗透率呈正相关关系,孔喉半径平均值、孔喉半径中值越大,储层原始渗透率越高;随着注水冲刷程度的加强,黏土矿物含量逐渐降低,而孔喉半径分布趋向于均匀化,且有增大趋势。黏土矿物和孔喉结构两者的变化导致储层渗透率随着水淹程度的加强整体上呈现增大的趋势,渗透率分布主值区向右移动,高值渗透率比例增加,低值渗透率比例减小。此外,笔者归纳总结了砂体成因类型相同、岩心扫描伽马值相近、渗透率级别相同的储层岩样在低、中、强水淹程度相对于未水淹岩心的渗透率变化量,详细分析了渗透率不同变化的原因及其对剩余油分布的影响。该研究为油田中后期剩余油精细描述提供了新思路,对油田高含水期深入挖潜、高效开发具有指导作用。
In order to find out the quantitative changes in reservoir physical properties after long-term waterflooding development of the Z oil field in the Liaodong Bay Depression,taking the sealed core of E3 dL2,a delta front reservoir as the research target,and comprehensively using microscope,scanning electron microscope,X diffraction,scanning gamma ray as tools,we systematically studied the permeability changes of the reservoirs of different genesis with different permeability before and after water flooding,and quantitatively correlated the variation in reservoir permeability with water output.The results show that,in the study area,clay minerals and pore throat structure are the main factors affecting the reservoir physical properties,including both the original reservoir permeability and the permeability after water injection.The total amount of clay minerals is rather different in the distributary channel sands and the mouth bar sands.And the composition of clay minerals,or the kaolinite and illite/smectite ratio depends upon the genesis of sand body.The total volume of clay minerals and the original permeability of reservoirs are negatively related.The larger the total volume of clay minerals,the lower the original permeability of reservoir.However,the pore throat size is positively correlated with the original permeability of the reservoir.The larger the mean pore throat radius,the higher the original permeability of the reservoir.With the increase in water flooding,the integral number of clay minerals decreases gradually,and the distribution of pore throat radius tends to be homogenized.As the result,the reservoir permeability will show a tendency of increase with the increase in water-out.Statistical analysis shows that the genetic type of reservoir sand bodies are critical important to the permeability and their changes in the water flooding process as well as the residual oil distribution.This study provides a new idea for the detailed description of remaining oil in the middle to late development stage of an oil field,and is effective to improve development efficiently in the high water cut stage.
In order to find out the quantitative changes in reservoir physical properties after long-term waterflooding development of the Z oil field in the Liaodong Bay Depression,taking the sealed core of E3 dL2,a delta front reservoir as the research target,and comprehensively using microscope,scanning electron microscope,X diffraction,scanning gamma ray as tools,we systematically studied the permeability changes of the reservoirs of different genesis with different permeability before and after water flooding,and quantitatively correlated the variation in reservoir permeability with water output.The results show that,in the study area,clay minerals and pore throat structure are the main factors affecting the reservoir physical properties,including both the original reservoir permeability and the permeability after water injection.The total amount of clay minerals is rather different in the distributary channel sands and the mouth bar sands.And the composition of clay minerals,or the kaolinite and illite/smectite ratio depends upon the genesis of sand body.The total volume of clay minerals and the original permeability of reservoirs are negatively related.The larger the total volume of clay minerals,the lower the original permeability of reservoir.However,the pore throat size is positively correlated with the original permeability of the reservoir.The larger the mean pore throat radius,the higher the original permeability of the reservoir.With the increase in water flooding,the integral number of clay minerals decreases gradually,and the distribution of pore throat radius tends to be homogenized.As the result,the reservoir permeability will show a tendency of increase with the increase in water-out.Statistical analysis shows that the genetic type of reservoir sand bodies are critical important to the permeability and their changes in the water flooding process as well as the residual oil distribution.This study provides a new idea for the detailed description of remaining oil in the middle to late development stage of an oil field,and is effective to improve development efficiently in the high water cut stage.
引文
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[10]杜庆龙.长期注水开发砂岩油田储层渗透率变化规律及微观机理[J].石油学报,2016,37(9):1159-1164.
[11]张雪芳,刘宗宾,刘超,等.辽东湾坳陷X油田黏土矿物对注水开发储层物性的影响[J].大庆石油地质与开发,2017,36(5):62-67.
[12]张雪芳,刘宗宾,刘超,等.辽东湾坳陷S油田三角洲前缘储层构型及其对剩余油分布的控制[J].东北石油大学学报,2016,40(6):1-8.
[13]张雪芬,陆现彩,刘庆,等.东营凹陷沙河街组砂岩中自生高岭石特征及其成因探讨[J].南京大学学报:自然科学,2013,49(3):331-338.
[14]邵淑骁,曾溅辉,张善文,等.东营凹陷沙河街组砂岩储层高岭石类型、特征及其成因[J].沉积学报,2015,33(6):1204-1210.
[15]陈鑫,钟建华,袁静,等.渤南洼陷古近系高岭石发育特征及转化机理[J].石油勘探与开发,2009,36(4):456-461.
[16]王芙蓉,何生,杨智,等.蒙皂石黏土矿物不正常转化的研究[J].油气地质与采收率,2006,13(4):25-27.
[17]姜在兴.沉积学[M].北京:石油工业出版社,2010.
[18]朱筱敏.沉积岩石学[M].北京:石油工业出版社,2008.
[2]张雪芳,刘宗宾,刘超,等.辽东湾坳陷S油田三角洲前缘储层构型及其对剩余油分布的控制[J].东北石油大学学报,2016,40(6):1-8.
[3]田文静.长庆盘古梁油田储层物性变化特征研究[D].西安:西安石油大学,2017,07.
[4]朱丽红,杜庆龙,姜雪岩,等.陆相多层砂岩油藏特高含水期三大矛盾特征及对策[J].石油学报,2015,36(2):210-216.
[5]张洪兴,刘青年.大庆砂岩油层水淹后岩石物性参数变化实验研究[C]∥大庆石油管理局勘探开发研究院.大庆油田勘探开发研究论文集.北京:石油工业出版社,1995:325-337.
[6]李中超,陈洪德,余成林,等.严重非均质油藏注水开发流体动力地质作用[J].石油勘探与开发,2013,40(2):209-214.
[7]李浩,王香文,刘双莲.老油田储层物性参数变化规律研究[J].西南石油大学学报:自然科学版,2009,31(2):85-89.
[8]朱丽红,杜庆龙,李忠江,等.高含水期储集层物性和润湿性变化规律研究[J].石油勘探与开发,2004,31(增刊):82-84.
[9]杨满平,高超,闫栋栋,等.特低渗透油藏单井产量递减规律及其影响因素——以长庆油田盘古梁长6油藏为例[J].油气地质与采收率,2011,18(4):68-71.
[10]杜庆龙.长期注水开发砂岩油田储层渗透率变化规律及微观机理[J].石油学报,2016,37(9):1159-1164.
[11]张雪芳,刘宗宾,刘超,等.辽东湾坳陷X油田黏土矿物对注水开发储层物性的影响[J].大庆石油地质与开发,2017,36(5):62-67.
[12]张雪芳,刘宗宾,刘超,等.辽东湾坳陷S油田三角洲前缘储层构型及其对剩余油分布的控制[J].东北石油大学学报,2016,40(6):1-8.
[13]张雪芬,陆现彩,刘庆,等.东营凹陷沙河街组砂岩中自生高岭石特征及其成因探讨[J].南京大学学报:自然科学,2013,49(3):331-338.
[14]邵淑骁,曾溅辉,张善文,等.东营凹陷沙河街组砂岩储层高岭石类型、特征及其成因[J].沉积学报,2015,33(6):1204-1210.
[15]陈鑫,钟建华,袁静,等.渤南洼陷古近系高岭石发育特征及转化机理[J].石油勘探与开发,2009,36(4):456-461.
[16]王芙蓉,何生,杨智,等.蒙皂石黏土矿物不正常转化的研究[J].油气地质与采收率,2006,13(4):25-27.
[17]姜在兴.沉积学[M].北京:石油工业出版社,2010.
[18]朱筱敏.沉积岩石学[M].北京:石油工业出版社,2008.