致密砂岩储层多尺度裂缝渗透率定量表征及开发意义
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摘要
为了研究不同尺度裂缝的渗流能力及其对天然气开发的影响,根据裂缝尺度,将库车坳陷克深5气藏的裂缝划分为4个级别,分别计算了每个级别裂缝的渗透率,并分析了裂缝线密度、有效开度对产能的影响,最后指出了开发井位部署的有利区域。研究表明:Ⅰ级裂缝的线密度为0. 10条/m,平均有效开度为1. 0~3. 0 cm,渗透率为8 300. 0×10~(-3)~225 000. 0×10~(-3)μm~2;Ⅱ级裂缝线密度为0. 21条/m,平均有效开度为1. 5 mm,渗透率为59. 1×10~(-3)μm~2;Ⅲ级裂缝线密度为1. 00条/m,平均有效开度为0. 4 mm,渗透率为5. 3×10~(-3)μm~2;Ⅳ级裂缝线密度小于1. 00条/m,平均有效开度为25. 0μm,渗透率仅约为1. 3×10~(-6)μm~2,对提高储层渗透率的贡献较小。依据裂缝渗透率的计算公式,结合不同尺度裂缝线密度、有效开度与渗透率的对比表明,裂缝线密度与产能并不一定成正比,裂缝有效开度对产能的影响更大,因此,在裂缝性储层评价中应将裂缝有效开度作为一个重要参数。克深5气藏背斜西侧裂缝充填程度较高,有效开度较小,产能较低;而背斜东侧的裂缝充填程度较低,有效开度较大,产能较高,应作为后续开发井部署的重点区域。研究结论可为克深5气藏开发井位的部署提供地质依据。
In order to clarify the penetration of multi-scale fractures and its influence on natural gas development,the fractures of Keshen5 gas reservoir in Kuqa Depression are classified into four levels. The permeability of each level fracture is calculated,and the effects of line fracture density and fracture aperture on productivity are analyzed to determine the favorable zone for well deployment. Research indicates that the line density of Level-Ⅰ fracture is 0.10 per meter,the average fracture aperture is 1.0 ~ 3.0 cm,the fracture permeability is 8 300.0× 10~(-3)~ 225 000.0× 10~(-3)μm~2. The line density of Level-Ⅱ fracture is 0.21 per meter,the average fracture aperture is 1.5 mm,the fracture permeability is 59.1×10~(-3)μm~2. The line density of Level-Ⅲ fracture is 1.00 Per meter,the average fracture aperture is 0.4 mm,the fracture permeability is 5.3×10~(-3)μm~2. The line density of Level-Ⅳ fracture is 1.00 per meter,the average fracture aperture is 25 μm,the fracture permeability is 1.3×10~(-6)μm~2,which shows less contribution to reservoir permeability. According to the fracture permeability calculation equation and the comparison of line density and permeability,the fracture line density is not necessarily proportional to productivity and the productivity is more dependent on the fracture aperture. Therefore,the fracture aperture should be taken as a key parameter in fractured reservoir evaluation. The fractures in the west side of Keshen5 gas reservoir anticline are characterized by low fillinglevel and less effective aperture,which results in low production. The fractures in the east side of the anticline are characterized by low filling level and high fracture aperture,which indicates high productivity and should be taken as a favorable area for the subsequent well deployment. This research could provide certain geological basis for the development well deployment in the Keshen5 gas reservoir.
In order to clarify the penetration of multi-scale fractures and its influence on natural gas development,the fractures of Keshen5 gas reservoir in Kuqa Depression are classified into four levels. The permeability of each level fracture is calculated,and the effects of line fracture density and fracture aperture on productivity are analyzed to determine the favorable zone for well deployment. Research indicates that the line density of Level-Ⅰ fracture is 0.10 per meter,the average fracture aperture is 1.0 ~ 3.0 cm,the fracture permeability is 8 300.0× 10~(-3)~ 225 000.0× 10~(-3)μm~2. The line density of Level-Ⅱ fracture is 0.21 per meter,the average fracture aperture is 1.5 mm,the fracture permeability is 59.1×10~(-3)μm~2. The line density of Level-Ⅲ fracture is 1.00 Per meter,the average fracture aperture is 0.4 mm,the fracture permeability is 5.3×10~(-3)μm~2. The line density of Level-Ⅳ fracture is 1.00 per meter,the average fracture aperture is 25 μm,the fracture permeability is 1.3×10~(-6)μm~2,which shows less contribution to reservoir permeability. According to the fracture permeability calculation equation and the comparison of line density and permeability,the fracture line density is not necessarily proportional to productivity and the productivity is more dependent on the fracture aperture. Therefore,the fracture aperture should be taken as a key parameter in fractured reservoir evaluation. The fractures in the west side of Keshen5 gas reservoir anticline are characterized by low fillinglevel and less effective aperture,which results in low production. The fractures in the east side of the anticline are characterized by low filling level and high fracture aperture,which indicates high productivity and should be taken as a favorable area for the subsequent well deployment. This research could provide certain geological basis for the development well deployment in the Keshen5 gas reservoir.
引文
[1]戴金星,倪云燕,吴小奇.中国致密砂岩气及在勘探开发上的重要意义[J].石油勘探与开发,2012,39(3):257-264.
[2]张茜,孙卫,杨晓菁,等.致密砂岩储层差异性成岩演化对孔隙度演化定量表征的影响:以鄂尔多斯盆地华庆地区长63储层为例[J].石油实验地质,2017,39(1):126-133.
[3] UKAR E,OZKUL C,EICHHUBL P. Fracture abundance and strain in folded Cardium Formation,Red Deer River anticline,Alberta Foothills,Canada[J]. Marine and Petroleum Geology,2016,76:210-230.
[4]方思冬,程林松,李彩云,等.应力敏感油藏多角度裂缝压裂水平井产量模型[J].东北石油大学学报,2015,39(1):87-94.
[5]曾联波,漆家福,王永秀.低渗透储层构造裂缝的成因类型及其形成地质条件[J].石油学报,2007,28(4):52-56.
[6]刘冬冬,张晨,罗群,等.准噶尔盆地吉木萨尔凹陷芦草沟组致密储层裂缝发育特征及控制因素[J].中国石油勘探,2017,22(4):36-47.
[7]吴国强,张丽娟,杨振周,等.塔里木盆地哈拉哈塘地区奥陶系储层古岩溶作用及其与裂缝的关系[J].石油实验地质,2017,39(6):790-796.
[8]范存辉,王彭,秦启荣,等.松辽盆地杏树岗油田低渗透储层裂缝发育特征[J].特种油气藏,2013,20(3):36-40.
[9]关宝文,郭建明,杨燕,等.油气储层裂缝预测方法及发展趋势[J].特种油气藏,2014,21(1):12-17.
[10]黎静容,朱桦,冯晓明,等.川东北陆相储层裂缝特征差异性及对产能的影响[J].石油实验地质,2016,38(6):742-747.
[11]冯洁,宋岩,姜振学,等.塔里木盆地克深区巴什基奇克组砂岩成岩演化及主控因素[J].特种油气藏,2017,24(1):70-75.
[12]VAN GOLF-RACHT T D.裂缝性油藏工程基础[M].陈钟祥,金玲年,秦同洛,译.北京:石油工业出版社,1989:31-40.
[13]吴胜和.储层表征与建模[M].北京:石油工业出版社,2010:269-272.
[2]张茜,孙卫,杨晓菁,等.致密砂岩储层差异性成岩演化对孔隙度演化定量表征的影响:以鄂尔多斯盆地华庆地区长63储层为例[J].石油实验地质,2017,39(1):126-133.
[3] UKAR E,OZKUL C,EICHHUBL P. Fracture abundance and strain in folded Cardium Formation,Red Deer River anticline,Alberta Foothills,Canada[J]. Marine and Petroleum Geology,2016,76:210-230.
[4]方思冬,程林松,李彩云,等.应力敏感油藏多角度裂缝压裂水平井产量模型[J].东北石油大学学报,2015,39(1):87-94.
[5]曾联波,漆家福,王永秀.低渗透储层构造裂缝的成因类型及其形成地质条件[J].石油学报,2007,28(4):52-56.
[6]刘冬冬,张晨,罗群,等.准噶尔盆地吉木萨尔凹陷芦草沟组致密储层裂缝发育特征及控制因素[J].中国石油勘探,2017,22(4):36-47.
[7]吴国强,张丽娟,杨振周,等.塔里木盆地哈拉哈塘地区奥陶系储层古岩溶作用及其与裂缝的关系[J].石油实验地质,2017,39(6):790-796.
[8]范存辉,王彭,秦启荣,等.松辽盆地杏树岗油田低渗透储层裂缝发育特征[J].特种油气藏,2013,20(3):36-40.
[9]关宝文,郭建明,杨燕,等.油气储层裂缝预测方法及发展趋势[J].特种油气藏,2014,21(1):12-17.
[10]黎静容,朱桦,冯晓明,等.川东北陆相储层裂缝特征差异性及对产能的影响[J].石油实验地质,2016,38(6):742-747.
[11]冯洁,宋岩,姜振学,等.塔里木盆地克深区巴什基奇克组砂岩成岩演化及主控因素[J].特种油气藏,2017,24(1):70-75.
[12]VAN GOLF-RACHT T D.裂缝性油藏工程基础[M].陈钟祥,金玲年,秦同洛,译.北京:石油工业出版社,1989:31-40.
[13]吴胜和.储层表征与建模[M].北京:石油工业出版社,2010:269-272.