鄂尔多斯盆地安塞油田长6储层微观孔隙结构
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摘要
利用铸体薄片、扫描电镜、恒速压汞、核磁共振、真实砂岩微观驱替实验等测试手段,对安塞油田长6特低渗透储层微观孔隙结构、可动流体饱和度特征进行了研究。结果表明:粒间孔对可动流体饱和度具有较大的贡献,溶蚀孔不利于可动流体的赋存,喉道大小、孔喉比、分选系数对可动流体饱和度影响大,而储层物性、面孔率、孔隙半径的影响微乎其微。利用真实砂岩微观驱替型实验得到:不同物性样品的驱替类型及驱油效率存在明显差异。渗透率大于1.0×10-3μm2的样品,孔隙类型为溶孔-粒间孔型,驱替类型为网状-均匀驱替,最终驱油效率为69.3%;渗透率0.5×10-3~1.0×10-3μm2的样品,孔隙类型为粒间孔-溶孔型,驱替类型为指状-网状驱替,最终驱油效率为43.8%;渗透率小于0.5×10-3μm2的样品,孔隙类型为微孔-溶孔型,驱替类型为指状驱替,最终驱油效率为32.9%。
In this paper, microscopic pore structure and movable fluid saturation characteristics of Chang 6 ultra-low permeability reservoir in Ansai Oilfield are studied by means of casting thin slices, scanning electron microscopy, constant pressure mercury intrusion, nuclear magnetic resonance, and real sandstone microscopic model. The results show that the content of intergranular pores has a good contribution to the saturation of the movable fluid, while the content of the dissolved pores is unfavorable to the occurrence of the movable fluid; throat size, pore throat ratio, sorting coefficient have a great influence on mobile fluid saturation,otherwise reservoir physical properties, porosity, pore radius do less. Real sandstone micro-displacement experiment shows that the displacement path and oil displacement efficiency of the samples with different physical properties are obviously different. The samples with permeability greater than 1.0×10-3μm2 are of pores-intergranular pore type and the type of displacement is net-uniform displacement with final flooding efficiency 69.3%. The samples with permeability from 0.5 ×10-3 to 1.0×10-3μm2, the type of pores are dissolved pores-intergranular pore type, the displacement type is finger-net displacement with displacement efficiency 43.8%.The samples with permeability less than 0.5 ×10-3μm2 have micropore-dissolution pore type and displacement type are fingerdisplacement with final displacement efficiency 32.9%.
In this paper, microscopic pore structure and movable fluid saturation characteristics of Chang 6 ultra-low permeability reservoir in Ansai Oilfield are studied by means of casting thin slices, scanning electron microscopy, constant pressure mercury intrusion, nuclear magnetic resonance, and real sandstone microscopic model. The results show that the content of intergranular pores has a good contribution to the saturation of the movable fluid, while the content of the dissolved pores is unfavorable to the occurrence of the movable fluid; throat size, pore throat ratio, sorting coefficient have a great influence on mobile fluid saturation,otherwise reservoir physical properties, porosity, pore radius do less. Real sandstone micro-displacement experiment shows that the displacement path and oil displacement efficiency of the samples with different physical properties are obviously different. The samples with permeability greater than 1.0×10-3μm2 are of pores-intergranular pore type and the type of displacement is net-uniform displacement with final flooding efficiency 69.3%. The samples with permeability from 0.5 ×10-3 to 1.0×10-3μm2, the type of pores are dissolved pores-intergranular pore type, the displacement type is finger-net displacement with displacement efficiency 43.8%.The samples with permeability less than 0.5 ×10-3μm2 have micropore-dissolution pore type and displacement type are fingerdisplacement with final displacement efficiency 32.9%.
引文
[1]朱玉双,吴长辉.鄂尔多斯盆地杏北区长6储层特征及影响因素分析[J].西北大学学报(自然科学版),2010,40(3):498-502.
[2]张庆,朱玉双.杏北区长6储层非均质性对含油性分布的影响[J].西北大学学报(自然科学版),2009,39(2):277-282.
[3]郑艳荣,屈红军.安塞油田H区长6油层组储层微观孔隙结构特征[J].岩性油气藏,2011,23(5)29-32.
[4]全洪慧,朱玉双,张洪军,等.储层孔隙结构与水驱油微观渗流特征[J].石油与天然气地质,2011,32(54):952-959.
[5]朱玉双,曲志浩,孔令荣,等.安塞油田坪桥区、王窑区长6油层储层特征及驱油效率分析[J].沉积学报,2000,18(2):279-283.
[6]朱玉双,孔令荣,曲志浩,等.注水开发并非安塞油田长6油层低采收率的主要原因[J].石油与天然气地质,1997,18(3):221-223.
[7]孙卫.安塞油田长6油层微观模型化学堵水实验[J].石油与天然气地质,1997,18(3):199-203.
[8]周科平,李杰林,许玉娟,等.基于核磁共振技术的岩石孔隙结构特征测定[J].中南大学学报(自然科学版),2012,43(12):4796-4800.
[9]宋广寿,高辉,高静乐,等.西峰油田长8储层微观孔隙结构非均质性与渗流机理试验[J].吉林大学学报(地球科学版),2009,39(1):53-58.
[10]高永利,张志国.恒速压汞技术定量评价低渗透砂岩孔喉结构差异[J].地质科技情报,2011,30(4):73-76.
[11]郝乐伟,王琪,唐俊,等.储层岩石微观孔隙结构研究方法与理论综述[J].岩性油气藏,2013,25(5):123-128.
[12]何涛,王芳,汪伶俐,等.致密砂岩储层微观孔隙结构特征:以鄂尔多斯盆地延长组长7储层为例[J].岩性油气藏,2013,25(4):23-26.
[13]王瑞飞,陈明强.特低渗透砂岩储层可动流体赋存特征及影响因素[J].石油学报,2008,29(4):558-561.
[14]雷启鸿,孙华岭,李晶,等.长庆低渗透储层可动流体饱和度评价[J].低渗透油气田,2006,11(1):94-97.
[2]张庆,朱玉双.杏北区长6储层非均质性对含油性分布的影响[J].西北大学学报(自然科学版),2009,39(2):277-282.
[3]郑艳荣,屈红军.安塞油田H区长6油层组储层微观孔隙结构特征[J].岩性油气藏,2011,23(5)29-32.
[4]全洪慧,朱玉双,张洪军,等.储层孔隙结构与水驱油微观渗流特征[J].石油与天然气地质,2011,32(54):952-959.
[5]朱玉双,曲志浩,孔令荣,等.安塞油田坪桥区、王窑区长6油层储层特征及驱油效率分析[J].沉积学报,2000,18(2):279-283.
[6]朱玉双,孔令荣,曲志浩,等.注水开发并非安塞油田长6油层低采收率的主要原因[J].石油与天然气地质,1997,18(3):221-223.
[7]孙卫.安塞油田长6油层微观模型化学堵水实验[J].石油与天然气地质,1997,18(3):199-203.
[8]周科平,李杰林,许玉娟,等.基于核磁共振技术的岩石孔隙结构特征测定[J].中南大学学报(自然科学版),2012,43(12):4796-4800.
[9]宋广寿,高辉,高静乐,等.西峰油田长8储层微观孔隙结构非均质性与渗流机理试验[J].吉林大学学报(地球科学版),2009,39(1):53-58.
[10]高永利,张志国.恒速压汞技术定量评价低渗透砂岩孔喉结构差异[J].地质科技情报,2011,30(4):73-76.
[11]郝乐伟,王琪,唐俊,等.储层岩石微观孔隙结构研究方法与理论综述[J].岩性油气藏,2013,25(5):123-128.
[12]何涛,王芳,汪伶俐,等.致密砂岩储层微观孔隙结构特征:以鄂尔多斯盆地延长组长7储层为例[J].岩性油气藏,2013,25(4):23-26.
[13]王瑞飞,陈明强.特低渗透砂岩储层可动流体赋存特征及影响因素[J].石油学报,2008,29(4):558-561.
[14]雷启鸿,孙华岭,李晶,等.长庆低渗透储层可动流体饱和度评价[J].低渗透油气田,2006,11(1):94-97.