杭锦旗地区中晚元古界油气地质特征与勘探潜力分析
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摘要
杭锦旗地区是鄂尔多斯盆地的一个重要勘探区块,元古界是该区有油气藏发现的一个全新的勘探目的层。参考了前人的地层划分方案,将工区内的地层展开对比,统一了工区内钻井的分层方案;明确了各地层层系的展布趋势;追踪解释了杭锦旗地区T_9、T_(12)、T_(13)、T_g等的地震反射层位;制作了相应各层的视铅垂深度构造图、沉积厚度图等图件;假定沉积厚度受古构造升降格局所控制,分析了杭锦旗地区的元古界古构造面貌与演化;根据该区所提取的地震属性以及野外露头及钻井岩心的总结和分析,得出了该区的主要的沉积特征。并根据古构造演化和今构造特征与油气运聚散的关系,及烃源岩等有利成藏条件,指出了该区几个主要油气聚集带。
杭锦旗地区中元古界在地震剖面上表现为断陷层和坳陷层,二者之间为角度不整合(地震波组T_(13))。坳陷层夹白云岩的特点可与露头区的中元古界蓟县系对比,覆盖区的断陷层的时代为贺兰山的长城系,坳陷层则相当于贺兰的蓟县系。断陷层分布局限,主要为扇三角洲粗砂岩、细砾岩局部夹-浅海陆棚灰色泥岩沉积。坳陷层分布广泛,工区内接近边缘相,为扇三角洲杂色砂岩、细砾岩夹褐色泥岩、碳酸盐岩,向西逐渐变为潮坪和开阔台地。
杭锦旗地区元古界的砂岩普遍发育。岩性主要为不同粒级的岩屑砂岩、石英砂岩、长石砂岩。孔隙类型主要以残余粒间孔和次生溶孔为主,局部发育裂缝。储层整体属于低孔-低渗、低孔-特低渗型储层。
中元古界地层的古构造演化和今构造特征,指示了该区的古构造演化与油气运移路径、方向、聚集和散失的关系。参考了关于该区烃源岩生烃的研究成果,考虑到生储盖等条件,确定了锦3井和石鄂2井连线附近及其北西地区、鄂2井西的地势由陡变缓的转折区带的裂缝储层发育区以及锦13井以东的断裂与断裂交汇处三个有利油气聚集区。
Hang Jinqi area is an important exporation area in Ordos Basin. In this area Proterozoic is a new exporation target. Referred to previous work, author traced horizon of T_9、T_(12)、T_(13)、T_g in Hang Jinqi area, and made up apparent-plumb depth maps and deposition thickness maps by using the LandMark workstation. Assuming the deposition thickness is dominated by palaeostructure elevation and subsidence framework, writer analyze Proterozoic palaeostructure feature. On the basis of relationship of palaeostructure evolution and the present structural feature togethered with hydrocarbon migration and accumulation and the source rock, writer pointed out several main oil and gas accumulation zones in Hang Jinqi area.
According to the seismic cross section, the Proterozoic group is made up of the fault depression layer and the sag layer in Hang Jinqi area. The relationship of contact is angle disconformity. According to the imbedded dolomitic, the sag layer can be compaired with Jixian system, the fault depression layer can compaired with Changcheng system. The distribution of fault depression layer is restricted. The dominant sediments are greet stone, microconglomerate and partly clip gray clay stone. The sag layer widely distribute. It's border facies closely. The dominant sediments are variegated sandstone, microconglomerate and partly clip brown clay stone and carbonatite. Westward it turns into tital flat and open platform.
The sandstone in Proterozoic group is developed universally. Lithologic character is lithic sandstone, quartz sandstone and feldspar-porphyry sandstone. The type of porosity mainly contains the remain intergranular porosity and the secondary dissolved pore, partly develop fissure. It belongs to the low porosity and low permeability reservoir and low porosity and particularly low permeability reservoir.
Proterozoic palaeostructure evolution and the present structural feature indicates the relationship of the palaeostructure evolution and hydrocarbon migration, direction, accumulation and dissipate. Referring to previous work that the hydrocarbon source rock have hydrocarbon-expulsion, and the factor, meanwhile, thought of the conditions of translocating system and source reservoir cap assemblage, author forecasted three oil and gas accumulation zones, which are The west of Shie2 well-block, Shie2-Jin3 well-blocks and Jin13 well-blocks.
杭锦旗地区中元古界在地震剖面上表现为断陷层和坳陷层,二者之间为角度不整合(地震波组T_(13))。坳陷层夹白云岩的特点可与露头区的中元古界蓟县系对比,覆盖区的断陷层的时代为贺兰山的长城系,坳陷层则相当于贺兰的蓟县系。断陷层分布局限,主要为扇三角洲粗砂岩、细砾岩局部夹-浅海陆棚灰色泥岩沉积。坳陷层分布广泛,工区内接近边缘相,为扇三角洲杂色砂岩、细砾岩夹褐色泥岩、碳酸盐岩,向西逐渐变为潮坪和开阔台地。
杭锦旗地区元古界的砂岩普遍发育。岩性主要为不同粒级的岩屑砂岩、石英砂岩、长石砂岩。孔隙类型主要以残余粒间孔和次生溶孔为主,局部发育裂缝。储层整体属于低孔-低渗、低孔-特低渗型储层。
中元古界地层的古构造演化和今构造特征,指示了该区的古构造演化与油气运移路径、方向、聚集和散失的关系。参考了关于该区烃源岩生烃的研究成果,考虑到生储盖等条件,确定了锦3井和石鄂2井连线附近及其北西地区、鄂2井西的地势由陡变缓的转折区带的裂缝储层发育区以及锦13井以东的断裂与断裂交汇处三个有利油气聚集区。
Hang Jinqi area is an important exporation area in Ordos Basin. In this area Proterozoic is a new exporation target. Referred to previous work, author traced horizon of T_9、T_(12)、T_(13)、T_g in Hang Jinqi area, and made up apparent-plumb depth maps and deposition thickness maps by using the LandMark workstation. Assuming the deposition thickness is dominated by palaeostructure elevation and subsidence framework, writer analyze Proterozoic palaeostructure feature. On the basis of relationship of palaeostructure evolution and the present structural feature togethered with hydrocarbon migration and accumulation and the source rock, writer pointed out several main oil and gas accumulation zones in Hang Jinqi area.
According to the seismic cross section, the Proterozoic group is made up of the fault depression layer and the sag layer in Hang Jinqi area. The relationship of contact is angle disconformity. According to the imbedded dolomitic, the sag layer can be compaired with Jixian system, the fault depression layer can compaired with Changcheng system. The distribution of fault depression layer is restricted. The dominant sediments are greet stone, microconglomerate and partly clip gray clay stone. The sag layer widely distribute. It's border facies closely. The dominant sediments are variegated sandstone, microconglomerate and partly clip brown clay stone and carbonatite. Westward it turns into tital flat and open platform.
The sandstone in Proterozoic group is developed universally. Lithologic character is lithic sandstone, quartz sandstone and feldspar-porphyry sandstone. The type of porosity mainly contains the remain intergranular porosity and the secondary dissolved pore, partly develop fissure. It belongs to the low porosity and low permeability reservoir and low porosity and particularly low permeability reservoir.
Proterozoic palaeostructure evolution and the present structural feature indicates the relationship of the palaeostructure evolution and hydrocarbon migration, direction, accumulation and dissipate. Referring to previous work that the hydrocarbon source rock have hydrocarbon-expulsion, and the factor, meanwhile, thought of the conditions of translocating system and source reservoir cap assemblage, author forecasted three oil and gas accumulation zones, which are The west of Shie2 well-block, Shie2-Jin3 well-blocks and Jin13 well-blocks.
引文
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[3]妥进才,王先彬.深层油气和非生物成因天然气的耦合与差异[J].天然气地球化学.2006,2(1):36-41
[4]丁燕云.鄂尔多斯盆地北部航磁反映的构造特征[J].物探和化探.2000,24(3):197-202
[5]何自新.鄂尔多斯盆地演化与油气[M].北京:石油工业出版社,2003
[6]长庆油田石油地质志编写组.中国石油地质志[M].北京:石油工业出版社,1992
[7]杨俊杰,裴锡古.中国天然气地质学 第四卷 鄂尔多斯盆地[M].北京:石油工业出版社,1996
[8]国家地质总局西安地质矿产研究所前寒武纪组.宁夏贺兰山区震旦亚界[J].西北地质.1978:6-18
[9]何樵登等.地震勘探原理和方法[M].地质出版社,1986
[10]陆基孟.地震勘探原理[M].东营:石油大学出版社,1993:75-76
[11]靳玲,苏桂芝等.合成地震记录制作的影响因素及对策[J].石油勘探.2004,43(3):267-274
[12]陈裕明,李晶,周亚同.合成地震记录的改进方法讨论[J].石油地球物理勘探.2001,36(4):495-498
[13]蒲仁海,卢金诚.鄂尔多斯盆地华力西期、加里东期构造层地质构造研究与工业制图[R].西安:西北大学,1996
[14]吴紫电,王大兴.鄂尔多斯盆地北部古生界构造研究[R].西安:长庆石油勘探局地球物理勘探处研究队,1990
[15]姚宗惠,张明山,曾令邦等.鄂尔多斯盆地北部断裂分析[J].石油勘探与开发.2003,30(2):20-23
[16]吴紫电,卢金城,刘运睦.鄂尔多斯盆地中南部地震区域构造及古构造演化[R].西安:长庆石油勘探局物理勘探处研究队,1993
[17]张军,王乐,李开富.鄂尔多斯盆地西部逆冲推覆构造带专题研究报告集[R].西安: 长庆石油勘探局勘探开发研究院,西北大学地质系,1986
[18]郭忠铭,王定一,汤锡元.鄂尔多斯盆地西部逆冲推覆构造特征及油气勘探[R].西安:长庆石油勘探局勘探开发研究院,西北大学地质系,1986
[19]赵重远,刘池洋,姚远.含油气盆地地质学进展[M].西安:西北大学出版社,1993:3-8。
[20]赵重远,张小会,等.油气成藏动态预测[J].石油与天然气地质.2002,23(4):314-319。
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