库车坳陷逆掩断层封闭性及流体运移
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摘要
本文通过逆掩断层发育特征研究，分析了逆掩断层封闭机理，在断裂带填充物性质与断层封闭性定量关系模拟实验和膏泥岩变形特征模拟实验基础上建立了断层封闭性评价标准及评价方法，以此对库车坳陷几个典型构造上逆掩断层垂向封闭性进行了评价，结果表明现今断层多是封闭的，这是库车塌陷天然气和异常孔隙流体压力得以保存的主要条件。利用生长三角带和平衡剖面技术对断裂形成时期和活动时期进行了研究，结果表明，不同构造带断裂形成时期存在很大差异，基本规律是从北到南断裂形成时间越来越晚，但断裂主要活动时期则在库车期—第四系。在此基础上对逆掩断层垂向封闭性演化史进行了恢复，认为断裂自吉迪克组沉积时期以来均有活动，但这种活动是间歇性的，活动时期断层开启，静止时期断层多是封闭的。建立了逆掩断层泄压的地质模型和数学模型，选取参数后进行了模拟计算，结果表明逆掩断层活动开启释放压力，但要将地层压力释放到正常地层压力需要时间较长，在断裂活动时期不足以将圈闭中超压释放掉，这是库车坳陷超压能够保存的另一主要原因。分析了断裂在天然气成藏中的作用，认为不同类型的断裂在天然气成藏过程中的作用是不同的：贯通生、储、盖层的穿盐断层对油气散失和泄压作用；贯通源岩和储层的盐下断层对抽气运聚的充注作用；不连接源岩的滑脱断层对油气聚散无作用；储层内调整断层对油气分布起调整层位作用。总结了库车坳陷存在的四种断层组合输导模式：即盐下断层通过断层与穿盐断裂相连的组合输导模式；盐下断层通过储层与穿盐断裂相连的组合输导模式；盐下断裂通过储层和圈闭顶部突破断层与穿盐断裂相连的组合输导模式；单一穿盐断层输导模式。并利用该模式对库车坳陷几个典型构造天然气成藏过程进行了研究，并对失利井进行了分析，结果认为第一种和第二种模式有利于天然气藏形成，第三种模式因圈闭顶部发育突破断层不会形成大气田，第四种模式因缺乏天然气充注通道很难形成气藏。在此基础上分析了库车坳陷天然气成藏特征，总结出三种天然气成藏模式，即克拉2型成藏模式、克拉3型成藏模式和吐孜洛克型成藏模式。该模式对库车坳陷下一步勘探具有重要指导作用。
Through the research on the development character of overthrust fault, we analyzed its sealing mechanism. We also established evaluation standard and method of fault sealing ability through the following two simulation experiment: experiment on the quantitative relationship between property of fracture zone filler and fault sealing ability; experiment on the deformation character of cream shale. Based on these work, we evaluated sealing ability of overthrust faults on several typical structure in Kuche depression. The result is that most current faults are sealed. This is the main condition for natural gas and abnormal pore pressure to preserve in Kuche depression. We have also studied fracture formation and moving period by means of growth triangle zone and equilibrium section technology. The result is that fracture formation period in diffirentt struture zone are very d'rffirent. The basic law is that from the north to the south, the fracture formation period is later and later. But the main fracture moving period is Kuche - Quaternary. Based on these research, we recovered the evolution history of overthrust faults vertical sealing ability and considered that there always have fracture activity ever since Jidike formation deposition period. But this kind of activity is not always continuous. During moving period, fault is open. During static period, fault is dosed. We established geological and mathematic model for the relief of overthrust fault and earned out simulation computation after selecting factors. The result is that pressure can be released when fault is open. But ft will take a long time for the formation pressure to be relieved to normal formation pressure. This is not enough for the superpressure in the trap to be relieved. This is the other main reason for the overpressure in Kuche depression to be preserved. We analyzed the effect of fracture in the gas deposit formation and hold that different kinds of fracture have different effect: hydrocarbon dissipation and relief effect of crossing salt bed faults that run through source rock, reservoir, and caprock; filling effect of under salt bed faults that run through source rock and reservoir; slippage faults that did not connect source rock have no effect to hydrocarbon accumulation and dissipation; adjusting faults in reservoir have effect of adjusting formations for hydrocarbon distribution. We also summed up four kinds of faults combination transportation model: the model that under salt bed fault and crossing salt bed fault are connected by faults; the model that under salt bed fault and crossing salt bed fault are connected by reservoir, the model that under salt bed fracture and crossing salt bed fracture are connected by reservoir and breakthrough faults at the top of the trap; single crossing salt bed model. We studied gas deposit formation process of several typical structure in Kuche depression by these models. Failure wells were also analyzed. The result is that the first and second model are favorable to gas deposits formation. The third model can not form
big gas deposit because breakthrough faults developed at the top of the trap. The fourth model are very drfficuft to form gas deposit because the short of gas filing passage. Based on these research, we analyzed gas deposit formation character of Kuche depression and concluded three kinds of gas deposit formation model. They are: Kela 2 model, Kela 3 model; Tuzfluoke model. The models are important guide for next step exploration in Kuche depression.
Through the research on the development character of overthrust fault, we analyzed its sealing mechanism. We also established evaluation standard and method of fault sealing ability through the following two simulation experiment: experiment on the quantitative relationship between property of fracture zone filler and fault sealing ability; experiment on the deformation character of cream shale. Based on these work, we evaluated sealing ability of overthrust faults on several typical structure in Kuche depression. The result is that most current faults are sealed. This is the main condition for natural gas and abnormal pore pressure to preserve in Kuche depression. We have also studied fracture formation and moving period by means of growth triangle zone and equilibrium section technology. The result is that fracture formation period in diffirentt struture zone are very d'rffirent. The basic law is that from the north to the south, the fracture formation period is later and later. But the main fracture moving period is Kuche - Quaternary. Based on these research, we recovered the evolution history of overthrust faults vertical sealing ability and considered that there always have fracture activity ever since Jidike formation deposition period. But this kind of activity is not always continuous. During moving period, fault is open. During static period, fault is dosed. We established geological and mathematic model for the relief of overthrust fault and earned out simulation computation after selecting factors. The result is that pressure can be released when fault is open. But ft will take a long time for the formation pressure to be relieved to normal formation pressure. This is not enough for the superpressure in the trap to be relieved. This is the other main reason for the overpressure in Kuche depression to be preserved. We analyzed the effect of fracture in the gas deposit formation and hold that different kinds of fracture have different effect: hydrocarbon dissipation and relief effect of crossing salt bed faults that run through source rock, reservoir, and caprock; filling effect of under salt bed faults that run through source rock and reservoir; slippage faults that did not connect source rock have no effect to hydrocarbon accumulation and dissipation; adjusting faults in reservoir have effect of adjusting formations for hydrocarbon distribution. We also summed up four kinds of faults combination transportation model: the model that under salt bed fault and crossing salt bed fault are connected by faults; the model that under salt bed fault and crossing salt bed fault are connected by reservoir, the model that under salt bed fracture and crossing salt bed fracture are connected by reservoir and breakthrough faults at the top of the trap; single crossing salt bed model. We studied gas deposit formation process of several typical structure in Kuche depression by these models. Failure wells were also analyzed. The result is that the first and second model are favorable to gas deposits formation. The third model can not form
big gas deposit because breakthrough faults developed at the top of the trap. The fourth model are very drfficuft to form gas deposit because the short of gas filing passage. Based on these research, we analyzed gas deposit formation character of Kuche depression and concluded three kinds of gas deposit formation model. They are: Kela 2 model, Kela 3 model; Tuzfluoke model. The models are important guide for next step exploration in Kuche depression.
引文
1．张明山．库车陆内前陆盆地构造变形和油气地质综合分析．中国地质大学博士后研究出站报告，1998，中国地质大学
2．高增海，李洪革，张承元等．库车坳陷构造特征及油气聚集规律．物探局研究院地研中心，2000
3．田作基，邹华耀．库车坳陷油气藏形成条件及油气分布规律．塔里木油田分公司勘探事业部，江汉石油学院地质系，2000
4．田军等．塔北隆起及库车坳陷勘探目标选择与评价．塔里木石油勘探开发指挥部勘探研究中心，石油物探局库尔勒物探研究中心，石油物探局三处地质研究所，西安石油学院石油天然气地质研究所，1998
5．赵孟军，卢双舫，王廷栋等．塔里木盆地天然气成藏条件及勘探方向．中国石油勘探开发研究院，塔里木油田分公司，大庆石油学院，2000
6．顾家裕等．库车前陆盆地演化与油气资源评价．塔里木石油勘探开发指挥部，北京石油勘探开发科学研究院，1999
7．周兴熙等．塔里木盆地天然气形成条件及分布规律．北京石油勘探开发科学研究院，1995
8.Smith D A. Theoretical consideration of sealing and non-sealing faults.AAPG.,1966,50:363～374
9.Engelder J T.Cataclasis and the generation of fault gouge. Geological society of American Bulletin,1974,85:1515～1522
10.Weber K J et al.The role of faults in hydrocarbon migration and trapping in Nigerian growth fault structures. Tenth Annual offshore Technology conference proceedings.1978,4:2643～2653
11.Harding T P and Tuminas A C.Structural interpretation of hydrocarbon traps sealed by basement normal blocks and at stable flank of foredeep basins and at rift basins.AAPG.,1989,73:812～840
12.Allan U S.Model for hydrocarbon migtation and entrapment within faulted.AAPG Bulletin.1989,73:803～811
13.Bouvier J D.Three-dimensional seismic interpretation and fault sealing investigation,Nun River Field,Nigeria.AAPG.,1989,11:1397～1411
14.Harding T P and Tnminas A C.Structural interpretation of hydrocarbon traps sealed by basement normal blocks and at stable flank of foredeep basins and at rift basins.AAPG.,1989,73:812～840
15.Knipe R J.Faulting process and fault seal.NPF special publication,1992,(1):325～342
16.Knott S D.Fault seal analysis in the North sea.AAPG.,1993,77:778～792
17.Jev B I et al.Akaso field,Nigeria:use of intergrated 3-D seismic,fault slicing,clay smearing,and RFT pressure data on fault trapping and dynamic leakage.AAPG.,1993,77:1389～1404
18.Gibson R G.Fault zone seals in siliclastic strata of the Columbus Basin,offshore Trinidad.AAPG.,1994,78
19.Robert D and Hatcher Jr.Structural geology,principles,concepts,and problems,second edition.New Jersy:Prentice-Hall Inc,1995
20.Knipe R J.Juxtaposition and seal diagrams to help analyze fault seals in hydrocabon reservoirs.AAPG.,1997,81(2): 187～195
21.Yielding G,Freeman B and Needham D T.Quantitive fault seal predication.AAPG.,1997,81(6):917～987
22．曹瑞成，陈章明．早期探区封闭性评价方法．石油学报，1992，13：33～37
23．孙宝珊，周新桂，邵兆刚．油田断裂封闭与通道作用研究．地质力学学报，1995，2(2)：1～7
24．吕延防．断层封闭性的定量研究方法．石油学报，1996，17：39～43
25．鲁兵，陈章明等．断面活动特征及其对油气的封闭作用．石油学报，1996，17：33～37
26．周新桂．利用排驱压力研究断裂封闭性及其在塔里木盆地北部地区的应用．地质力学学报，1997，3(2)：47～53
27．王志欣，信荃麟．关于地下断层封闭性讨论(以东营凹陷为例)．高校地质学报，1997，3(3)：294～300
28．白新华．浅析断裂活动对火山油气藏形成的控制作用．特种油气藏，1999，6(1)：6～9
29．付广，李风君，白明轩．断层侧向封闭性与垂向封闭性关系分析．大庆石油地质与开发，1998，17(2)：6～9
30．李亚辉，刘泽容，陈利．断裂封闭演化史研究方法及其应用．石油大学学报，1998，22(3)：15～18
31．童亨茂，李德同．应力对流体及其油气二次运移作用的几种模式．石油大学学报，1998，23(2)：14～17
32．邹华耀，金燕．断层封闭与油气运移和聚集．江汉石油学院学报，1999，2(1)：9～12
33．谯汉生，牛嘉玉，王明明．中国东部深部层系反向断层遮挡聚油原理与勘探实践．1999，26(6)：10～13
34．鲁兵，孔宪政等．断块结构与断块封闭性间的关系．石油勘探与开发，1999，26(6)：14～17
35．阎福礼，贾东等．油气运移的断层封闭因素探讨．江苏地质，2000，24(2)：95～100
36．付广，杨勉．利用地震资料判断断层封闭性的方法探讨．石油物探，2000，39(1)：70-76
2．高增海，李洪革，张承元等．库车坳陷构造特征及油气聚集规律．物探局研究院地研中心，2000
3．田作基，邹华耀．库车坳陷油气藏形成条件及油气分布规律．塔里木油田分公司勘探事业部，江汉石油学院地质系，2000
4．田军等．塔北隆起及库车坳陷勘探目标选择与评价．塔里木石油勘探开发指挥部勘探研究中心，石油物探局库尔勒物探研究中心，石油物探局三处地质研究所，西安石油学院石油天然气地质研究所，1998
5．赵孟军，卢双舫，王廷栋等．塔里木盆地天然气成藏条件及勘探方向．中国石油勘探开发研究院，塔里木油田分公司，大庆石油学院，2000
6．顾家裕等．库车前陆盆地演化与油气资源评价．塔里木石油勘探开发指挥部，北京石油勘探开发科学研究院，1999
7．周兴熙等．塔里木盆地天然气形成条件及分布规律．北京石油勘探开发科学研究院，1995
8.Smith D A. Theoretical consideration of sealing and non-sealing faults.AAPG.,1966,50:363～374
9.Engelder J T.Cataclasis and the generation of fault gouge. Geological society of American Bulletin,1974,85:1515～1522
10.Weber K J et al.The role of faults in hydrocarbon migration and trapping in Nigerian growth fault structures. Tenth Annual offshore Technology conference proceedings.1978,4:2643～2653
11.Harding T P and Tuminas A C.Structural interpretation of hydrocarbon traps sealed by basement normal blocks and at stable flank of foredeep basins and at rift basins.AAPG.,1989,73:812～840
12.Allan U S.Model for hydrocarbon migtation and entrapment within faulted.AAPG Bulletin.1989,73:803～811
13.Bouvier J D.Three-dimensional seismic interpretation and fault sealing investigation,Nun River Field,Nigeria.AAPG.,1989,11:1397～1411
14.Harding T P and Tnminas A C.Structural interpretation of hydrocarbon traps sealed by basement normal blocks and at stable flank of foredeep basins and at rift basins.AAPG.,1989,73:812～840
15.Knipe R J.Faulting process and fault seal.NPF special publication,1992,(1):325～342
16.Knott S D.Fault seal analysis in the North sea.AAPG.,1993,77:778～792
17.Jev B I et al.Akaso field,Nigeria:use of intergrated 3-D seismic,fault slicing,clay smearing,and RFT pressure data on fault trapping and dynamic leakage.AAPG.,1993,77:1389～1404
18.Gibson R G.Fault zone seals in siliclastic strata of the Columbus Basin,offshore Trinidad.AAPG.,1994,78
19.Robert D and Hatcher Jr.Structural geology,principles,concepts,and problems,second edition.New Jersy:Prentice-Hall Inc,1995
20.Knipe R J.Juxtaposition and seal diagrams to help analyze fault seals in hydrocabon reservoirs.AAPG.,1997,81(2): 187～195
21.Yielding G,Freeman B and Needham D T.Quantitive fault seal predication.AAPG.,1997,81(6):917～987
22．曹瑞成，陈章明．早期探区封闭性评价方法．石油学报，1992，13：33～37
23．孙宝珊，周新桂，邵兆刚．油田断裂封闭与通道作用研究．地质力学学报，1995，2(2)：1～7
24．吕延防．断层封闭性的定量研究方法．石油学报，1996，17：39～43
25．鲁兵，陈章明等．断面活动特征及其对油气的封闭作用．石油学报，1996，17：33～37
26．周新桂．利用排驱压力研究断裂封闭性及其在塔里木盆地北部地区的应用．地质力学学报，1997，3(2)：47～53
27．王志欣，信荃麟．关于地下断层封闭性讨论(以东营凹陷为例)．高校地质学报，1997，3(3)：294～300
28．白新华．浅析断裂活动对火山油气藏形成的控制作用．特种油气藏，1999，6(1)：6～9
29．付广，李风君，白明轩．断层侧向封闭性与垂向封闭性关系分析．大庆石油地质与开发，1998，17(2)：6～9
30．李亚辉，刘泽容，陈利．断裂封闭演化史研究方法及其应用．石油大学学报，1998，22(3)：15～18
31．童亨茂，李德同．应力对流体及其油气二次运移作用的几种模式．石油大学学报，1998，23(2)：14～17
32．邹华耀，金燕．断层封闭与油气运移和聚集．江汉石油学院学报，1999，2(1)：9～12
33．谯汉生，牛嘉玉，王明明．中国东部深部层系反向断层遮挡聚油原理与勘探实践．1999，26(6)：10～13
34．鲁兵，孔宪政等．断块结构与断块封闭性间的关系．石油勘探与开发，1999，26(6)：14～17
35．阎福礼，贾东等．油气运移的断层封闭因素探讨．江苏地质，2000，24(2)：95～100
36．付广，杨勉．利用地震资料判断断层封闭性的方法探讨．石油物探，2000，39(1)：70-76