贝尔凹陷布达特群潜山油气成藏机理及主控因素研究

【作者】 李文学；

【导师】 吕延防；

【作者基本信息】 大庆石油大学 ， 油气田地质工程， 2006， 博士

【摘要】 在综合运用石油地质学、地球化学、地球物理等多种学科知识,利用钻井、地震、测井和各种分析测试资料,对贝尔断陷布达特群潜山油气成藏进行了研究。通过有机碳、氯仿沥青“A”、碳同位素含量和族组分含量等地球化学指标的分析,对布达特群潜山油岩进行了对比研究得到,布达特群潜山原油主要来自于南一段和南二段源岩,其次是兴安岭群源岩,再次为布达特群自身源岩;南屯组源岩品质相对较好,供烃条件最好,其次是兴安岭群源岩,布达特群源岩质量相对较差。通过探井岩心观察和镜下鉴定,得到布达特群潜山储层储集空间主要是裂缝,其次是岩石孔隙,裂缝发育主要受岩性、断层和古地貌等条件的控制,较好等级的储层主要位于呼和诺仁断鼻构造带贝5井北西方向、霍多莫尔背斜构造带与苏德尔特潜山构造带之间、贝40井以北小块区域、贝西洼槽贝301井以西地区,中等储层位于苏德尔特潜山构造带,部分位于霍多莫尔背斜构造带以北的霍3井与海参2井以北地区,较差储层则位于贝西洼槽与敖瑙海洼槽以南地区,霍多莫尔背斜构造带大部分地区。贝尔断陷布达特群潜山盖层好,封盖层零星分布,主要分布在敖瑙海洼槽中部的小面积区域、呼和诺仁断鼻构造带中西部地区、霍多莫尔背斜构造带中部的狭长地区、苏德尔特潜山与敖瑙海洼槽交接的西部局部区域、苏德尔特潜山构造带的西南部,面积分散且相对较小,中等封盖区主要分布在敖瑙海洼槽大部分地区、不勒洪布斯断隆及希勒敖包洼槽中部的大部分地区,以及苏德尔特潜山构造带地区,霍多莫尔背斜构造带南北两侧贝西洼槽的西部边部区域,差封盖区主要分布在贝尔断陷的周边地区。通过流体包裹体均一温度,结合埋藏史和热史分析可以得出,贝尔断陷布达特群潜山油气注入主要有两个时期,一次是在大磨拐河组沉积末期,另一次是在伊敏组沉积末期。贝尔断陷布达特群潜山油气输导通道主要有潜山顶面的不整合面以及潜山内部的断裂,主要有油气沿断裂和不整合面组合侧向运移古潜山顶面风化壳聚集成藏和油气沿断裂侧向运移古潜山内部裂缝破碎带聚集成藏2种模式。布达特群潜山油藏可分为潜山顶部基岩风化壳油藏和潜山内部裂缝破碎带油藏2种类型,南屯组源岩生烃洼槽及其附近区域、源岩断裂发育而破坏断裂不发育区域、裂缝发育区、油气汇聚区以及中期变形形成的断阶和断垒型潜山地区是贝尔凹陷布达特群潜山油气成藏与分布的主控因素。综合各种成藏与分布主控因素得到,贝尔凹陷布达特群潜山顶部基岩风化壳油藏形成与分布的有利地区主要分布凹陷中部,位于苏德尔特潜山带中部和贝西洼槽中部和北部偏东地区,潜山内部裂缝破碎带油气藏形成与分布的有利区主要分布在苏德尔特潜山中部、贝西洼槽中南部地区和北部地区。苏德尔特潜山北部、敖脑海洼槽中部和苏乃诺尔构造带东部局部地区。更多还原

【Abstract】 Based on amount of datum of oil geology , geochemistry and geophysics , this paper researches on accumulation of oil deposit of Budate group in Beier depression combining with analysis and reseaching .Through analyzing geochemical indexes , including organic carbon , chloroform extract”A”, and carbon isotope etcal. .It can be concluded that the main sources of oil and the quality of sourcerocks is Nantun group , its’conditions of providing oil is best , the next is Xinganling group , the least is Budate group . Through analyzing of cores and judging undering microscope, it found that the main reservoirs spaces are fissures , the second is rock hole . the developing regulation of fissures and holes can be found , their width and indensity have some relations with macrofractures , and fissures are effected by lithology , fractures , palaeo-geomorphology and other factors . The best region for reservoir locates at northwest of Bei 5 Huhenuoren structural belt , region between Huoduomoer and Sudeerte structural belt ,the north small region of Bei 40 well and the west region of Bei301 . The middle region locates ai Sudeerte buried hill structural belt , party are at Huoduomoer anticline structural belt Huo 3 well and the north of Haican 2 well . The least are at the south region of Beixi billabong and Aonaohai billabong , the most part of Huoduomoer anticline structural belt . It got the best caprock locates at the scatter region , such as little region of middle Huhunuoren and Aonaohai billabong , long and narrow region of Huoduomoer anticline structural belt , Sudeerte fracture belt’s southwest and middle region . The west of Aonaohai and the mai parts of Bulehongbusi and Xileaobao are the middle level , the bad region locates at east of Beier depression north of Huhubuoren and the west region and Mudstone of Xinganling group are at the group except those parts . Through analyzing homogeneous tempreture about fluid inclusion enclave , with heat history and embedding history , this paper claim that there are two main period which oil accumulate to buried hill , one is the end of Yimin group , another is end of Damoguaihe group . It conclude the main pathways are fractures in top of burried hill and fractures. According to that , there are two main model of accumulating reservoirs , one is oil accumulating to the unconformity surface on th top of buride hill through fractures and combination of unconformity ,the other is accumulating through fissures and crushed zone inside laterally Combining with all factors , there are two models can be structured , that is side migrating to weathering crust of buried hill , vertical migrating to inside fractures and migrating through surfaces created by fractures . Above all , it can be found that , analyzing comprehensively , oil reservoirs in top of weathering crust and inside fractures are two main types and region near or the mid of sourcerock , and region of sourcerock or nearby , affluently developed fractures which didn’t destroy caprocks , area witch are full of fissures , accumulating ereas and buried hill of fault block and sag formed in the middle stage are main controlling factors to form oil reservoirs . Considering all factors , this paper got the main region for next exploring , with geological dynamic and static datum , oil reservoirs in weathering crust of buried hills mainly locates at center of Sudeerte structurcal belt and the north and middle region of Beixi billabong; those formed in fissures and crushed zone locates at south parts and the north of Beixi region , the mid and the north of Sudeerte structurcal belt , the center of Aonaohai billabong and the east of Surennuoer structurcal belt更多还原