泌阳凹陷下二门地区核桃园组油气成藏再认识

泌阳凹陷下二门地区位于泌阳凹陷东部,区内已发现下二门油田。该油田在核三上段至核二段下部为纯油藏,核二段上部为具气顶的油藏,核一段和廖庄组为纯气藏。经过40多年勘探开发,在下二门地区油气藏的发现难度越来越大,油气勘探陷入瓶颈期。为了进一步扩大该区勘探规模,取得新的油气发现,需要对该地区油气成藏机制再认识进而决定其下一步勘探方向。利用最新勘探和油藏资料,通过烃源条件分析、油源对比、天然气成分分析及油藏精细解剖,重新认识了该地区油气成藏机制。研究结果表明:泌阳凹陷深凹区的核二段泥页岩发育广,生烃指标较好,已进入低成熟阶段,具备较好的生油条件;下二门地区各层系油气与深凹区的源岩关系明确,表明油气以顺层运移为主,即核二段低熟油应该来自深凹区核二段低熟烃源岩,核三上段和核三下段原油分别来自深凹区核三上段和核三下段的成熟烃源岩;下二门地区核二段产出的天然气为低成熟伴生气,明显不同于深层凝析气,并非深层油气沿断层调整而来;下二门地区深层油气资源量大,但目前已发现储量规模有限,这预示着该区仍有较大的勘探潜力。因此,总结下二门地区的油气成藏特点及成藏模式,不仅可为该区油气勘探提供指导,而且可为我国东部类似断陷湖盆含油构造的进一步勘探提供借鉴。      

A study on accumulation and distribution of gas in southern Songliao Basin

A number of isolated fault sags in Late Jurassic--Early Cretaceous were developed in the early stage of southern Songliao Basin,and unified to a depression basin in the late stage.Therefore,multiple isolated lower petroliferous systems were formed with fault sags as source rocks.The source rocks of fault sags in Late Jurassic--Early Cretaceous were mainly described with gas generation as favorable source rocks,leading to the southern Songliao Basin rich in natural gas resources combined with organic gas resources in Nenjiang Formation.A number of tectonic movements in southern Songliao Basin led to the formation of abundant structural traps and complex fault systems,and controlled the distribution strata and positions of sources rocks in Late Jurassic--Early Cretaceous fault sags.The oil-gas reservoirs can be divided into two types,i.e.,primary and secondary ones.The primary oil-gas reservoirs were distributed in the fault sag strata and the bottom of overlying depression strata(lower Quan-1 Member).The oil-gas reservoir accumulation depended on the trap development situation and the distance from source rocks.The preservation conditions of oil-gas reservoirs depended on the degree of reconstruction in the late tectonism.The secondary oil-gas reservoirs were distribution in the Quantou Formation of depression strata,where oil and gas reservoir accumulation depended on three conditions,i.e.,trap development situation,deep gas sources and the fault to connect the shallow traps and deep gas sources.The southern Songliao Basin is rich in lower coal type gas,upper oil-gas and biogas resources,which are important resources in the future.     

缅甸安达曼海弧后坳陷天然气成藏要素及成藏模式

缅甸安达曼海已成为中国石油企业的重要海外探区之一。受印度板块向欧亚板块和西缅甸微地块多期斜向俯冲的影响,该区先后经历了被动陆缘、过渡型陆缘及主动陆缘的演化阶段,盆地属性与油气成藏特征极为复杂。通过系统梳理安达曼海弧后坳陷的烃源岩、储盖层、圈闭、输导体系与油气生-运-聚匹配史等成藏要素,总结出该区油气成藏主控因素。结果表明:本区发育渐新统—下中新统、中中新统与上新统3套泥质烃源岩,前二者为成熟烃源岩,后者为生物气源岩;岛弧带上碳酸盐岩礁体与斜坡带上砂体的储集条件良好;斜坡带继承性古隆起之上的断背斜圈闭容积大;高角度张性断裂与连通性砂体分别构成以垂向、侧向为主的输导体系。结合油气成因、运移方式与圈闭类型的主要特征,建立了2种成藏模式:①中央凹陷带浅层生物气或混源气垂向运移断块圈闭成藏模式;②东部斜坡带、西部斜坡和岛弧带热解气侧向运移断背斜-岩性圈闭成藏模式。西部斜坡及岛弧带上的碳酸盐岩礁体和东部斜坡带继承性古隆起之上的大型断背斜是有利勘探目标。     

西湖凹陷中央反转带中北部天然气高效成藏主控因素及富集规律

西湖凹陷中央反转带中北部大型气田成藏因素及动态匹配关系至今不明。通过针对烃源岩、储层、输导体系及成藏期等成藏关键因素进行系统分析,建立"源-储-圈-输"的动态成藏过程分析中央反转带中北部大气田的成藏主控因素。研究表明始新统宝石组与平湖组煤系烃源岩不仅生气强度大,而且中新世晚期以来的快速生、排气为中央反转带中北部的大中型天然气藏提供了充足油气源;花港组小于4 000 m地层的酸性地层水是形成有利储层的关键;中新世晚期发生的龙井运动强烈挤压作用使中央反转带发生了构造变形和断层开启活动,为圈闭和油气输导通道的形成创造了条件。综合"源-储-圈-输"分析认为成藏主控因素在生烃期的有机耦合造就了始新统煤系烃源岩高效生气及天然气的有效运移聚集成藏的全过程。本次研究为研究区大气田的勘探提供了借鉴。      

川东南丁山地区石牛栏组成脉流体来源与油气成藏

四川盆地东南部志留系油气成藏过程研究缺少成藏和破坏阶段的直接证据,丁山地区志留系石牛栏组储层内沥青和方解石脉体记录了储层内流体演化的信息,对研究油气藏油气成藏演化过程有重要的指示作用。运用显微岩相学、阴极发光、微区原位元素和流体包裹体分析方法,确定了古流体来源和活动时间,并恢复了甲烷包裹体古压力,结合烃源岩生烃演化史和地质特征揭示了石牛栏组油气成藏演化过程和主控因素。研究结果表明丁山地区石牛栏组储层内发育两期方解石脉体,原油充注发生在两期方解石脉形成之前。第一期方解石脉形成于距今约127 Ma,阴极发光颜色为褐红色,方解石脉形成于偏还原环境,成脉流体来源于同层位成岩流体。第二期方解石脉形成于距今约83 Ma,阴极发光颜色为褐黄色,方解石脉形成于偏氧化环境。龙马溪组烃源岩大量生油阶段在距今190~150 Ma之间,生成的石油充注到石牛栏组储层中并在距今约135 Ma裂解成气藏。甲烷包裹体捕获压力为51.77~57.46 MPa,储层压力系数为1.26~1.40。石牛栏组古气藏在燕山期以来,由于构造运动导致地层抬升剥蚀和断裂发育,促使天然气泄漏。      

长岭断陷龙凤山地区断裂与火石岭组火山岩油气运聚关系

龙凤山地区是长岭断陷重要的油气富集区,已发现油气多分布于断裂带附近,探讨断裂与油气运聚的关系具有重要意义。结合地震、测井、岩心、镜下薄片、流体包裹体观察及测温等资料,在断裂静态特征与断裂带结构识别研究基础上,综合分析断面形态、断裂活动特征与油气运聚的关系。研究结果表明,断裂的诱导裂缝带发育大量裂缝,有效地改善火山岩的物性,断裂可作为输导油气的优势运移通道;Ⅰ级断层的"汇聚型"断面形态控制油气主要富集位置;断层活动性与第一期成藏期匹配良好,断裂可作为输导油气的优势通道,后期断裂带裂缝被石英、方解石所充填,断裂对火山岩油气藏主要起封闭作用。      

断裂在贝尔凹陷油运聚成藏中作用

为研究断裂在贝尔凹陷油运聚成藏中的作用,通过油藏解剖分析油藏与断裂之间空间匹配关系.结果表明:贝尔凹陷油藏从基岩至大磨拐河组皆有分布,主要为断层油藏和受断层控制的基岩潜山油藏,平面上主要分布在与断裂活动有关的凹间隆、洼中隆、斜坡断阶带上.贝尔凹陷主要发育早期伸展、中期走滑和晚期反转(或长期发育)3种类型断裂,断裂对贝尔凹陷油运聚成藏主要起3方面控制作用:(1)长期发育断裂为南一段源岩生成油向大磨拐河组运移提供输导通道,早期伸展断裂错断使源储侧接,南一段源岩生成的油向基岩、铜钵庙组和南屯组储层侧向运移;(2)早期伸展断裂为基岩、铜钵庙组和南屯组油聚集提供遮挡条件;(3)断裂活动为不同层位油聚集提供构造背景.在贝尔凹陷断裂控藏有早期伸展断裂遮挡油聚集成藏和长期发育断裂输导油聚集成藏2种模式.     

渤海海域东部不同富油凹陷烃源岩生烃特征差异及意义

渤海海域东部发育多个富油凹陷,具有较大的生烃潜力,由于各凹陷形成和发育过程不同,导致不同凹陷、不同层段烃源岩热演化和生、排烃特征具有明显差异。通过对渤海海域东部3个富油凹陷多套烃源岩进行埋藏史、热史和生、排烃史研究,厘定了渤中凹陷、渤东凹陷和庙西凹陷烃源岩生、排烃时间以及演化特征。结果表明:①渤海海域东部地区不同构造单元烃源岩热演化程度具有"西高东低"的趋势,渤中凹陷最早生烃时间为31.5 Ma,渤东凹陷和庙西凹陷最早生烃时间分别为28.2,11.2 Ma,渤中凹陷最早排烃时间为27.8 Ma,而渤东凹陷和庙西凹陷最早排烃时间分别为20.9,6.7 Ma;②渤中凹陷烃源岩热演化程度较高,现今主要为储层提供天然气,为环渤中凹陷地区形成天然气藏和凝析气藏提供了气源;渤东凹陷、庙西凹陷热演化程度依次降低,为储层提供大量油源,盆地边缘地区主要以油藏为主。      

New insights into marine hydrocarbon geological conditions in the South Yellow Sea Basin: evidence from borehole CSDP-2

The South Yellow Sea Basin(SYSB) has multiple sets of proven source rocks and good hydrocarbon prospects,but no industrial oil and gas has been explored at present.To solve this puzzle for petroleum geologists,we systematically investigated the marine hydrocarbon geological conditions based on cores and testing data from borehole CSDP-2,the first exploration well with continuous coring in SYSB.The qualities of source rocks are evaluated in detail according to organic matter abundance,type,and maturity.The reservoir characterization mainly includes porosity,permeability,and reservoir space.Displacement pressure test and stratum thickness are the main foundations for defining the caprocks.Then,the oil-source rock correlation in the Permian and stratum model are analyzed to determine the favorable source-reservoir-caprock assemblages.The results show that three sets of effective source rocks(the Lower Triassic,Upper Permian,and Lower Permian),two sets of tight sandstone re servoirs(the Upper Permian and Lower Silurian-Upper Devonian),and two sets of caprocks(the Lower Triassic and Carboniferous) combine to constitute the hydrocarbon reservoir-forming as se mblages of "lower-ge neration and upper-accumlation" and "self-generation and self-accumlation",thus laying a solid foundation for promising petroleum prospects.The three sets of marine source rocks are characterized by successive generation and expulsion stages,which guarantees multistage hydrocarbon accumulation.Another three sets of continental source rocks distributed across the Middle Jurassic,Upper Cretaceous,and Paleogene depression areas,especially in the Northern Depression,may supplement some hydrocarbons for the Central Uplift through faults and the Indosinian unconformity.The favorable Permian exploration strata have been identified in the Central Uplift of SYSB.First,the Lower Permian and Upper Permian source rocks with high organic matter abundance and high thermal maturity supply sufficient hydrocarbons.Secondly,the interbedding relationship between the source rocks and sandstones in the Upper Permian strata ensures that hydrocarbons have been migrated into the nearby Upper Permian sandstones,reflecting near-source hydrocarbon accumulation.Finally,the good sealing property of the Lower Triassic Qinglong Formation caprocks plays an indispensable role in hydrocarbon preservation of the Permian reservoirs.This conclusion is supported by direct oil shows,gas logging anomalous layers,and hydrocarbon-bearing fluid inclusions.     

川西坳陷须三段致密砂岩气藏源储特征及成藏模式

川西坳陷须家河组致密气藏已成为拓展油气勘探、发现新储量的重要领域,致密气藏发育特征及其成藏机理成为目前亟需解决的关键科学问题之一。运用地球化学、地球物理和沉积学等分析方法,对须三段源储特征及成藏模式进行了系统分析,对高效烃源岩和优质储层进行了判别和预测,厘定了致密气藏成藏期次和成藏模式。得出以下结论:①须三段发育成熟-高成熟湖相烃源岩,以Ⅲ型干酪根为主,局部偶见Ⅱ₂型干酪根。发育于须三下亚段最大湖泛面附近,泥页岩体积分数在65%以上或者单层厚度较大、且1.50% ≤ w（TOC）≤ 10%时,属于高效烃源岩。②基于砂岩粒度中值识别出4期（S1,S2,S3和S4）优质储层,都属于低孔低渗-特低孔特低渗致密储层,中砂-细砂,粒度分布范围为0.5~0.062 5 mm,厚度一般5~10 m。主要发育于三角洲前缘和前三角洲。③烃源岩生排烃时间持续较长,中侏罗世开始生烃,一直持续至晚白垩世;从晚侏罗世开始排烃,早白垩世达到高峰。优质储层经历早期天然气持续充注和晚期凝析气充注,天然气充注时间要早于凝析气充注时间。形成了"断层垂向输导,先聚集后致密,晚期改造调整"的致密气藏成藏模式。      

Structural characteristics and hydrocarbon accumulation in Bashituo area,Tarim Basin

According to well logs, core, seismic and other geological data, the authors studied the tectonic evolution stages, trap formation stages, fault and fracture development in the Bashituo area, and furthermore, analyzed the time of hydrocarbon accumulation, hydrocarbon migration pathways and related controversial issues in the study area. It is believed that the tectonic evolution in the study area can be divided into three stages, namely Late Hercynian, the Early Himalayan and the Late Himalayan. In the Late Hercynian, tectonic movement led to folding and faulting, resulting in the embryonic form of anticlinal traps. In the Early Himalayan, affected by both tectonic movement and transformation, deep faults reactivated and cut through the Lower Tertiary strata. After the Early Himalayan tectonic movement, faulting stopped and no vertical migration pathway was available. Then hydrocarbon migrated laterally along the sand bodies in the Bachu Formation and accumulated in the Carboniferous reservoirs. However, the Carboniferous accumulation was formed late, and the tectonic movement was weak at the Late Himalayan, and faults were underdeveloped, so the reservoirs in the deep Bachu Formation were not disturbed.     

东海盆地西湖凹陷古近系花港组砂岩储层致密化与油气充注关系

东海盆地西湖凹陷致密砂岩气资源丰富,近年来古近系花港组成为勘探热点层位,但储层的致密化及与油气充注关系不明制约着花港组致密砂岩气的有效勘探和经济开发。在花港组储层特征的基础上,划分及厘定储层成岩作用类型与演化序列,恢复并揭示储层致密化过程及与油气充注的匹配关系。研究表明,西湖凹陷花港组储层砂岩主要经历压实、胶结和溶蚀3种成岩作用,压实作用是导致花港组储层孔隙损失和致密化的根本原因;并经历同生阶段、早成岩阶段（A、B期）和中成岩阶段（A、B期）共3阶段5期次的成岩演化过程;在中成岩阶段A₂期时成岩环境开始由酸性向碱性发生转变,并伴随着晚期碳酸盐、硅质等胶结作用发育以及机械压实作用持续增强,储层逐渐趋于致密化;结合与油气主成藏期（7~0 Ma）的耦合关系将研究区花港组储层划分为3种类型:成藏未致密型储层、成藏同步致密型储层、成藏已致密型储层。研究梳理了西湖凹陷花港组储层特征、成岩演化序列、储层致密化及与油气充注的耦合关系,为下一步研究区致密砂岩气的勘探提供理论支持。      

Accumulation model and prediction of Miocene heavy oil distribution in Gulf of Suez Basin,Egypt

The Gulf of Suez Basin is a very mature and extremely prospective petroleum province.Many heavy oil fields have been found in the Basin, and such reserves are abundant.Characteristics and models of heavy oil are analyzed in this study based on tectonic, basin evolution, stratigraphic distribution and geochemical data. The best reservoirs of heavy oil are Miocene sandstone and limestone formations.Source rocks of hydrocarbon include deep limestone and shale of the Brown Limestone, the Thebes Formation and the Rudeis Formation. Thick evaporite rocks with rock salts and anhydrites deposited broadly throughout the basin are the most impor-tant regional seals, whereas Miocene shales are intraformational and regional seals that cover small areas.Heavy oil could be directly generated or densified during vertical migration along faults and reservoir accumulation. The heavy oil accumulation model is a mixed model that includes three mechanisms:fault dispersal, sulfocom-pound reactions and hydrocarbons generated from immature source rock.After analyzing the model and the dis-tribution of source rocks, reservoirs, heavy oil fields and structures, it is concluded that the potential heavy oil area is at the center of the basin.     

鄂尔多斯盆地地层埋藏演化与油气成藏分析

地层埋藏状况对有机质生烃及油藏保存具有重要的控制作用.通过对鄂尔多斯盆地晚三叠世以来地层埋藏史和有机质热演化生烃史的恢复,对比盆地不同地区之间地层剥蚀和埋藏特点,探讨地层埋藏演化特征对油气成藏的影响,分析地层埋藏对有机质生烃及油藏保存条件的影响.结果表明:在鄂尔多斯盆地晚三叠世以来经历的4期(T3、J1、J2、K1)沉降—抬升循环演化过程中,不同地区的沉积埋藏深度和埋藏速率存在明显差异.一方面导致各地区间长7烃源岩进入生烃的时间提前或滞后.北部古峰庄地区和中部白豹地区在J2期已进入早期生烃,姬塬和镇北地区在J3期进入早期生烃,而南部西峰、洛川地区和东部陕北地区早期生烃的时间是K1早中期.进入大量生烃阶段的时间基本都在K1期.另一方面导致地区间成藏封存条件的变化.在北部和中南部地区,地层埋藏深度大,沉积速率高,形成很好的封闭条件.各生烃阶段,特别是早期生成油气也可很好地保存而成藏.     

火山岩岩性、储层的岩石物理弹性参数判别:以松辽盆地北部徐家围子断陷营城组为例

徐家围子断陷火山岩岩性种类多,岩性复杂,不同岩性岩石特征差异大,火山岩岩性、储层的地震预测难度大,亟待通过岩石物理的分析,有效指导火山岩储层地震预测。通过对13种弹性参数敏感性交会分析,首次利用密度和剪切模量将徐家围子断陷营城组复杂火山岩岩性划分为玄武岩类、安山岩类和流纹岩类3类,且同一岩类岩性都具有相同的储层参数特征,在区分岩性基础上,利用密度和纵波速度双参数可对3类岩性组的储层进行直接识别,为火山岩储层叠前反演预测技术提供理论基础。      

巴西桑托斯盆地C区块火成岩发育特征及对油气成藏的影响

桑托斯盆地盐下碳酸盐储层中火成岩分布广泛,以盆地C区块为解剖区,通过对区内火成岩岩石学、年代学以及CO₂气体同位素测试分析等,明确了区内火成岩发育特征,剖析了其对油气成藏的影响。C区块至少经历了阿普特期和圣通-坎潘期2期岩浆活动,其中阿普特期岩浆以喷发岩为主,经历了多次喷发,并伴有多次侵入;圣通-坎潘期岩浆规模较小,侵入比较随机。阿普特期岩浆多次喷发改造古地形,形成局部凸起,促成并控制了Itapema组介壳灰岩的沉积发育,形成了巨厚的火山岩-介壳灰岩复合体,不仅造成了局部构造反转和圈闭高点迁移,而且也促成了Barra Velha组优质微生物灰岩的发育。区块北翼属早期古隆,Barra Velha组也发育一定规模微生物灰岩滩体。圣通-坎潘期及之后岩浆活动伴生的CO₂大规模侵入,对烃类流体进行萃取和抽提改造,形成含凝析油的CO₂气藏。      

东海盆地西湖凹陷武云亭构造油气来源与成藏模式

近年来，东海盆地西湖凹陷平湖斜坡带武云亭构造油气勘探获得了较好的商业发现，但已钻探的A井与B井流体性质差异较大，A井为气井、B井为油井。通过生物标志化合物对比、碳同位素分析及流体包裹体分析，对武云亭构造油气来源、充注期次及成藏模式进行了分析，结果表明武云亭构造油为正常成熟原油，主要来源于本地宁波19洼平湖组煤系烃源岩；天然气有两种，一种为高成熟天然气，主要来源于东侧主洼宁波27洼平湖组烃源岩，另一种为正常成熟天然气，主要来源于本地次洼宁波19洼烃源岩。包裹体荧光呈现为淡黄色油气包裹体和无色气包裹体，均一温度表明武云亭构造主要经历两期油气充注，时间为2 Ma和现今。武云亭构造油气来源丰富，成藏过程复杂，基于油气来源及成藏特征划分为"双源侧向晚期次生型"和"单源垂向晚期原生型"两种成藏模式。      

黔东北梵净山地区沥青Re-Os同位素年龄对油气成藏年代的约束

黔东北梵净山地区位于雪峰隆起西缘,前寒武纪-早古生代黑色有机质岩系发育,沥青显示广泛。该区在新元古代-中生代经历了晋宁期、加里东期及印支期-燕山期多幕构造变形,前人对后两期构造与油气成藏的响应关系研究较多,而关于晋宁期构造与油气成藏之间的匹配关系则鲜有报道。选取黔东北梵净山地区宝塔组灰岩溶蚀孔、洞内的沥青开展了Re-Os同位素研究,测试结果显示等时线年龄为（915±129）Ma。结合区域地质分析表明,梵净山地区存在晋宁期原生油藏,在加里东期被改造形成次生油藏,古隆起控制了次生油气藏的分布。本研究丰富了雪峰隆起西缘油气成藏期次,同时也促进了复杂构造变形条件下次生油气藏成藏机理研究,对我国南方新元古界油气勘探有重要意义。      

成藏期后的断层活动对油气聚集与保存的控制作用

针对油气勘探中同一断层不同部位油气富集差异性,利用地震解释资料和钻探资料,研究辽河西部凹陷齐家—鸳鸯沟地区沙二段油气聚集与保存所需最低的断层后期活动强度.结果表明:沙二段内主要发育4条走向相同的断层,在主要油气成藏期—东营组沉积末期之后馆陶组—第四系的活动过程中,其中f1断层活动强度最大,对油气聚集的破坏作用最强;其次是f3断层,再次是f4断层,f2断层活动最弱,断层后期活动强度与油气分布之间具有密切关系,断层后期活动强度越小的断层或部位,油气越富集,油气钻探成功率越高;反之,则越低.沙二段油气聚集与保存所需最低的断层后期活动强度约为2m/Ma.     

川西坳陷深盆气研究进展与问题讨论

川西坳陷总体上看具有与加拿大阿尔伯达盆地类似的地质条件，极可能发育深盆气藏。详细研究表明，两盆地在构造回返程度、地层压力特征、气源岩生气时代等方面存在较大差异，不宜将川西坳陷的天然气聚集简单地归结为阿尔伯达型深盆气藏。研究其成因和分布规律，应从该盆地的实际资料入手，进行成藏机理研究，而不能简单地借用已有的模式进行对比。研究认为，川西坳陷的天然气藏具有“气水倒置”的特征；川西坳陷的断裂体系深刻地影响着深盆气聚集成藏，导致盆地天然气的独特分布形式。对深盆气成藏诸控制因素，包括源岩厚度、有机质成熟度、生气强度、储集层厚度与物性、断裂构造特征等的综合研究，对川西坳陷深盆气藏的分布进行了预测。