Characteristics and evolution of strike-slip tectonics of the Liaohe Western Sag,Bohai Bay Basin

Because of its rich oil and gas resources and the special tectonic location of the Liaohe Western Sag （the Tanlu Fault traverses the sag）, Bohai Bay Basin, a detailed study of its strike-slip tectonics is significant in revealing the sag＇s tectonic evolution, its control on hydrocarbon accumulation, and the activity history of the northern section of the Tanlu Fault in the Cenozoic. Through systematic structure analysis of 3D seismic data of the Liaohe Western Sag, combined with balanced section analysis, a variety of structural features in relation to right-lateral strike-slip faults, such as echelon normal faults, ＂comb＂ structure, ＂flower＂ structure,＂interpretable＂ and ＂buried＂ strike-slip faults have been revealed exist in the Liaohe Western Sag. According to the research in this paper, the complex structural phenomena in the Liaohe Western Sag could be reasonably interpreted as right-lateral strike-slip activity and the strike-slip activities of the Liaohe Western Sag began in the early Oligocene. The activity was weak at the beginning （E3s1-2）, then strengthened gradually and reached its strongest level in the late Oligocene （E3d1）. In the Miocene, the strike-slip activity was low and then strengthened significantly once again from the Pliocene to the present. It is speculated that the entire northern section of the Tanlu Fault has had a similar evolution history since the Oligocene.

Tectonic evolution and its control over deposition in fault basins: A case study of the Western Sag of the Cenozoic Liaohe Depression, eastern China

The main petroliferous basins in eastern China are Cenozoic fault basins, most of which have experienced two-stage tectonic evolution, i.e., rifting subsidence in the Paleogene and post-rifting thermal subsidence in the Neogene-Quaternary. The episodic tectonic evolution and syndepositional faulting had significant influence on the fault basins in terms of accommodation space, deposition rate, and depositional facies zones. In this study, the tectonic deformation characteristics and the tectonic-depositional evolution of the Western Sag of the Cenozoic Liaohe Depression were investigated by comprehensive analysis of the available geological and geophysical data using the modern theory of tectonic geology and the balanced section technique. The tectonic deformation of the Cenozoic fault basin was characterized by superimposed faults and depression. In addition, there existed relatively independent but still related extensional tectonic systems and strike-slip tectonic systems. The tectonic evolution of the fault basin involved five stages, i.e., initial rifting stage （E2s4）, intense faulting stage （E2s3）, fault-depression transition stage （E3sl2）, differential uplifting stage （E3d）, and depression stage （N-Q）. According to the characteristics of tectonic development and evolution of the Western Sag, the depositional evolution in the Cenozoic fault basin was divided into two stages, i.e., multi-episodic rifting filling in the Paleogene and post-rifting filling in the Neogene-Quaternary. The former rifting stage was further subdivided into four episodes with different characteristics of depositional development. The episodic faulting controlled the filling process and filling pattern of the Cenozoic Western Sag as well as the development and spatial distribution of associated depositional systems, whereas the syndepositional faults that developed in multiple stages in various tectonic positions controlled the development of depositional systems and sand bodies in the Western Sag. That is, the fault terraces on steep slopes controlled the development of sand bodies, the fault terraces on gentle slopes controlled the development of low-stand fan bodies, and the fault terraces or fault troughs in the central basin controlled the development of fluxoturbidite bodies.

Estimation on organic carbon content of source rocks by logging evaluation method as exemplified by those of the 4^(th) and 3^(rd) members of the Shahejie Formation in western sag of the Liaohe Oilfield

One of the most important tasks of evaluating natural resources of petroliferous basins is to determine the organic matter abundance of source rocks in the basin.The usual method for assessing the organic carbon content of source rocks is based on laboratory analyses.There is a deviation in calculating organic carbon content due to the heterogeneous distribution of organic matter and the artificial factors when sampling.According to the continuous characteristics of information logging,the conventional logging curves(mainly acoustics and resistivity,etc.) were calibrated with the organic carbon experimental data of cores,cuttings or sidewall cores.The organic carbon content of source rocks of the 4 th(Es 4) and 3 rd(Es 3) members of the Shahejie Formation in western sag in the Liaohe depression was estimated directly by a great amount of continuous data including resistivity and acoustic logging,etc.Comparison between the results from computer processing and lab analysis of logging data shows that the organic carbon contents derived from the computer processing of logging data have the same reliability and accuracy as the lab analysis results.The present data show that this method is suitable to evaluate the source rocks of western sag in the Liaohe depression and has great potential in evaluating natural resources of sedimentary basins in the future.On the basis of logging data of source rocks,experimental data and existing geochemical analyses of the Liaohe Oilfield,the corresponding total organic carbon(TOC) isograms of source rocks were plotted.The source rocks of Es 4 and Es 3 of the Shahejie Formation are thought to be beneficial to hydrocarbon accumulation due to the high TOC.

Conditions for the Formation of Oil and Gas Pools in Tertiary Volcanics in the Western Part of the Huimin Sag, Shandong and Their Distribution

Conditions for the Formation of oil and gas pools in Tertiary volcanics in the western part of the Huimin sag, Shandong and then (?)stribution have been studied based on the geological, seismic and well-logging information. In this paper, the types and lithofacies of the volcanic rocks in the western part of the Huimin sag are described; the relationship between rocks and electrical properties, the seismic reflection structures, the development and distribution of the volcanic rocks are expounded; and the fourfold role of the volcanic activities in the formation of the oil and gas pools is also dealt with. It is considered by the authors that the volcanic activities were not destructive to the formation of oil and gas pools but a factor favourable to the accumulation of organic matters and their conversion to hydrocarbon. The volcanic rocks might have served as reservoir rocks and cap rocks, or as a synsedimentary anticline. The prerequisites and important factors for the formation of oil and gas pools and their distribution are pointed out in the paper.

准噶尔盆地盆1井西凹陷石炭系火山岩凝析气藏的发现与勘探启示

准噶尔盆地石炭系火山岩油气藏是油气勘探的重点领域之一。根据录测井资料、地球化学分析数据及岩石薄片鉴定资料,结合地球物理方法,厘清了准噶尔盆地盆1井西凹陷石炭系火山岩油气成藏的主控因素,总结出深层火山岩气藏富集规律,明确了有利勘探方向。研究结果表明:(1)准噶尔盆地盆1井西凹陷风城组烃源岩厚度为100~300 m,面积约为5 400 km2,整体进入生凝析油—干气阶段,生气强度大于20×108m3/km2,为凹陷提供了丰富的天然气源。(2)研究区石炭系火山岩岩性复杂,爆发作用形成的安山质火山角砾岩受到风化淋滤作用,可形成物性较好的风化壳型储层。石炭系—二叠系大型不整合面和广泛发育的深大断裂是重要的输导体系,二叠系上乌尔禾组泥岩作为区域盖层,为凝析气成藏提供了保存条件,油藏主要分布在高部位,气藏分布于低部位。(3)通过“两宽一高”(宽方位、宽频带、高密度)技术,提高地震成像精度,联合时-频电磁技术(TFEM),实现了石炭系火山岩的精细刻画,为深层油气藏的勘探提供了有力支撑。石西16井的重大突破,证实了盆1井西凹陷石炭系火山岩具有巨大的勘探潜力。

辽河盆地西部凹陷中深层超压体系成因机制研究

辽河盆地西部凹陷中深层发育明显超压,明确其超压的分布和形成机制对该地区中深层油气勘探具有重要意义。基于实测地层压力、测井曲线组合、超压成因判识图版及盆地模拟等方法,针对西部凹陷中深层超压发育特征、成因机制及超压对成藏的控制作用进行了研究。结果表明,西部凹陷整体发育超压型、常压型、低压型3类温压系统,超压主要发育在2500~4000 m的中深层,超压成因以欠压实作用为主。在中段冷家—雷家地区沙三段地层超压除欠压实作用贡献外,局部伴有生烃增压、成岩作用和构造挤压的混合贡献,北段因遭受过强烈的抬升剥蚀作用,表现为异常低压为主。采用盆地模拟手段对超压成因贡献量进行评价,其压力演化存在3期:第1期以构造沉降作用导致的欠压实作用为主;第2期由于地层抬升泄压,欠压实和流体膨胀作用经历短暂停止;第3期烃源岩到达生烃高峰,生烃增压作用逐渐增强且流体膨胀增压可达5 MPa。

塔里木盆地西北缘乌什西次凹的地层系统和构造特征

乌什西次凹位于塔里木盆地西北缘,隶属于库车坳陷的乌什凹陷。它位于南天山主山脉(哈尔克山)和塔里木盆地柯坪—温宿凸起之间。区域构造格局上,这里是塔里木克拉通向西北自然延伸的部分。次凹北缘的阿合奇断裂是南天山造山带和塔里木克拉通的分界。乌什西次凹内发育与柯坪—温宿凸起相似的晚前寒武纪—古生代地层系统,包括寒武系、奥陶系和石炭系的烃源岩。新近系—第四系碎屑岩建造直接不整合于变形的古生代被动大陆边缘碎屑岩—碳酸盐岩沉积建造之上;剖面上,向南天山方向加厚,向塔里木克拉通方向减薄,呈现典型的前陆盆地剖面结构特征。这是一个晚新生代陆内前陆盆地,叠加在晚海西期—燕山期古隆起之上。这里的构造变形主要有3期,分别是中海西期、晚海西期—印支期和晚喜山期。变形以厚皮冲断构造及其相关褶皱为主,薄皮构造不发育。平面上,主构造线走向NE-SW。剖面上,以南天山向塔里木冲断为主。

准噶尔盆地盆1井西凹陷及周缘深层二叠系超压形成机制及演化特征

为明确准噶尔盆地盆1井西凹陷及周缘深层二叠系超压形成机制及演化特征,基于钻井、测井、实测地层压力等资料,运用测井曲线组合分析法和交会图版法以及盆地模拟技术,对超压成因机制及演化特征进行分析,并定量表征目的层不同成因类型超压的贡献率。结果表明:①研究区深层二叠系不同岩性地层超压成因具有明显差异,其中风城组和下乌尔禾组烃源岩层超压成因主要为生烃和欠压实作用,其中生烃作用占主导;泥岩盖层超压成因主要为欠压实作用;而风城组和下乌尔禾组储层超压成因主要为超压传递和欠压实作用。②研究区风城组烃源岩生烃增压自早二叠世开始,现今达到最大,不同构造部位增压大小差别较小,烃源岩层超压主要分布于39.43~49.16MPa,但其贡献率具有明显差异,凸起区较大,而凹陷区较小;凸起区和凹陷区生烃增压对总超压贡献率分别为84.49%~94.41%和65%~67.3%,研究区下乌尔禾组烃源岩生烃增压大小与风城组具有相似的规律;欠压实作用对泥岩盖层超压的贡献率一般为100%。③研究区二叠系储层超压传递增压主要形成于晚侏罗世至早白垩世以及古近纪至今,其贡献率在不同凸起区存在明显差异,达巴松凸起和石西凸起分别为21.86%~23.35%和100%。厘清研究区深层、超深层超压的分布规律,可以为盆地新区的进一步开发提供依据。

准噶尔盆地盆1井西凹陷侏罗系三工河组凝析气藏特征及成因机制

基于油气地球化学、试油结果与凝析气相态分析实验等资料,采用盆地模拟技术分析了准噶尔盆地盆1井西凹陷前哨井区侏罗系三工河组凝析气藏特征,并对凝析气藏的成藏过程与成因机制进行了详细研究。研究结果表明:①盆1井西凹陷侏罗系三工河组凝析气藏为构造-岩性油气藏,优质储层岩性主要为灰色细—中粒长石岩屑砂岩,孔隙度为2.70%~16.10%,平均为12.10%,渗透率为0.016~109.000 mD,平均为14.170 mD,属于中孔、低渗储层,与下伏的二叠系风城组和下乌尔禾组2套烃源岩形成了良好的储-盖组合。②研究区凝析油表现为低密度、低黏度、低凝固点和低含蜡量等特征,正构烷烃以低—中碳数为主,为下乌尔禾组烃源岩成熟—高成熟阶段的产物。③研究区凝析气藏天然气组分以烃类气为主,甲烷与乙烷碳同位素值分布集中,分别为-37.40‰~-36.84‰与-27.55‰~-26.54‰,为腐殖型烃源岩裂解气,来源于下乌尔禾组烃源岩。④研究区下乌尔禾组烃源岩于古近纪早期生成的凝析油气经过不断调整最终于新近纪早期充注形成凝析气藏,从成藏至现今储层流体组分未发生改变,油气藏相态类型也未发生改变,为原生型凝析气藏。

西湖凹陷西次凹古近系花港组—平湖组深层油气成藏过程

西湖凹陷西次凹古近系花港组和平湖组深层油气资源丰富,是东海陆架盆地勘探开发新领域,受储层差异致密化影响,油气成藏机理复杂。为了厘清西次凹深层油气成藏过程,本文通过流体包裹体岩相学特征、显微测温、激光拉曼光谱、包裹体所含油气地球化学等实验分析,结合构造演化、地层埋藏史、热史等,开展了系统的储层特征、油气成藏期次、成藏过程研究。结果表明,花港组深层(>4000 m)和平湖组储层均已致密化,溶蚀孔隙是主要的储集孔隙类型;花港组和平湖组均发育两期油气包裹体,早期含油包裹体较多,晚期以天然气包裹体为主,成藏时间分别为龙井运动期和冲绳运动期,以晚期天然气成藏最为关键。包裹体中油气地球化学特征类似,反映生烃母质以高等植物生源为主,低等生物为辅,与平湖组煤系烃源岩特征一致。冲绳运动叠加平湖组生气增压是晚期天然气成藏的主要动力,此时H10段及以上储层未致密化。根据储层致密化与成藏时序匹配关系可将西次凹M构造深层油气藏类型划分为常规型、先成藏后致密型、先致密后成藏型和边成藏边致密型4种。本文成果可为研究区下一步致密砂岩气的勘探开发部署提供重要的理论依据。

珠江口盆地文昌A凹陷西部新生代断裂体系特征及演化过程

断裂体系发育是珠江口盆地文昌A凹陷西部地区新生代构造演化的重要表现形式。利用最新的三维地震资料,在精细刻画断裂体系静态特征的基础上,结合断层活动速率计算恢复断裂体系的动态演化过程,明确了文昌A凹陷西部地区新生代断裂体系发育的时空差异;并结合区域应力背景分析,探讨了断裂体系演化的成因机制,认为新生代以来三大板块间俯冲、碰撞及古南海俯冲消亡、新南海扩张共同造成的南海北缘区域伸展应力场顺时针旋转控制了断裂体系演化的时空差异。研究表明,文昌A凹陷西部地区断裂体系的发育演化经历了裂陷、拗陷与构造活化三个阶段,分别发育了NE(NEE)向、近EW向以及NW(NWW)向三组优势方向断裂,揭示了区域应力场伸展方向由NW—SE向到近SN向再到NNE—SSW向顺时针转变的过程;依据断裂的组合及沿承关系可将其划分为早期发育的NE向与后期发育的NW向两组交叠断裂带,NE向断裂带活动强度大、具有强烈伸展性质,NW向断裂带与基底先存断裂密切相关,活动强度弱、叠加一定走滑性质。文昌A凹陷西部新生代断裂体系演化的时空差异是对南海北缘区域应力场顺时针旋转的响应。

南海西部原油领域勘探进展与突破方向

南海西部原油领域历经多年勘探,探明程度高,勘探难度日益增大。近年来,转变思路,大力拓展新领域。攻关岩性圈闭发育机制,建立了流三段“低位转换带控砂,湖侵互层叠置连片”的广覆式砂体沉积模式,阐明了大面积连片岩性圈闭形成机理,创建了“近源广覆式有序富集”成藏模式,发现南海西部首个大中型岩性油田;攻关深层大型储集体和优质储层发育机制,建立构造-层序-地貌耦合控砂分析技术,提出了限制型辫状河三角洲发育模式,明确了相带与溶蚀差异控储机制,涠西南凹陷B洼深层、乌石凹陷反转构造带倾末端、文昌B凹陷双古领域获得了勘探突破。同时明确了大型构造脊大型储集体耦合的深层领域、富烃凹陷周缘地层-岩性圈闭领域、源储对接潜山领域和烃源条件落实边部凹陷是南海西部原油领域下步重点勘探方向。

柴达木盆地西部坳陷古近系全油气系统特征与油气成藏模式

基于柴达木盆地西部坳陷油气勘探实践,结合地震、钻井、测井及地球化学等资料,对柴西坳陷古近系全油气系统基本地质条件、油气分布特征、成藏运聚动力与成藏模式开展研究。研究表明:柴西坳陷发育全球独具特色的“巨厚山地式”全油气系统,围绕古近系下干柴沟组上段烃源岩层系,从盆缘向湖盆中心,平面上构造油气藏、岩性油气藏、页岩油与页岩气有序分布、纵向上叠置连片。柴西坳陷古近系全油气系统具有3方面独特性:(1)低有机质丰度烃源岩“低碳富氢”,单位有机碳生烃能力强;(2)咸化湖盆沉积巨厚,坳陷中心沉积以混源为主,岩相与储集空间纵横向变化快;(3)喜马拉雅期走滑挤压强改造,山地式全油气系统油气差异富集。柴西坳陷古近系全油气系统是源储盖与输导体系协调演化的结果,具有低碳富氢烃源岩全过程生烃、巨厚储集体全坳陷沉积、挤压走滑断裂体促进油气全方位调整、常规-非常规油气全系列分布的特征。受控于喜马拉雅期强构造运动影响,柴西坳陷经历了先拗后隆的演化过程,在湖盆中心发育广义页岩油,在超过2 000 m厚度的沉积体系中,油气连续分布于烃源岩层系内的薄层状灰云岩与紧邻生烃灶的藻灰岩中,白云石晶间孔、纹层缝与断溶体是有效储集空间。相关认识可进一步丰富和发展中国陆相湖盆全油气系统理论,并为柴达木盆地油气综合勘探提供理论指导与技术支持。

Further Recognition of Petroleum Exploration Potential of Marine Carbonates in Western Tarim Basin

A series of significant discoveries in marine carbonate rocks show great petroleum exploration potential in the Tarim Basin. However, the oil and gas fields discovered in the carbonate rocks are mainly distributed around the Manjiaer Sag in the eastern Tarim Basin. Some explorations occurred and no oil or gas field was discovered around the Awati Sag in the western Tarim Basin. Information from wells and outcrops reveals that there are excellent oil and gas source rock conditions around the Awati Sag. Transformed reef-shoal reservoirs could be formed in the Ordovician carbonate rocks with paleo-geographic background and hydrothermal conditions. Therefore, it is necessary to make a systematical study and overall evaluation of the potential of the periphery of the Awati Sag in terms of source rock evolution, resource potential, high-grade reservoir formation and distribution, and main factors controlling hydrocarbon migration and accumulation.

辽河断陷盆地地层划分对比标志研究

辽河断陷地质构造十分复杂,造成了古近系分割性强、厚度和岩性纵横向变化大等特点.寻找识别标志层,进行精细地层划分对比一直是本区地层研究的难点,制约了油气勘探开发部署.从盆地构造沉积演化分析入手,通过多重地层划分对比方法,对西部凹陷近千口探井进行系统研究,识别了古近系7个区域标志层,描述了古近系沙河街组共14种不同类型底界的接触关系和岩电特征,并以各种类型底界的代表井为基准,划分出同一地层单元内不同类型底界的分布区,使陆相断陷盆地地层划分对比更加简单、具体、易操作,为油气精细勘探提供基础支撑.

准噶尔盆地玛湖凹陷西斜坡原油油源解析:基于单体烃碳同位素组成、分子比值与浓度定量分析

通过对玛湖凹陷中部(西斜坡)24个原油样品饱和烃组分、芳烃组分、二苯并噻吩(DBT)、甲基二苯并噻吩(MDBTs)、二苯并呋喃(DBF)和甲基二苯并呋喃(MDBFs)等化合物定量分析及正构烷烃单体C同位素组成分析,将油样分为Ⅰ、Ⅱ两类。与Ⅱ类原油相比,Ⅰ类原油具有:①相对较高的Pr/n-C17、Ph/n-C18值和较低的Pr/Ph值;②相对较高的伽马蜡烷/(C30藿烷+伽马蜡烷)值;③相对较高的C29甾烷异构化比值、三环萜烷/(三环萜烷+C30藿烷)值、三芳甾烷TA(Ⅰ)/(TA(Ⅰ)+TA(Ⅱ)值和甲基二苯并噻吩比值4-MDBT/1-MDBT;④相对较高的二苯并噻吩(DBT)和甲基二苯并噻吩(MDBTs)含量、较低的二苯并呋喃(DBF)和甲基二苯并呋喃(MDBFs)含量和较高的DBT/(DBT+DBF)和MDBTs/(MDBTs+MDBFs)值。其中,两类原油MDBFs含量和DBT/(DBT+DBF)、MDBTs/(MDBTs+MDBFs)值差异比较显著。此外,Ⅱ类原油正构烷烃单体C同位素分布型式具有一定程度的“倒转”,即随碳数增加δ^(13)C值先变轻,至n-C25达到最低值,之后变重,而Ⅰ类原油不具有“倒转”特征。Ⅰ类原油来源于下二叠统风城组烃源岩,Ⅱ类原油来源于中二叠统下乌尔禾组烃源岩与下二叠统风城组烃源岩的原油组分混合产物。Ⅰ类原油比Ⅱ类原油分布于相对较深的储层,两类原油具有不同的运聚通道和分布规律。

准噶尔盆地盆1井西凹陷石炭系—二叠系天然气特征及成藏主控因素

综合利用地震、钻井、测井、岩心、薄片、有机地球化学等资料,对准噶尔盆地盆1井西凹陷石炭系—二叠系天然气的地球化学特征、成因、来源、成藏主控因素以及勘探潜力进行了探讨。研究结果表明:①盆1井西凹陷深层石炭系—二叠系天然气中甲烷的体积分数为70.93%~96.55%,平均值为81.78%,总体为湿气。碳同位素分布相对较广,甲烷碳同位素值为−41.62‰~−30.42‰,平均值为-34.75‰,天然气大多处于成熟—高成熟演化阶段;乙烷碳同位素值为−31.69‰~−24.16‰,平均值为−27.50‰,可见天然气成因以煤型气为主,其次为混合成因气。C7轻烃化合物中甲基环己烷和正庚烷的相对含量均较高,甲基环己烷相对质量分数为32.14%~58.37%,平均值为38.84%,正庚烷相对质量分数为25.37%~56.56%,平均值为47.79%。②研究区天然气成因类型及来源复杂,主要来自于二叠系下乌尔禾组烃源岩的煤型气及其与风城组油型气的混合气,来自风城组烃源岩的油型气较少。③研究区二叠系风城组和下乌尔禾组烃源岩生气潜力大,多种岩性储层发育,断裂和不整合面渗透性砂体为深层天然气的运移成藏提供了输导体系,且石炭系的古凸起和二叠系的岩性圈闭形成互补之势,对天然气在斜坡区的聚集起到了良好的侧向遮挡作用。④研究区鼻凸构造带石炭系火山岩和洼槽二叠系风城组碎屑岩2类规模较大的勘探领域是下一步盆1井西凹陷深层天然气勘探的潜力区。

布尔津盆地西部凹陷乌伦古河组后生氧化作用及成矿潜力分析

布尔津盆地西部凹陷后生氧化作用类型分为潜水氧化和层间氧化。潜水氧化带是由地下水自上而下产生垂直地化分带而形成的,主要分布在乌伦古河组的顶部剥蚀面上有古潜水氧化带发现。层间氧化带是层间承压水侧向迁移而产生的地化分带,鉴于工作重点是寻找与层间氧化带有关的地浸砂岩型铀矿,本文仅对乌伦古河组沉积特征、层间氧化带的特征、铀的迁移和富集做一描述,分析区内铀成矿潜力,为下一步攻深找盲提供了依据。

辽河西部凹陷新生代断裂构造特征与油气成藏

为了揭示辽河坳陷西部凹陷新生代断裂构造与油气关系,运用油区构造解析理论对西部凹陷新生代断裂构造发育及演化特征进行系统分析。结果表明:以沙三段中下部大套泥岩为界,西部凹陷形成了上下叠加的2个断裂系统,主要发育长寿型、早衰型和后生型3种类型断层和张性正断层、走滑断层、走滑正断层和走滑逆断层4类不同性质断层。断裂活动控制了西部凹陷烃源岩的分布与演化、油气的运聚以及圈闭形成:断陷期是主要的烃源岩形成期,持续沉降有利于烃源岩演化;伸展变形阶段形成的下部断裂系统有利于油气的聚集,走滑变形阶段发育的上部断裂系统有利于油气的运移;构造活动强烈期是圈闭主要形成期,在沙四段—沙三段沉积早期及东营组沉积晚期形成两期主体圈闭。根据断裂发育特征和演化过程,指出双西隐伏走滑断层带和台安—大洼断层带的海外河以南部分是有利勘探区。

烃源岩有机质丰度的测井计算方法及影响因素探讨

近年来,结合丰富的地球物理信息和地球化学实验数据来研究烃源岩,可有效克服常规岩样分析资料连续性差、成本高的难题,且获得了广泛的应用,但在实际应用过程中发现,其准确性并非很高。文中以辽河西部凹陷为例,结合取心井SG1的烃源岩地球化学和测井资料,重点对比了不同成熟度范围的烃源岩的测井响应差异。通过讨论影响烃源岩TOC测井计算方法准确性的各种因素,对比了最小二乘法与ΔlgR方法的优缺点,认为最小二乘法拟合公式的3个常数(A,B,C)包含了多种影响计算结果的因素,因此,最小二乘法更能反映烃源岩层TOC的变化,且在应用时具有较强的可操作性。