Organic compositions of lacustrine source rocks in Jiyang super-depression and its implication to petroleum geology

IMMATURE OIL WAS FIRST DISCOVERED IN WELL YI18 IN CHINA [1]. FROM THEN ON, MORE AND MORE IMMATURE OILS WERE DISCOVERED IN JIYANG SUPER-DEPRESSION, FOR EXAM- PLE, SOUTHERN SLOPE OF DONGYING DEPRESSION, GUNAN SAG IN ZHANHUA DEPRESSION, TAOERHE, DAWANGZHUANG…     

The antipole evolution effect of immature-low mature organic matter ——Report from low-temperature low-pressure artificial hydropyrolysis experiment

The low-temperature and low-pressure artificial hydropyrolysis experiment proves that at the immature-low mature thermal evolution stage of source rock, the condensation reaction and the thermal degradation reaction occur continuously and simultaneously in both soluble organic matter and insoluble organic matter. This process was called "antipole evolution", which means transformation into two opposing extremes. The soluble organic matter and insoluble organic matter constitute an organic related integrity, transforming mutually in a dynamic equilibrium. Non-hydrocarbon and asphaltene are key intermediates between kerogen and hydrocarbon . Asphaltene is one of the major sources of immature hydrocarbons.     

The antipole evolution effect of immature-low mature organic matter

The low-temperature and low-pressure artificial hydropyrolysis experiment proves that at the immature-low mature thermal evolution stage of source rock, the condensation reaction and the thermal degradation reaction occur continuously and simultaneously in both soluble organic matter and insoluble organic matter. This process was called “antipole evolution”, which means transformation into two opposing extremes. The soluble organic matter and insoluble organic matter constitute an organic related integrity, transforming mutually in a dynamic equilibrium. Non-hydrocarbon and asphaltene are key intermediates between kerogen and hydrocarbon. Asphaltene is one of the major sources of immature hydrocarbons.     

二连盆地烃源岩有机质类型及有机相

二连盆地由５０多个断陷组成,主要的烃源岩是下白垩统巴彦花群,从烃源岩的干酪根及热解等资料分析来看,生油岩母质类型以Ⅱ１－Ⅱ２型为主,是典型的混合型生油岩;而烃源岩的可溶性有机质鉴定结果发现含有大量的高等植物标志化合物,说明早白垩世断陷湖泊有机质主要来源于高等植物,分析认为这一现象是由于高等植物“腐泥化”的结果,并通过有机相综合分析,明确了断陷群不同相带的生烃潜力及成油特征,并指明断陷群的勘探前景．     

半封闭半开放体系下不同演化程度干酪根的太赫兹光谱特性

本文应用太赫兹时域光谱技术研究了灰色泥岩在半封闭半开放体系下经历不同生烃模拟温度、压力所得干酪根的光学性质,获得了不同干酪根样品在太赫兹波段的吸收谱和折射率,结合样品的镜质体反射率,建立了干酪根在不同演化阶段的生烃模式,分析了干酪根样品在地质升温速率下的自然演化过程及主生烃期,为研究烃源岩的演化及油气生成提供了参考．     

内蒙古东北拉布达林盆地上库力组烃源岩生烃潜力分析

 应用有机岩石学、热解分析等地球化学分析技术,对拉布达林盆地下白垩统上库力组一段烃源岩进行干酪根元素分析、岩石热解分析和高温高压热模拟实验。探讨了拉布达林盆地下白垩统上库力组一段烃源岩的显微组分、有机质丰度、类型和成熟度等特征,分析了其生烃潜力和生烃属性。将上库力组一段烃源岩显微组分划分为壳质组、镜质组和惰质组3种类型,其中,壳质组中来源于水生生物的腐殖无定形体含量很高（94%～97%）,有利于生油;有机质丰度较高,达到中到好的级别;烃源岩有机质类型较好,主要为II1型和II2型;有机质热演化程度较低,主要处于生油的低成熟阶段。结果表明,拉布达林盆地上库力组一段烃源岩具备较好的生油潜力,具有很好的油气勘探前景。     

河北省下花园地区下马岭组碳酸盐生油岩热模拟实验

对下马岭组灰岩进行了热模拟实验,对碳酸盐岩腐泥型有机质的热演化规律进行了研究,划分了其演化阶段,给出了成熟度指标和各阶段油气产率.研究表明,矿物对有机质热演化的影响,在成熟阶段主要表现为催化作用;在高过成熟阶段则主要表现为对干酪根裂解、脱氧和缩合有阻碍作用.沥青“C”的某些成熟度指标可较好地反映有机质成熟度;在缺乏镜质体时焦沥青反射率可作为有效的成熟度指标.此外还对比了岩样和干酪根的模拟结果,以及沥青“A”和“C”的差异.     

源岩活化能分布最小值与有机质成熟度的关系

提出了一种确定源岩中干酪根活化能分布最小值的方法,并通过东营凹陷南斜坡东段沙四段源岩的动力学特征研究,发现源岩活化能分布最小值与有机质成熟度之间没有明显的正相关关系,而可溶有机质抽提后的源岩活化能分布最小值与有机质成熟度之间存在较为明显的线性正相关关系.     

Origin of immature sulfur-rich oil in Jianghan oil field

Chemical structure of immature sulfur-rich kerogen and composition of immature sulfur-rich crude oil in Jianghun oil field have been studied. In molecular level, crude oil differs from thermolysed and chemolysed products of kerogen but does resemble the bitumen in immature sulfur-rich source rock. Therefore, immature sulfur-rich oil may be derived from the expelling of bitumen rather than from thermal cracking of kerogen.     

Pb, Sr isotopes in organic matter of Lower Tertiary hydrocarbon source rocks in Liaohe Fault Depression

The Pb, Sr isotopic compositions in organic matters (kerogen and soluble organic matter) of Lower Tertiary hydrocarbon source rock in Liaohe Fault Depression is first reported. There is a great variable rang of Pb isotopic compositions in kerogen, 206Pb/204Pb = 17.488-18.656, 207Pb/204Pb= 15.388-15.692, 208Pb/204Pb = 37.656-37.484. And soluble organic matters have a very stable Pb isotopic composition, that is 206Pb/204Pb = 17.424-17.601, 207pb/204pb= 15.376-15.448, 208Pb/204Pb = 37.620-37.870. Sr isotopic composition varies in the range of 0.747 59-0.716 79 in kerogen and of 0.709 67-0.747 59 in soluble organic matters that have a great range. It is shown that mantle fluid can influence organic matters and make them form hydrothermal hydrocarbon in the geoglogic environment of rift basin.     

The role of sulfur in the pyrolysis of kerogen

Sulfur plays an important role in the generation and evolution of hydrocarbon from organic matter. Here, a pyrolysis experiment in closed system was performed on Maoming oil shales kerogen (Type Ⅰ), Maoming oil shales kerogen added with sulfur ether and Maoming oil shales kerogen added with sulphur. The results suggest that the existence of sulfur can result in: (i) higher yield of hydrocarbons generated from the kerogen; (ii) decrease of the temperature for the maximum generation of heavy hydrocarbons (the C15+ fraction) by 20℃; (iii) decrease of the temperature for the maximum generation of the aromatics fraction by 40℃, and (iv) acceleration of the aromatization process. The pyrolysates from kerogen added with sulfur are similar to the heating products of the sulfur-rich kerogen as reported in the literatures. It seems that the sulfur catalysis is also an important factor that can make the sulfur-rich kerogen generate low-mature oil at the earlier diagenesis stage, except for the weakness of the C-S and S-S bonds.     

全岩分析与干酪根分析的对比研究

全岩分析与干酪根分析是有机岩石学研究烃源岩的两种分析方法。笔者在简述这两种分析方法的基础上,系统对比了两者在油气评价中的应用。认为在显微组分特征、成因与分类,有机质丰度、类型与成熟度、烃类生成与运移特征等方面的研究中,全岩分析能提供更多的信息,且快速、经济、直观,较干酪根分析具有明显的优越性。目前虽还不能完全取代干酪根分析,但全岩分析必将发展成为今后有机岩石学研究的必需方法之一。     

Quantification and implications of two types of soluble organic matter from brackish to saline lake source rocks

Two types of soluble organic matter, the free and adsorbed, were obtained and quantified from the brackish to saline lake source rocks. The adsorbed type was extracted with chloroform, solvent mixtures of methanol：acetone：chloroform （MAC） and CS2：N-methyl-2-pyrrolidinone （CSz/NMP）. The total amounts of the two types of soluble organic matter from some immature source rocks are 〉830 mg/g TOC, more than 63% of the total organic matter in these samples. This result indicates that the majority of the organic matter in the immature source rocks in the brackish to saline lake basin is soluble, and is significant for study of petroleum formation and helpful for petroleum exploration in the brackish to saline lake basin.     

陆相砂泥岩层系中油气初次运移的定量化研究

分析了东濮凹陷东南部的油气地球化学特征,以濮深10井为例,计算了砂泥岩剖面的孔隙度和流体压力,以及不同性质生油岩在演化阶段的油气生成量。用生油岩孔隙中油气饱和度控制油气排出量的方法,可得到油气初次运移量和运移时期。研究表明,有机质丰度高、类型好的生油岩,在进入生油门限时期不久就有油气排出;而有机质丰度低的生油岩几乎无液态油排出,只会在高、过成熟条件下排出天然气。     

烃源岩中有机质测定及分布规律研究

烃源岩是一种富含有机质和各种无机矿物的集合体,而有机质是未熟-低熟原油和烃源岩抽提物的常见组分。采用不同方法对烃源岩进行有机质抽提并进行了四组分分析,考察了不同层位和深度有机质总抽提率和四组分的分布规律。结果表明,三元溶剂的抽提率相对较高,并且总体含量上在Es3有机质的含量较高,颜色深的页岩含有机质的量较高。     

鄂尔多斯盆地宜川地区上古生界烃源岩评价

依据氢指数（HI）、降解率（PC/TOC）等两个方面的地球化学指标,按照煤系地层烃源岩有机质类型划分标准,对研究区的山西-太原组烃源层的有机质类型作剖析,进行上古生界烃源岩系统评价。研究认为,本溪组烃源岩主要是泥岩,有机质丰度平均2.51%,泥岩干酪根母质类型主体属腐殖型干酪根,即Ⅲ型干酪根;太原组暗色泥岩有机质丰度平均2.26%,煤层比较发育,有机质丰度平均81.66%;山西组的泥岩比较发育,泥岩有机质丰度平均2.26%,煤层有机质丰度平均72.66%。本区上古生界干酪根显微组分都以镜质组为主,显示干酪根母质为腐殖型,即Ⅲ型干酪根,热成熟度演化较高,Ro都大于2.5%,Tmax为490℃以上,表明泥岩已达到过成熟阶段,本区暗色泥岩及煤层属中等—好气源岩,此次烃源岩的认识对该区下一步的勘探提供重要的依据。     

干酪根热解聚沥青中的脂烃生物标记物

将干酪根在超临界态溶剂存在下进行热解聚,抽出物中的脂烃生物标记物的分析表明,抚顺与茂名油页岩干酪根中有相当多的陆源高等植物参与生成。甾烧萜烷的成熟度参数表明,热解聚沥青的成熟度很低。对于干酪根通过热解聚形成未熟或低熟原油的可能性作了初步探讨。     

歧口凹陷沙一段低熟烃源岩评价

利用烃源岩有机质丰度、生排烃特征、发育古环境、有机岩石学及原油特征等手段,探讨歧口凹陷沙一段低熟烃源岩生烃、排烃特征。研究结果表明,歧口凹陷沙一段低熟烃源岩有机质丰度高、类型好,具有集中排烃、高效排烃的特点。沙一下段烃源岩发育的环境主要为干旱气候下的咸水环境。藻类及显微组分中的矿物沥青基质是低熟烃源岩形成低熟油气的物质基础。歧口凹陷存在大量未熟-低熟的原油。     

松辽盆地长岭坳陷上白垩统页岩油有利区优选及资源潜力

松辽盆地长岭坳陷的页岩油勘探尚处于起步阶段,上白垩统页岩油资源潜力研究将为该坳陷页岩油勘探提供科学依据和理论支撑。从泥页岩空间展布特点和有机地球化学特点等方面对该区上白垩统嫩江组和青山口组富有机质页岩进行了系统的分析。研究结果表明:松辽盆地长岭坳陷嫩江组一、二段和青山口组一段整体具有泥页岩厚度大、分布面积广,高有机质丰度、演化程度适中和偏生油型干酪根的特点。在此基础上,对松辽盆地长岭坳陷上白垩统页岩油进行了有利区的预测并初步分析了勘探潜力。     

生油岩原始有机碳恢复方法的探讨

本文在前人工作的基础上,根据物质平衡原理和热模拟实验揭示了干酪根演化过程,探讨了沉积有机质在热降解中的转化与“消耗”,确定了各种类型成油母质在不同成熟阶段中碳的演化规律,找出了生油岩实测有机碳与干酪根中碳的对应关系,提出了各种生油岩有机碳恢复系数。文中给出了泥质岩和碳酸盐岩的应用实例。