Dynamic simulation of gas hydrate reservoirs in the Shenhu area,the northern South China Sea

为进一步了解南海北部神狐海域天然气水合物的成藏匹配条件,利用典型二维地震剖面,构建了该区的地质模型,并对其进行了天然气水合物成藏动力学的模拟。研究结果表明:神狐海域具备天然气水合物成藏的温度、压力条件;生物气和热解气的资源潜力巨大,满足水合物形成的气源条件;运移条件优越,有利于天然气水合物的聚集成藏。并提出了该区天然气水合物的成藏模式。The north slope of the South China Sea is structurally characterized by a passive continental margin and has various Cenozoic oil-and gas-bearing depositional basins,where hydrocarbon resources are abundant,and the geological and tectonic settings,the temperature and pressure regimes as well as the methane-generative potential of thick organic-rich sediments are all favorable for the formation of gas hydrate.As a result,this region is also an ideal area for studying gas hydrate accumulations.In order to understand natural conditions of the gas hydrate formation,based on the typical 2-dimensional seismic image of the Shenhu area,a geological model of gas hydrate reservoirs was established and a dynamic simulation of gas hydrate accumulations was carried out as well.The results indicated that the temperature and pressure of the Shenhu area are appropriate for gas hydrate accumulations,source rocks there have a huge gas-generative potential and hydrocarbon migration conditions are favorable,providing an abundant gas source and good pathways for the gas hydrate formation.A forecasting model of the gas hydrate formation was given based on basin analysis,indicating that the Shenhu area is a better prospect area of gas hydrate because of its huge potential of gas hydrate resources.国土资源部公益性行业科研专项(200811014)“天然气水合物成藏的控制因素研究”;国家自然科学基金项目(No.40930845)“南海北部深水盆地油气渗漏系统与天然气水合物富集机制研究”;国家重点基础研究发展规划(973)项目(2009CB219501)“南海北部天然气水合物成藏的气源条件研究”联合资

Logging Response Characteristics of Gas Hydrate Formation in Shenhu Area of the South China Sea

分析了南海北部神狐海域含天然气水合物沉积层声波速度及密度的分布特征和变化规律,并通过对比dSdP 84航次570号钻孔含天然气水合物层段测井资料,总结出神狐海域含水合物地层的测井响应规律特征:神狐海域含水合物地层存在着明显的高声波速度、低密度特征,地层密度随声波速度的变化并不是单一的反比例关系,总体趋势上随声波速度的升高而降低;含水合物地层高声波速度值主要集中在197--220 M段,饱和度值在15%--47%之间,低密度值集中在200--212 M段,分布在水合物饱和度大于20%的地层内;含水合物地层声波速度平均值为2 076 M/S,其上覆和下伏地层的声波速度平均值为1 903 M/S和1 892 M/S,所对应的地层密度值分别为1.89 g/CM3、1.98 g/CM3和2.03 g/CM3,声波速度受孔隙度和饱和度的共同影响,地层密度受水合物饱和度影响较大;从水合物上覆地层到声波速度最高值段,声波速度值增加了9.1%,相对应的地层密度值减少了4.55%,从水合物声波速度最高值段到下伏地层,声波速度值减少了8.86%,相对应的地层密度值增加了7.41%。这些测井响应特征,可用来识别地层中天然气水合物,并可以用来计算水合物的饱和度,同时结合其他地质和地球物理资料,确定水合物层的厚度、分布范围,计算天然气水合物的资源量。With analysis of the distributing feature and the changing law of the sonic velocity and density of sediments with gas hydrate in Shenhu Area of the South China Sea,by comparing with logging data of gas hydrate formation at Site 570 of DSDP 84,the logging response characteristics of gas hydrate formation in Shenhu Area were conducted.The results show that:(1)Sediments with gas hydrate in Shenhu Area have the clear features that the sonic velocity is high and density is low,and the density is generally decreased with the increasing of the sonic velocity.(2)The high sonic velocity section in sediments with gas hydrate is in the depth of 197 to 220 m,and the low density section is in the depth of 200 to 212 m;the value of saturation is in the range of 15%to 47%.(3)The average sonic velocities of sediments with gas hydrates and the overlying strata and underlying strata are 2,076 m/s,1,903 m/s and 1,892 m/s,respectively,and the corresponding densities are 1.89 g/cm3,1.98 g/cm3 and 2.03 g/cm3,respectively;sonic velocity is effected by porosity and saturation,and density is greatly influenced by saturation;(4) The sonic velocity increases by 9.1% from the overlying strata of hydrates to the maximum-value section,and the corresponding density decreased by 4.55%;the sonic velocity decreases by 8.86% from the maximum-value section to the underlying strata of hydrates,and the corresponding density increases by 7.41%.The logging response characteristics can be used to identify the existence of gas hydrates and to calculate the saturation of gas hydrate,furthermore,to provide accurate area and thickness of gas hydrate zone for calculating gas hydrates reserves with combination of other geological and geophysical data.中国科学院边缘海地质重点实验室项目(MSGL08-03);国家重点基础研究发展计划(2009CB219508

The Seismic Detecting Technique on Gas Hydrates Based on Wave Impedance Inversion

天然气水合物作为特殊的地质体,可以有效地粘结碎屑颗粒,降低沉积物孔隙度,它的存在改变了地层沉积物的物理性质,造成天然气水合物与围岩速度反差较大,从而与围岩之间存在明显的波阻抗差。为了对地层中是否有天然气水合物赋存进行地震检测,对南海北部神狐海域的天然气水合物赋存区域的地震资料进行波阻抗反演分析,结果显示波阻抗反演方法能够作为探测天然气水合物的一种技术手段,研究区天然气水合物矿体的波阻抗呈高值分布特征,波阻抗值约为3 850--3 960 g/CM3.M/S。综合分析认为,波阻抗反演方法能够用于天然气水合物的地震探测、储层分析和综合研究工作中,反演结果可以为天然气水合物储量计算提供比较准确的矿体面积和厚度参数。As specific geologic body,gas hydrate can cement effectively clastic particles and reduce porosity of deposition,so its presence changes physical property of the sedimentary strata and results in the difference of seismic-wave velocity between gas hydrate and the surrounding rock,and there exists obviously wave impedance difference.In order to detect the presence of sediments with gas hydrate,seismic data of gas hydrate zone in the Shenhu area of the northern South China Sea were used in the wave impedance inversion through practice,testing and summary.Wave impedance inversion method is considered as a kind of good seismic detection technique for identification of gas hydrates,meanwhile,the wave impedance of gas hydrate zone shows high value in the study area,and the wave impedance value is about 3,850-3,960 g/cm3·m/s.All the results suggested that wave impedance inversion can be used for detection,reservoir analysis and comprehensive research of gas hydrates.The wave impedance inversion results can provide comparatively accurate area and thickness parameters of gas hydrate zone for reserves calculation.国家高技术研究发展计划项目(2006AA09A202);国土资源部公益性行业科研专项项目(200811014);国土资源部海洋油气资源与环境地质重点实验室资助项目(MRE200911);国家重点基础研究发展计划项目(2009CB219502

Using the Well-Seimic Unite Carries on the Three Dimensional Seimic fine Explanation

针对苏北gz地区三维地震解释需要,在常规三维地震解释的基础上,制作精细合成地震记录标定层位,同时,应用的井、震联合技术对地震资料进行构造解释,为测井资料的对比提供了有利的依据。总体上突出了构造解释的细致性、准确性和客观性,为下一步的油藏评价和开发提供了依据。In view of northern Jiangsu GZ area three dimensional seismic interpretation need,In convention three dimensional seismic interpretation foundation,Manufactures the fine composite trace demarcation position,simultaneously,the application well,shakes the union technology to carry on the structure to the earthquake material to explain,has provided the advantageous basis for the log information contrast.As a whole has highlighted structure explanation careful,the accuracy and the objectivity,has provided the basis for the next step oil deposit appraisal and the development

Optimization Design of 3-D Seismic Observation System Based on Geophysical Forward Model

针对四川盆地大邑地区复杂的地下构造,构建了该区的地球物理正演模型,利用射线追踪正演及全波场波动方程的正演模拟分析,进行了地震采集参数的论证和三维观测系统的优化选择,进而讨论了采集方法的适应性。研究结果表明,优选的观测系统,能极大地改善剖面的品质和提高地下复杂地质体成像精度。Dayi area in Sichuan basin is characterized by complicated subsurface structures.In the previous exploration,the seismic observation system was not effectively designed for the oil-enriched object area,leading to inconspicuous event set and fault points on the seismic profile and failing to understand structures.In order to clarify the occurrence,property and distribution of two major faults in this area,this paper presents the geophysical forward model of this area,conducts the seismic data acquisition demonstration and the optimization design/selection of the 3-D seismic observation system using ray tracing forward modeling and full wave field equation analysis and discusses the suitability of the data acquisition.The results show that the 3-D seismic observation system optimization design and selection can be able to greatly improve the quality of the seismic profile and the imaging accuracy of geologic bodies in this area.国家自然科学基金项目(40472156);973项目(2009CB219501

南海北部陆坡泥底辟/气烟囱基本特征及其与油气和水合物成藏关系

以南海北部陆坡深水区琼东南盆地南部及珠江口盆地白云凹陷地质地震资料为基础,综合分析了泥底辟及气烟囱分布特征、发育演化特点、成因机制及其与油气和水合物成藏的关系。研究结果表明：泥底辟及气烟囱主要相对集中发育于凹陷中心或凹陷与凸起构造转换带,具有杂乱模糊地震反射特征且其模糊带形态各异；泥底辟及气烟囱展布规模大小不一,刺穿层位及幅度亦存在明显差异,且常常伴生强烈的热流体活动；泥底辟及气烟囱形成受控于沉积充填的巨厚欠压实泥页岩及其伴生的高温超压潜能、断层裂缝及构造薄弱带和有机质生烃增压等地质因素；泥底辟与气烟囱及其伴生断层裂隙是深部气源向浅层运移聚集的优势通道,通过这些流体运聚的高速通道,可以将其运移至上覆新近系储层和深水海底浅层高压低温稳定域,最终形成深部常规油气藏与海底浅层天然气水合物矿藏纵向叠置复式聚集的组合特点

CHARACTERISTICS OF MUD DIAPIR AND GAS CHIMNEY AND THEIR RELATIONSHIP WITH RESERVOIR FORMING FOR PETROLEUM AND NATURAL GAS HYDRATE ON NORTHERN SLOPE OF THE SOUTH CHINA SEA

以南海北部陆坡深水区琼东南盆地南部及珠江口盆地白云凹陷地质地震资料为基础,综合分析了泥底辟及气烟囱分布特征、发育演化特点、成因机制及其与油气和水合物成藏的关系。研究结果表明：泥底辟及气烟囱主要相对集中发育于凹陷中心或凹陷与凸起构造转换带,具有杂乱模糊地震反射特征且其模糊带形态各异；泥底辟及气烟囱展布规模大小不一,刺穿层位及幅度亦存在明显差异,且常常伴生强烈的热流体活动；泥底辟及气烟囱形成受控于沉积充填的巨厚欠压实泥页岩及其伴生的高温超压潜能、断层裂缝及构造薄弱带和有机质生烃增压等地质因素；泥底辟与气烟囱及其伴生断层裂隙是深部气源向浅层运移聚集的优势通道,通过这些流体运聚的高速通道,可以将其运移至上覆新近系储层和深水海底浅层高压低温稳定域,最终形成深部常规油气藏与海底浅层天然气水合物矿藏纵向叠置复式聚集的组合特点

IE701离子交换树脂对胆红素吸附性能的研究

考察了自制的IE701离子交换树脂对胆红素的吸附性能。25℃时树脂对游离胆红素和人血清白蛋白结合胆红素的平衡吸附率为97．1％和86．4％，进口产品MARS IE250离子交换树脂则分别为96．3％和91.3％

南海北部琼东南盆地天然气水合物成藏数值模拟

为查明南海北部琼东南盆地生物成因和热成因天然气的资源潜力及其对天然气水合物成藏的贡献,根据琼东南海域天然气水合物调查区典型二维地震剖面,构建了该区的地质模型,并结合区域内岩性、地热和地球化学等参数对其进行了天然气水合物成藏的数值模拟。结果表明:琼东南盆地具备天然气水合物成藏的稳定域范围,稳定域厚度介于220~340m之间;生物气和热解气的资源潜力巨大,满足天然气水合物形成的气源条件;运移条件优越,有利于天然气水合物的聚集成藏。最后根据气体来源及其运移特征讨论了该区域天然气水合物成藏的地质模式

富生烃凹陷背景下热成因气对水合物成藏的贡献探讨

近年来海域水合物的实际钻探结果显示，当富生烃凹陷具有适宜的水深、温度、压力等地质条件时，浅部沉积物往往是水合物的潜在富集区域。尽管富生烃凹陷具有优异的生排烃潜力，热成因气较为充足，为水合物的形成提供充足的气体来源，但实际调查表明浅部地层中水合物的气体组分和碳同位素更多地表现为微生物成因气或混合成因气的特征，并没有深部热成因气形成的天然气水合物广泛发育的特征。2007年和2015年在我国南海北部陆坡神狐海域白云凹陷进行了两次水合物钻探，与2007年获取的具有微生物成因特征或热成因气贡献非常小的混合成因水合物相比，在2015年钻探中，有钻孔站位的烃类组分测定揭示了较高含量的乙烷和丙烷，从而直接证实了该站位的水合物气源主要是热成因气。白云凹陷内油气钻井地球化学测试分析显示，虽然深部烃类气体受东沙运动的影响存在大规模的逃逸和散失，但部分热成因气仍然可以通过断层、底辟和气烟囱等垂向通道运移至浅部地层之中形成天然气水合物。通过两个钻探区“深部烃源层系-中部运移通道-浅部水合物矿体”三者的垂向耦合对水合物成藏的控制研究，指出通道类型和运移效能的差异可能是导致同-富生烃凹陷背景下的两个水合物矿藏存在差异的主要原因。对于2007年钻探区而言，在深部热成因气沿着效能较低的通道发生自下而上的长距离运移过程中，可能会发生气体组分分异和碳同位素分馏等作用，导致气体的地球化学更多地表现为“微生物成因气”的特征。而在2015年钻探区，由于断裂、底辟构造发育，深部热成因气可以被更有效地输送至水合物成藏沉积地层中，气体组分和同位素没有发生显著的变化